Machine Vision

یک ذهن همواره در حرکت (۴)

Chapter Six—In the New World: Refugee at Berkeley (1938–1943):
Smell of Cyclotron Oil

Tu lascerai ogni cosa diletta
più caramente; e questo è quello strale
che l'arco dello essilio pria saetta.
. . . . . . . . . . . . . . . .
per lui fia trasmutata molta gente,
cambiando condizion ricchi e mendici

(Thou shalt leave all that thou hast loved most dear;
This is the arrow, shooting from the bow
Of banishment, which thou hast first to fear.
. . . . . . . . . . . . . . . . . . . . . . .
Through him shall many taste an altered lot,
The beggar and the rich exchanging place.)
Dante, Paradiso 17.55–57, 89–90 (trans. Laurence Binyon)

I landed in New York on July 13, 1938, expecting to return to Italy in the autumn for the beginning of the school year. Instead, nine years were to elapse before I revisited Italy. By that time, having lost my Italian job, I had built a second career, participated in great historic events, won a superior university position, and become a U.S. citizen and a Californian. Fate had been kind to me, although I had had my share of "blood, sweat and tears." I am grateful that I was spared both morbid homesickness and the terrible disasters that befell our parents and many of my friends. In my early American years I was lucky to have in science an absorbing occupation that both gave me pleasure and helped me rebuild my life.

On my arrival at New York, I visited my Columbia University friends and then, after a few days, left for Berkeley. I wanted to execute my work program as fast as possible. Leo Szilard, the Hungarian physicist I had met a few years earlier in England, came to see me off at Grand Central Station on my departure for San Francisco. He inquired about my plans, which I detailed to him. When I told him I expected to return to Palermo in October, he said that would be impossible because of what Mussolini might be expected to do; Italy might adopt Hitler's racist politics, and in any case, Hitler might start a world war soon. With these cheerful thoughts, I started on the first leg of my trip, from New York to Chicago.

At Chicago I bought a newspaper and read a short but chilling news item on the new charter of anti-Semitism in Italy, the Manifesto della razza (race manifesto), which obviously Mussolini had encouraged, even if it bore only the signatures of his minions.[1] I ruminated for the rest of the trip on its contents and implications. I decided not to mention the subject to strangers in Berkeley, however, until I knew more.

I was thus catapulted from my apparently secure job in Palermo into a precarious new situation. It is true that I was not unknown as a scientist, but my prestige was not sufficient to place me in the category of those for whom it was easy to find a job. Furthermore, I had arrived a few years later than contemporaries like Bethe, Bloch, and Teller, and the job market was more saturated. Strangely, the first shock did not affect me very much emotionally. The blow was not unexpected, and all in all I was too busy trying to rebuild my life to brood aimlessly. The result was that I did not feel the sudden rending from my previous life as an irreparable wound, as happened to many émigrés.

On my arrival in Berkeley, I immediately tried to look up my friend Lorenzo Emo, but he was away for a few days. The owner of the house where he lived had another room for rent and I took it. In that house I found a little book of Admiral Nelson's letters to Emma, Lady Hamilton, his lover. In them Nelson often complained about seasickness and signed with his Neapolitan ducal title, Bronté. Thus, in our friendly intercourse, I nicknamed Lorenzo "Bronté" or "Brontuzzo."

Lorenzo was of the greatest help to me in my early days at Berkeley. First, he explained to me the university minuet that one danced at Berkeley, as one does in all universities; then he guided me a little among the various personalities I met. Above all, he was a trusted friend with whom I could share my worries about what was happening in Europe. Between us we could talk with open hearts, sure of mutual understanding. In those weeks our acquaintance grew into a solid, intimate friendship that lasted for life.

Lorenzo, a handsome man, a man of the world, a count, and of independent means, was most popular among physicists and their wives, both at the university and at the Radiation Laboratory. Although he looked to be a farfallone amoroso (amorous butterfly), he was an astute observer of people and shrewdly appraised them. The first people I met through him were Don Cooksey (Lawrence's alter ego), Francis Jenkins and his wife Henriette, and Robert Brode and his wife Bernice.[2] In addition, Lorenzo introduced me to Dr. Giacomo Ancona, a physician from Florence living in San Francisco, who we discovered had examined me in 1926 when he was a young assistant to the professor of medicine at the University of Florence, Frugoni. I also struck up a close, lifelong friendship with Ancona.

I looked around the lab and saw at once that, while the cyclotron was a wonder, the methods used to measure radioactivity left much to be desired. I then tried to secure an ionization chamber of the type I had used in Rome and Palermo, and finding that Franco Rasetti, on a short visit in 1935, had left parts of such an instrument in Berkeley, I completed it. I was used to coupling the ionization chamber to an electrostatic electrometer, but when I asked Lawrence to buy such an instrument, he denied my request. He said that it was old-fashioned stuff, and that I should build a DC amplifier with an FP 54 tube. I had no choice and started working. Fortunately, Lee DuBridge, the future president of Caltech, then a professor at Rochester University, was vacationing in Berkeley. He was an expert on DC amplifiers and kindly offered his help, rapidly assembling the rest of the instrument. The resultant simple apparatus was used later for many investigations. It is now a museum piece at the Smithsonian Institution in Washington, D.C.

The more familiar I became with the Rad Lab, the more surprised I was; it operated very differently from any other laboratory I had been in. There were many students, but they seemed to me to be left to themselves, without scientific guidance. I was simple-minded or imprudent enough to mention this to Lawrence, and I even offered to help in guiding students. He answered me rather coolly that the Rad Lab and America were not a German university with a big boss dominating the students; that here students were free and learned by themselves, and similar tales.

The truth was that Lawrence's interest centered on the cyclotron and on building the Rad Lab's diverse activities; his knowledge of and interest in nuclear physics were limited. Students, in practice, served as cheap labor for the building and tending of the cyclotron and any move that might divert them from this task was frowned upon. It was difficult for me to understand the scientific policy of the Rad Lab. The cyclotron was a unique device, with seemingly infinite potential, but the main concern of those who controlled it was apparently to make the machine bigger and put it to work in areas outside of physics; there was little thought given to making proper use of what was on hand for nuclear studies.[3]

In hindsight I now believe Lawrence's attitude was more far-sighted than I then deemed. The concentration of effort was necessary in order to develop the machine, and Lawrence tried to do what he knew best. His early efforts in the nuclear field had not been a success and may have left him with unpleasant memories. The cyclotron in 1938 was still a relatively simple machine and could be developed primarily by empirical procedures, without a deep understanding and an elaborate theory of its functioning. To some extent, the methods used initially at the Rad Lab resembled the approach to technical development of an Edison or a Marconi; Lawrence fitted the same slot: brawn prevailed over brain. Financial support was what limited the development of the machine, and Lawrence spent most of his time raising money from foundations, from the university, and from anywhere else he could get it.

In the Rad Lab there were men of greatly differing ability, but all were young. L. W. Alvarez and Ed McMillan were obviously first-class scientists.[4] Emo had described the first to me as a little fascist leader, fawning to the Duce, but mean to his equals or inferiors. McMillan, according to Emo, was very clever, but lazy. They were the only ones who also had University of California appointments. Of the others, R. L. Thornton, M.D. Kamen, and R. R. Wilson were more than able. Thornton, in addition, was a true gentleman, brought up English-style, who combined technical prowess with superior human qualities. Kamen worked as a physicist and a chemist to earn a living but his heart was in music, and if he could have afforded to do so, he would have become a professional musician.[5] Wilson had his roots in the Wild West, but made a serious effort to civilize himself. At Berkeley, he and McMillan were the first to make a serious experimental study of the fine points of the workings of the cyclotron and to try to understand them theoretically. Outside of Berkeley, Hans Bethe, Morris Rose, and L. H. Thomas had applied sophisticated theory to accelerators, but had less contact with the realities of the problems.

At a somewhat lower level, there were Paul Aebersold, David Kalbfell, Robert Cornog, Philip Abelson, and many other graduate students or young postdoctoral fellows. They had sufficient ability, but, I believe, would have profited from more guidance. In addition, there was a whole group of medical doctors using radiation as a clinical and research tool. They were privileged because money came to a large extent from foundations nourishing optimistic hopes of medical applications, especially cancer cures.

Don Cooksey had a unique position. He came from a rich, cultivated family and had met the young Lawrence at Yale, where Cooksey and his brother Carleton were both members of the physics staff. Cooksey had limited scientific ambitions, but an immense love for and confidence in Lawrence. He devoted his considerable technical ability, his refined manners, his generosity and human understanding, to helping Lawrence in every way. Lawrence reciprocated by making Cooksey his most intimate confidant and advisor.

Soon after my arrival in Berkeley, I met Glenn Seaborg at the Faculty Club. He had obtained his doctorate the previous year and was a research assistant to G. N. Lewis, a famous chemist and one of the most important members of the Berkeley Faculty. Seaborg was keenly interested in anything happening around him and kept his ears and eyes open. Almost immediately he offered me his cooperation, which I gladly accepted. I found that he knew analytical chemistry according to the system propounded by A. A. Noyes and W. C. Bray,[6] rather than the more classical schemes I was familiar with. It seemed to me he knew everybody in the Chemistry Department and could find anything we needed. At the time Seaborg had a heavy load helping Lewis in his organic chemistry research, as well as in anything else that Lewis's fertile mind came up with. On the side he worked on nuclear problems for several hours every day and compiled data for an important review article he was preparing, as well as for a table of isotopes.[7]

Seaborg could do all this because he had iron discipline, a lively and highly systematic mind, immense persistence, exceptional endurance for work, and a sincere, open-minded interest in science. He was a superb organizer, but was not too strong in physics or instrumentation. At the beginning of our collaboration, I probably remembered my much earlier experience with Bakker at Zeeman's laboratory in Holland, when I, a newcomer, and he, the local boy, greatly helped each other and became steadfast friends. Little did I recognize Seaborg's unbridled ambition and his unshakable determination to succeed and to be preeminent.

As a general guideline for myself, I decided to fulfill my obligations as a citizen of the Cyclotron Republic but, at the same time, to try to preserve my individuality and to avoid being absorbed completely by the Rad Lab. I also wanted to use the immense opportunities offered by the cyclotron as much as possible, which I considered a contribution to the Lab. I soon found students willing to work with me. The first was Chien-Shiung Wu, who joined me when she realized that, in so doing, she would be able to learn something. She was very handsome, and very elegant in her Chinese dresses. When she walked on campus, she was often followed by a swarm of admirers, like a queen. She was a fiend for work, almost obsessed by physics, highly talented, and very shrewd, as well as witty. Many years later she became world-famous for the experimental demonstration of the non-conservation of parity. I admired her and liked her, and we remained friends for life.

Alex Langsdorf, Jr., a postdoctoral fellow, also started working with me. Disappointed with Lawrence, he had begun building a continuously operating cloud chamber, but this project ran into difficulties, and Alex joined me. He was the son of a well-known professor of electrical engineering at Washington University in St. Louis; while we worked, he diligently instructed me in things American, and we became steady friends.

A few days after my arrival, I started my first investigation, with Seaborg, a search for short-lived technetium isotopes. This was the natural continuation of my work at Palermo, the reason for which I had come to Berkeley in the first place. One of the new radioactivities, obtained by deuteron bombardment of molybdenum, immediately presented an unexpected and interesting nuclear phenomenon; it was a case of nuclear isomerism—that is, of a nucleus possessing long-lived excited states. We did not dream then that this isomer would in time become a mainstay of nuclear medicine as a powerful diagnostic tool. Today it is used by thousands of practitioners, and its applications are the basis of a multimillion dollar industry.

However, what interested us at the time was the phenomenon of nuclear isomerism. In 1936 C. F. von Weizsäcker had proposed a theoretical explanation of isomeric states, attributing to them a high angular momentum that forbids transitions to lower, small angular momentum states. It followed from this, according to theory, that there should be plenty of internal conversion electrons. Seaborg and I looked for them and found them, reporting our results in a letter to the Physical Review on September 14, 1938. A few days later, however, on the advice of J. Robert Oppenheimer, who for reasons unknown had told him (but not us) that we were mistaken, Lawrence demanded that we wire the editor of the journal to stop publication of our letter. I protested within the limits permitted by my position, and the letter was resubmitted to the Physical Review on October 14, 1938, after Bruno Pontecorvo had reported getting results on rhodium similar to ours.[8]

This was one of my first contacts with Oppenheimer, then professor of theoretical physics at Berkeley, later famous for his part in building the atomic bomb, for his political activity, and for his unjust victimization.[9] At the time, he was considered a demigod by himself and others at Berkeley, and as such he spake in learned and obscure fashions. Besides, he knew quantum mechanics well, and in this he was unique at Berkeley. He taught it in none too easy a fashion, which showed off his prowess and attracted a number of gifted students. His course later formed the basis of Leonard Schiff's well-known treatise on quantum mechanics.[10] Oppenheimer's loyal disciples hung on his words and put on corresponding airs. Just as we in Rome had acquired Fermi's intonation, in Berkeley Oppenheimer's students walked as if they had flat feet, an infirmity of their master's.

Oppenheimer and most of his acolytes followed the political line of the Communist Party of the United States, which was highly uncritical and simple-minded. Although most of these young people were not members of the Party, some were members of auxiliary organizations and later fell victim to cruel persecutions. Oppenheimer and his court did esoteric things; they read very highbrow books, cooked and ate unusual food, and during the summer went to a mountain ranch in New Mexico leased by Oppenheimer, beautifully located near Santa Fe. Their physics was valid, but often they attacked problems prematurely, or problems beyond their capabilities, resulting in indifferent success. The best of Oppenheimer is perhaps his astrophysical work on neutron stars, which many years after his death proved truly prophetic. His research on cosmic rays and atomic and nuclear problems embodied many good and even prescient ideas, but was often inconclusive. Oppenheimer's beneficial influence on the development of theoretical physics in the United States was considerable, and several of his pupils have achieved major results, as well as deserved fame.

Oppenheimer and his group did not inspire in me the awe that they perhaps expected. I had the impression that their celebrated general culture was not superior to that expected in a boy who had attended a good European high school. I was already acquainted with most of their cultural discoveries, and I found Oppenheimer's ostentation slightly ridiculous. In physics I was used to Fermi, who had a quite different solidity, coupled with a simplicity that contrasted with Oppenheimer's erudite complexities. Probably I did not sufficiently conceal my lack of supine admiration for Oppenheimer, and I found him unfriendly, even if covertly, for a good part of my career, except when he wanted me to join his team at Los Alamos.

At Berkeley, in 1938, I had the impression that Oppenheimer regarded me as a great Fascist. I was a Fascist Party member, as every Italian state employee was required to be by law, but it did not take much acumen to figure out that I could not be a Fascist at heart. I could not, however, conceal my skepticism when I heard him repeat, with the faith of the true believer, the nonsense originating from Stalin's Cominform.

Talking politics with American colleagues, I found an incomprehension of things European that was appalling to me. My partners in conversation had many different opinions, but most seemed convinced that what happened in Europe did not concern the United States, and that if the Americans minded their own business, they could avoid entanglements in European quarrels. It was, fundamentally, the isolationist thesis; they did not grasp Hitler's nature and his plans of world domination. These plans were the products of a deranged mind, but the disease had spread to a whole nation as powerful as Germany, and it was not something to trifle with. There was also a good measure of optimistic skepticism about Hitler's true intentions, which in effect proved much worse than the most pessimistic forecasts.

Others, although not many, followed the Communist Party line, like Oppenheimer, and deemed that the European quarrels were caused by capitalist imperialists, and that Holy Communism would avoid them. Which side of the bad capitalists won was irrelevant. If they weakened themselves sufficiently in their internecine strife, Mother Russia would later establish the millennium. This senseless view suddenly changed when Hitler and Stalin signed their nonaggression pact. Hitler suddenly became palatable!

My guts rebelled when I heard such talk. I strove to persuade isolationists that things were not as they hoped and believed. For the Communist true believers, there was nothing to be done, because their "ideas" were more religious feelings than political reasoning. Fortunately, President Roosevelt saw farther and more clearly than the majority of Americans. Anyone who was in the United States in the years immediately preceding World War II knows the difficulties Roosevelt faced in opening the eyes of the Congress and of the American people on the subject of Hitler.

I followed the news from Italy with increasing alarm, but I could relieve my feelings and unburden myself only with Emo. The Fascist Manifesto della razza had been followed by legal measures that left no doubt about the final purpose of the campaign. I recognized more and more the foresightedness and wisdom of having preserved a certain amount of money abroad. By the end of July, I had decided to forget Palermo and to summon my wife and son to California.

In the meantime, to escape the summer heat, Elfriede had taken Claudio to Frassenè, a resort in the Alps, where she was shortly joined by her parents from Germany. The publication of the Manifesto della razza followed a few days later. Elfriede was less alarmed than I, because Italian newspapers published a version of the facts that played down the probable consequences. When I wrote asking her to pack up and come to America, however, she agreed immediately.

In the following months, Elfriede had to face a heavy burden, first alone in Italy, and then in America. To start with, in Italy, she was confronted with sticky bureaucratic problems that required infinite patience, while the sultry summer weather and the effort of taking care of a one-year-old child further sapped her strength. She had good help, but the proceedings were morally debilitating and physically exhausting. All this emerges from her letters of the time.

In the meantime, the Czechoslovakian crisis was progressing and seemed likely to precipitate a world war. I thus urged Elfriede to speed up her departure, cabling her: "Vieni immediatamente con tuo comodo" (Come immediately, at your leisure), counting on her realizing that the first two words were the key ones.

Finally, Elfriede had to return to Sicily, lock up our apartment, and board a ship. She arrived in Palermo dead tired and sick with digestive troubles. There she was met at the dock by my student Ginetta Barresi, whom she had told she was coming. Ginetta was accompanied by her father, a colonel in the army, and by two other gentlemen. They asked without further ado what Elfriede needed. She explained the state of her passport—that it had the necessary Italian validation, but no U.S. visa—and said she wanted to close up our apartment and depart as soon as possible. The answer was immediate and to the point. "The next ship leaves on . . ." and they gave the date. "You get some rest now, and we'll take care of EVERYTHING ." I do not know whether Elfriede went to our apartment or to the Barresis' villa at Mondello; in any case, they brought her food and, three or four days later, in time for embarkation, her visa, the ticket, and everything she needed. As far as closing the apartment and forwarding its contents were concerned, Ginetta asked for instructions and in due course took care of everything to perfection. Moreover, Ginetta visited my parents whenever she was in Rome and sent us news of them. "I am pleased my compatriots are showing themselves to be decent people. Having gotten to know Ginetta and her like better, however, I shall become a Sicilian by choice," I wrote to my parents on August 3, 1939, responding to a letter of theirs in which they took comfort in the signs of friendship and esteem they were receiving in Tivoli. From Ginetta we had proofs of friendship in "heroic degree," as the Church says of virtue.

In 1938 and 1939 my parents continued to live more or less as they usually did, at least on the material side. They traveled a good deal, vacationing at Forte dei Marmi or some other familiar resort when Rome was too hot, and spending long periods at Tivoli. In almost all their letters, they mention old friends, above all Signora Rasetti and Amaldi, Bernardini, and other physicists who went to visit them and tried to cheer them up. In these letters, my father's great moral strength, clarity of mind, and farsightedness are also apparent. He never loses sight of the essential point. In rereading my parents' letters half a century later, I am impressed.

It was an anxious time. I was afraid that hostilities might break out while Elfriede and Claudio were on an Italian ship, and that they might be detained at Gibraltar for the duration of the war. Furthermore, in view of the circumstances, I had cabled certain instructions concerning my funds, and I received an answer in a commercial code that was incomprehensible without the key. I confided this to Emo, who, half jokingly, half because he did not know what to say, indulged in the blackest hypotheses on the mysterious meaning of the words of the cable I had received. "Homgo Homil," it began, and Emo said that this obviously meant "All is lost!"; for many years these words remained our private joke. Finally, I found a European apprentice at a bank in Berkeley who recognized the code and translated it for me. It was nothing important, but at the time, Emo and I were so upset by the events that we lived on milk shakes only; we could not eat because any solid food disagreed with us.

At the worst of the Czechoslovakian crisis, Elfriede, in blissful ignorance of everything, was at Gibraltar on an Italian liner, but the situation cleared up, at least temporarily, and she was able to proceed to New York. There she caught a train, and since it was her birthday, October 2, I sent her a telegram, using one of those long and pompous standard texts delivered on a special birthday form, all for twenty-five cents. "The darkest clouds have a silver lining," it declared among other things. On receiving the telegram en route in a style so unnatural for me, and unaware of Western Union's bargain services, Elfriede thought I had lost my mind. Finally, in early October, we were reunited, to our great mutual joy.

During the summer I had also started to become acquainted with some of the attractive features of life in the United States under the guidance of Brode, Jenkins, and their wives. As one of the first lessons, the husbands and their friend S. K. Allison, a physicist from the University of Chicago,[11] took me for a long hike in Yosemite National Park. We visited the high mountains near Vogelsang Pass, from where, in a couple of days, we descended into the Valley, walking along the Merced River. Jenkins had brought along an extra rod and he showed me how to fish for trout. Within an hour I was hooked on the sport, which delighted me for many years. My three physicist companions sometimes marveled at my ignorance of things American, and I still remember Jenkins's laugh when I told him that to inform myself about America, I had read Defoe's Moll Flanders. From it, however, I had learned that Quakers like himself were good, kind people. He and his wife liked to tease us when we could not understand New Yorker cartoons they showed us. On the other hand, he was very surprised when I pointed out to him that if there were counties, one expected to find also counts. He had never thought of the connection between the two.

Jenkins, Brode, and Allison, all three of them children of professors, were much more cultivated than Lawrence and some of our other colleagues, and they were also better-natured and more easygoing. The Jenkinses remained our best and closest American friends until their sad, early deaths. We often visited them informally in the evening, and their tales, example, and help with the problems of daily life contributed substantially both to our morale and to our adaptation to American customs.

Don Cooksey was another dear friend who valiantly helped us to adapt to America. He owned a ranch in Trinity County in northern California, not far from Forest Glen. One reached it after a walk of about forty-five minutes in a pine wood along the South Fork of the Trinity River. The ranch's log cabins were in a clearing near a small placer-mining operation. The cabins had been built around 1906 by a couple who had cared for Don, who was orphaned at an early age. These people had willed the cabin to their charge. The gold-mining claim had never been important in itself but helped in securing a deed from the Forest Service. A man who lived permanently at the camp with a couple of horses helped Don with the upkeep of the place. At the camp, one lived very simply, spending a good part of the time on or near the river. There was complete freedom: one could do nothing, read one of the interesting books stored in the cabin, swim, fish, float on an inner tube, walk around, or even, if one really wanted to, pan for gold. The trout fishing was good, and in the water one could see huge salmon that came to spawn in the river. The company was congenial: it consisted of the owners, and, in turn, Thornton, Kamen, McMillan, and several others connected with the Rad Lab. Whenever Cooksey's observant eye saw somebody in need of a restorative vacation, he invited him to his camp. There we were treated with exquisite courtesy, which we tried to reciprocate by helping with the necessary chores. Photographs show the kind of life we enjoyed. Such vacations made deep impressions and left all those who had the good fortune to share them with pleasant memories.

Before Elfriede's arrival, Henriette Jenkins and I went looking for a furnished house to rent. We found one at 2532a Piedmont Ave. in Berkeley for forty-five dollars a month, and as soon as she saw it, Henriette urged me to take it. I signed the rental agreement at once. The house was a wooden cottage in a yard behind some larger homes. It had a kitchen, living room, a couple of bedrooms, and a small porch. The whole was in indifferent shape and old, but in a convenient location and sufficient for us, at least temporarily. There was enough furniture so that we could manage until our own arrived from Palermo. When it arrived, with some effort we fitted it in. The landlady was a widow who tried to be helpful and accommodating. With a little good will, we could even take in a guest; and in fact Felix Bloch came to stay with us when he was working at the cyclotron with Alvarez. He slept on the porch in his sleeping bag, and Claudio used to wake him up in the morning, calling in Italian: "Bloch! Lavora!" (Bloch! Work!). Amaldi too spent some time with us and happened to be with us when World War II started.

With an eighteen-month-old baby to take care of, Elfriede also had to learn what food to buy, and where; where to find clothes; how to get medical help if necessary; and how to cope with a thousand details of daily life that were different in the United States. Above all, in Italy we had had a maid and a nanny; here everything fell on Elfriede's shoulders. She soon learned how to cook excellently, something she had never done before. No wonder she acquired the nickname "Tuechtigona" (an italianized augmentative of the German tüchtig, able and hard-working), which she fully deserved on all counts. How strenuous and demanding all this was emerges from our correspondence with my parents, where one often finds hints of tiredness.

In the beginning we did not have a car, but university, Rad Lab, and shopping centers were all within a fifteen-minute walk from home, so we did not need one. I did the shopping and I knew that my carrying strength sufficed up to five dollars worth of groceries. In May 1939, we bought our first American car, and a few days later Elfriede got her driving license, increasing our mobility.

From the moment of our arrival, we had had an immediate and important problem: obtaining an immigration visa. My tourist visa was for six months, so it lapsed in January 1939. In order to change one's visa, it was necessary to go to a U.S. consul outside the United States, and the most convenient place seemed to be Mexicali in Mexico. Immigration restrictions were steadily increasing as Hitler exacerbated his persecutions and more people tried to flee Europe; there was no time to waste. I remembered Rasetti's instruction in the subtle and marvelous points of Section 4(d) of the immigration law then in force, but when I tried to obtain some help from a service in San Francisco that was supposed to help immigrants, I concluded that it was better to do everything myself (one of Fermi's fundamental rules).

I asked the good Dean Pegram of Columbia University for a letter of recommendation to the consul, and he wrote a masterpiece. I asked for help in Berkeley too, but with little success. The university officials I contacted were polite but seemed exceedingly scared by the idea of incurring (nonexistent) responsibilities and limited themselves to the minimum they could not deny. However, armed with Pegram's recommendation and with my knowledge of the law that fitted my case perfectly, I took a bus and in two days arrived at Mexicali. Elfriede and Claudio were already in Berkeley with a tourist visa, but they could not possibly come with me at the time, and I thought it better to make two trips to Mexicali rather than wait until we could all go together.

On November 16, 1938, I obtained the visa that solved my immigration problems, and in February 1939, we returned to Mexicali to exchange Elfriede and Claudio's tourist visa for an immigration one too. We hoped we would not have to produce Claudio, but the consul insisted on his presence. As soon as Claudio entered his office, however, he started crying and yelling loudly, and the consul, at a loss for what to do, said, "Take him away immediately," which we did. Thus, with two trips to Mexicali, we settled our immigrant status. Later I read in a newspaper that the consul at Mexicali had been convicted of selling visas!

On November 29, 1938, we celebrated our first American Thanksgiving, with Emo and Bloch as our guests. I thought that we had every reason for celebrating, and that we pretty well resembled the early colonists who had originated the custom. Fermi used to say, whenever somebody bragged about his Pilgrim ancestry, or when he heard about the Daughters of the American Revolution, that he and other newly arrived refugees were the true, new pilgrims, who understood and appreciated some American ideals better than the American-born. About the same time, I received the news of the departure of my Rimini cousins from Italy for Montevideo, in Uruguay.

On February 2, 1939, we celebrated my father's eightieth birthday. We had written to him in time.

On May 10, 1939, my brother Angelo arrived in New York with his wife and two children. At first he tried to work at Columbia University in his field, economic history, and initially he had some success at this. Subsequently, however, he quarreled with everybody and gave up teaching, devoting himself entirely to painting. He exhibited in New York and had a certain critical success, but no financial reward, and did not persist in trying to sell his work. Although I invited him repeatedly to visit us in California, he never budged from the East Coast.

Angelo lived on family money, administered by me, according to my father's policies. I was cautious in the use of this money. I thought it should first be at my parents' disposal if they wanted to emigrate, and this took precedence over everything else. Second, one had to consider emergencies that might occur at any moment. I thought my family and I should live on my earnings alone as long as we could do so without great sacrifices and without endangering our future.

As soon as Angelo arrived at New York, he started pestering me with demands that ran counter to my instructions and policy. I gave him a monthly allowance of $150; it was not much, but it should have sufficed under the circumstances; in emergencies, he could ask for more. Angelo greatly upset me by threatening to complain to our father. Fortunately, a trusted friend of the family was out of Italy for a business trip, and through him I was able to communicate with Papà, who let me know that he approved of my conduct. Later, when I started earning a little more at Los Alamos, I sent some money of my own to Angelo, whose son needed an operation. In thanks I received a letter from Angelo saying that he considered my gift restitution of funds I had wrongly appropriated.

In 1938 after I had worked at the Rad Lab for a few weeks, Lawrence asked me if I could extend my stay beyond the month of October, the date I had given him for my return to Palermo. The offer was a godsend, but I sensed that precipitous acceptance was not to my advantage. I thanked Lawrence profusely and asked for some time to answer. Lawrence then went to Alaska on vacation, and I began to fear that he might change his mind, and that by trying to be too smart, I had destroyed my chance. Fortunately, on his return Lawrence renewed the offer of a salary of $300 a month for six months. My title was to be "research associate," a nondescript qualification that could apply to persons at very different levels. It had, however, one definite connotation: it implied a temporary job and did not commit the university or the Rad Lab beyond the term of the contract. At Christmas we were invited to Lawrence's home for dinner; oddly enough, he took the opportunity of telling me on this occasion that the lab was short of money, and that if necessary he would ask me to return part of my salary.

In 1939, $300 a month was a good salary, and it got me out of the woods for some time, but after six months, in July 1939, Lawrence, who by then must have realized my situation, asked me if I could return to Palermo. I answered by telling him the truth, and he immediately interjected: "But then why should I pay you $300 per month? From now on I will give you $116." I was stunned, and even now, so many years afterward, I marvel at Lawrence's impulsiveness; he did not think for a second of the impression he conveyed. With a minimum of reflection and diplomacy, he could have saved his $184 a month without cutting a horrible figure in my eyes. However, although I have not forgotten his conduct, I now see it in a different light than I did then.

I did not know what the salaries of other members of the Rad Lab were at the time. It was I who, with $300 a month, was the exception, and salaries around $116 were not rare. If I had known this and how Lawrence behaved with Americans who were unemployed because of the depression, I might have viewed the episode somewhat differently. I was somewhat older and better established as a scientist than some excellent Americans were, but they too got meager salaries, although they had academic positions and guaranteed careers.

In any case, with a wife and a child, a salary of $116 was scant, but it was not totally impossible to live on it. With $200 a month I could make ends meet, sparingly, but without deprivation, and I could bring my salary to that level by using my private funds, the existence of which was known only to Elfriede and to my friend Emo, whose discretion was absolute.

Elfriede and I constantly thought of our faraway parents. We wrote at length and regularly, at least once a week. Neither transatlantic airmail nor usable telephone connections with Italy existed, but the mails were better organized then, and a letter did not take much longer to reach Italy than it does today. My mother and Elfriede wrote at greater length than my father and I did, but he added at least a few lines, sometimes insignificant, sometimes important, to every letter. Each side tried to reassure the other, so the letters sounded a little more optimistic than they should have, and definitely more optimistic than those I exchanged with my cousins in Uruguay. When I complained, as I sometimes did, about the precariousness of my position, my father insisted that there was only one way of improving it: do good physics. If I succeeded in this, recognition would not fail to come, and career problems would take care of themselves. The times demanded prudence in writing; my parents interspersed praises of the Duce and other phrases intended for the eyes of a possible Fascist censor in their letters, although I doubt they would have fooled him.

The letters mirror Italian Jewish life in those tragic years, as one by one the young people emigrated and the older generation were left increasingly alone. At the same time, to their credit, many good old friends appeared, seeking to comfort my parents with frequent visits: Rasetti and his mother; Amaldi; Ginetta Barresi; the Salvati family and others in Tivoli, among them both important citizens and humble people; Ada Rimini and other relatives; my cousin Renzo Ravenna, the mayor of Ferrara, who came to visit his aunt and uncle and his close friend Italo Balbo, in Rome for a meeting of the Fascist Gran Consiglio. The letters report a great variety of other news: marriages, births, deaths, the recipe for some cakes I liked, urgings to Elfriede not to overdo things and to get the rest she needed, encouragement to use family money, indirect news of Elfriede's parents, as well as of Bindo and Riccardo, and so on. There is even a report on an exchange of letters with E. O. Lawrence in which they congratulated him on his Nobel Prize and received a friendly answer. On July 6, 1940, my father writes: "I am eager to know your arrangements with Lawrence, but in any case I am happy if scientific concepts absolutely prevail, an opinion shared by M" (this sentence means that I should, if necessary, use family funds to support myself). On April 9, 1941, he comments on the friendliness of a Carabinieri officer who had come to withdraw my Fascist Party card. Other news: the U.S. consul, who had rented our Palermo apartment, is leaving. On May 7, 1941, my mother "is memorizing our letters" and father "is working to prevent idleness from wearing out his spirit."

Correspondence with Germany and with Elfriede's parents was much more difficult and dangerous, and thus is much less informative.

All regular communications stopped in December 1941, with the entry of the United States into the war.

At Berkeley I had realized that there was only one salvation: to do good physics. With that weapon I might perhaps save myself; without it, I would be thrown out without mercy. This simple estimate of the situation was supported by my father's advice and inspiration and by prudent, but well informed and extremely welcome, encouragement from Fermi. Fortunately, I did not lack ideas, and the Rad Lab, for all its defects, offered unique opportunities for experimentation.

Half a century later, I see that my personality did not allow me any other way of survival; someone else might have made an easier life for himself than I did by being less touchy, less proud, more able to dissimulate, better at public relations, and simultaneously less timid and and less critical. I have by now attained some slight knowledge of myself, and I know how unpleasant I can be. However, if I am a curmudgeon, I have paid for it.

The 60-inch cyclotron was under construction; the magnet was there, but not much else yet. The sight of such a big, powerful magnet suggested to me the possibility of improving on my previous studies of the quadratic Zeeman effect. Jenkins was a spectroscopist, and we collaborated in this work.[12] Such research continues today because with bigger magnetic fields and much better spectroscopic resources, physicists keep finding new interesting details. The subject is now part of the study of what today are called Rydberg atoms.

In January 1939, having clearly understood the relation between nuclear isomerism and conversion electrons, it occurred to me that it might be possible to separate nuclear isomers with a method similar to that devised by Szilard and T. A. Chalmers for isolating products of the (n,g) reaction. I communicated my idea to Seaborg and told him that I needed a chemist who could synthesize a suitable organic molecule containing Br80. Seaborg found me Ralph Halford, who knew how to prepare a suitable organic bromine compound. We imprudently spoke of our project at the Faculty Club in the presence of Willard Libby, later famous for his carbon dating (I have been told that the suggestion came from Fermi in a Chicago seminar). At the time Libby was Seaborg's great rival and an assistant professor, while Seaborg was slightly his junior. Without telling anybody, Libby went to his lab and applied my method to tellurium isomers. He then wrote a letter describing the result to the Physical Review and was about to send it, when Seaborg got wind of the fact. A row developed, and I asked Libby to wait twenty-four hours before sending his letter, so as to allow us to finish our work, which was half done. Under strong pressure, Libby acquiesced, and the two letters to the Physical Review thus appeared side by side.[13]

It was an unusual experience for me. I do not think that Libby would have gotten away with such behavior in Europe at the time, certainly not in Rome. Criteria of intellectual property were more elastic in America; on the other hand, at least at the Rad Lab, there was great generosity in the exchange of instruments. It is difficult to pass judgment. Subsequently several Berkeley radiochemists, including Joseph Kennedy and Seaborg, eagerly pursued this method for separating radioactive isomers.

At the end of 1938, there were great hopes in Berkeley that Lawrence would win the Nobel Prize. I thought that if it did not go to Otto Stern or somebody older, it would go to Fermi. (The year before in Palermo, to my great surprise, I had received a nomination form, and I had nominated him.) I did not, of course, know that Bohr had confidentially told Fermi that he would be chosen that year if he wanted to be, or that Fermi was preparing to emigrate. When the official news that the physics prize for 1938 had been awarded to Fermi arrived, I was delighted and wrote to congratulate him, adding: "The only sadness is the thought of the various people of the old guard who would have rejoiced to be near you now that the reward of so much work, so many hours of labor, as well as c.i.f. (con intuito formidabile, 'with formidable intuition,' a joking acronym we used for statements by Fermi that were true, but that he could not prove), is here, and they are prevented by an inscrutable destiny." Lawrence acted with good grace, but he was clearly disappointed. He asked me whether I thought he would get the prize next year. I said I did, and this indeed came to pass. By chance, on November 14, 1939, the day of the announcement of Lawrence's prize, he was having dinner at our house.

At the beginning of 1939, the news of the discovery of fission by Otto Hahn and Fritz Strassmann reached Berkeley. The experiments were immediately repeated, but not by me. I did not like to rush into a competition, and although I had been among the first to work on uranium, I continued my investigations on other subjects. On my arrival in 1938 I had renewed my conversations of 1936 with Philip Abelson, who clearly indicated that he considered uranium his property, not troubling to hide his feelings about foreign interlopers. I therefore left uranium to him until the discovery of fission. Abelson then recognized that he had seen X-ray lines belonging to the tellurium K-series, but had misinterpreted them, a rather crude error, by which he missed making a great discovery. However, uranium also fooled Fermi, the Joliot-Curies, Hahn and Meitner, and other eminent scientists, all of whom made gross errors, and my own mistakes on the subject stand out. If Abelson had reason to be angry with himself, some time later I did too.

After the discovery of fission, Joliot-Curie and McMillan independently devised a clever physical method for separating the fission products from the product of the (n,b) reaction occurring in uranium. As a result of bombardment of a thin uranium layer, the fission fragments emerge from the layer and can be collected on a suitable adjacent foil, while the products of the (n,b) reaction stay in the uranium foil. It was thus possible to confirm Hahn and Meitner's finding of a 23-minute activity due to U239. In addition the uranium layer showed an activity, with about a 2-day period, and I started studying it chemically. I suspected it was a beta-decay product of the 23-minute activity and hence an isotope of element 93 (neptunium) of mass 239, but I did not expect that element 93 might be chemically similar to a rare earth. Everybody up to then believed that element 93 would be similar to rhenium, and this was one of the errors that had produced great confusion in the interpretation of all the results of uranium bombardment. I established chemically that the activity I was studying behaved similarly to a rare earth and then convinced myself that a fission fragment constituted by a heavy rare earth might stay in the uranium layer. I discussed this with Felix Bloch, who concurred, but the responsibility for the error is totally mine. On second thoughts, I should have realized that my interpretation was, to say the least, suspect.

I tried to make a stronger sample and to see whether the 2-day activity could be interpreted as the radioactive daughter of the 23-minute activity. In this I had bad luck. The ionization chamber I used had a window too thick for the beta rays of Np239, which are unusually weak. Furthermore, I went to the movies at a critical time when I should have been in the lab measuring the activity, although this fact was not of paramount importance.

In conclusion, I erred and did not recognize the genetic relation between the two activities. The resulting paper is fundamentally wrong, but it contains an important truth: the similarity between element 93 and the rare earths.[14] This similarity had even been considered in the literature, but the relevant papers had escaped me, and not only me. Shortly afterward, the problem of the 2-day activity was cracked by McMillan and Abelson, who discovered neptunium. After their discovery, in a letter home, dated June 4, 1940, I observed:

I do not know whether I have ever written to you of my misadventure with element 93. After so much work, discoveries and undiscoveries, last spring I had it in my hands for several weeks and did not recognize it. On the contrary I have even published a short note affirming that the substance they have now proved to be element 93 was a rare earth. Altogether it is an ugly blunder, combined with my having lost, in a most stupid way, the opportunity for a rather interesting discovery. Now there is nothing else I can do about it. Let us hope that the thing will not be proclaimed to all comers by my friends.

In other studies on fission products with Alex Langsdorf and Chien-Shiung Wu, we inter alia found Xe135, which is a tremendous neutron absorber. This last fact was discovered only later, when xenon poisoned the first nuclear reactors.[15]

In spite of my scientific activity, Lawrence must have come to the conclusion that I was too expensive. I contributed to the exploitation of his machine, but not sufficiently to its development or operation. Hence I could not aspire to a permanent position at Berkeley. Lawrence told me all this very forthrightly in December 1939 and demanded that I use at least half of my time in the service of the Rad Lab, probably intending the cyclotron. I may have believed that I was already using all my time for the benefit of the lab. He also urged me to find a job elsewhere and suggested I try an oil-prospecting company in Tulsa, Oklahoma. "In industry they are no great shakes and you will pass for a good physicist," he added. So saying, he wrote me an excellent recommendation. Lawrence's intentions may have been good, but his diplomacy was not. Remembering also the salary cut I had suffered, I reluctantly started thinking of leaving Berkeley.

I remembered, however, how my dear friend George Placzek consoled himself for having passed from the state of a wealthy gentleman to his present penury: "See! I am at Cornell University. I have an excellent salary: $1,000 a month, but expenses kill me!" He then listed imaginary expenses: $150 a month for having escaped the Nazis; $150 for living in a good climate; $100 for the use of the library and for having access to seminars and to worthy colleagues, and so forth. "I am left with only $120 per month, but it could be worse," Placzek concluded.[16]

By attending meetings, writing letters, passing the word around, and so on, I strove to find a more stable place than the one I held at Berkeley. Some of the answers were friendly, but some were chilling, like that of S. K. Allison, who pointed out to me that not even his student Skaggs (a completely unknown character) had found a job. The idea that I came after Skaggs in the mind of so knowledgeable a friend and gentleman as Allison scared me. Among the encouraging and friendly letters I received, I remember one from James Franck, the great experimental physicist of Göttingen, who had been dismissed by the Nazis and was then working at Chicago. Since Franck was a major figure in physics and was also known for his good heart (besides his courage), I expect he received many appeals for help. I wrote him and he answered with a solicitous and encouraging letter dated September 1, 1939. Finding insufficient what he had dictated to his secretary in English, he added by hand in German, "In your case I am truly optimistic, because people do not let slip a man of your ability." The encouragement of such a person helped me. Later Franck visited us in Berkeley and I met him many times in subsequent years, the last time at a meeting of Nobel laureates in Lindau, Germany, in 1962.

I also tried to mobilize Fermi's help, but I had the impression he was unwilling to bestir himself on my behalf. I now believe his unconcern was more apparent than real, because he preferred to appear indifferent rather than to say that he could not do much. More important, I believe that seeing me doing good work at Berkeley, he reasoned, like my father, that my position in Berkeley was undoubtedly scientifically most advantageous, and that it would be an error to exchange it for a permanent job in a minor university.

Few machines were to be as productive of important discoveries in nuclear physics as the 60-inch cyclotron, which started working at the beginning of 1940. I immediately suggested that since it could accelerate alpha particles enough for them to penetrate potential barriers of heavy elements, one could form isotopes of the missing element 85 by bombarding bismuth with alpha particles. Robert Cornog has described what followed:

One Monday night at a meeting of the Radiation Laboratory group, Emilio Segrè described his plans to make element 85 by bombarding bismuth with alpha-particles accelerated in the 60-inch cyclotron. After the meeting, as Dale Corson and I walked together across campus, we talked of Segrè's proposed experiment. Unaware that Corson was already preparing to do some alpha-particle bombardments with the 60-inch cyclotron, I said: "You know, Dale, I have a lump of bismuth." "And I have a linear amplifier," Dale countered.

The next morning, bright and early, Corson and I bombarded bismuth with alpha-particles from the 60-inch cyclotron. We saw gobs of giant pulses when we placed the bismuth in front of our linear amplifier. I was elated but felt guilty as sin to have poached what I felt was Segrè's experiment, so I went directly to see Segrè. "Emilio, would you mind much if I had a try at that bismuth experiment you described last night?" I asked. After a short pause Segrè replied: "No. There are other experiments that I can do." Now came the sticky part. "It's worse than that, Emilio. Dale Corson and I have already bombarded bismuth. We got giant pulses on his linear amplifier." Segrè paused somewhat longer. "I have only one request. Let me do the chemistry."

It was a day or two after these events that Luie [Alvarez] was especially articulate and direct. He suggested that I work either on discovering element 85 or on discovering the stability of hydrogen-3 and helium-3, but not on both! So Corson, MacKenzie and Segrè discovered element 85 and Alvarez and Cornog discovered hydrogen and helium of mass 3. All these events notwithstanding, Segrè continued to let me use his electrometer, an instrument which now resides in the Smithsonian collection.[17]

Today, as we proposed, element 85, the last of the halogens, is called astatine. As in the case of the other halogens, the name refers to one of its outstanding properties: its instability. Astatine chemistry is complicated, and as all its isotopes are short-lived, it can be studied only on the tracer scale. Chien-Shiung Wu and I also tried to form the last cisuranic missing element, of atomic number 61, by suitable bombardment of rare earths, but at the time the chemical separation of rare earths presented difficult problems, subsequently overcome by elution on resins. We certainly produced isotopes of element 61, but we could not prove it to our satisfaction, and the element was later discovered by Glendenin and Marinsky.

From January 30 to February 20, 1940, Fermi came to Berkeley as Hitchcock Lecturer. I was delighted to see him (it was the first time we had met since leaving Italy), and we resumed our habit of taking long walks together, talking mostly physics. Fermi explained to me his latest studies on the stopping power for ionizing particles and on its relativistic rise. We tried to verify some of his predictions experimentally using the electrons of P32 , but the results were inconclusive. On the other hand, with the new 60-inch cyclotron we fissioned uranium with alpha particles, reporting our findings in the last paper we coauthored (although certainly not the last we discussed in the planning stage or to interpret results).[18] At that time Fermi did not mention his studies of the chain reaction to me. As I have emphasized, he was always reserved, and in this case he had weighty reasons for being more than merely cautious.

As was to be expected, Fermi often spoke to Lawrence, but when he started talking physics, Lawrence usually changed the subject, possibly because it was uncomfortable for him. Fermi doubted Lawrence knew or understood much physics, and thought he was rather full of himself. "It's a real problem when people must play the great man but are not up to it," he said. Fermi also attended Oppenheimer's seminars; coming out of one of them once, he said: "Emilio, I must be getting senile. I went to a learned theoretical seminar and could not understand anything except the last words, which were 'And this is Fermi's theory of beta decay.'"

Some of the conversations I had with Fermi concerned beta decay and its ramifications, and it occurred to me that it might be possible to alter the decay constant of a K-electron capturer by chemical means. Since the decay constant is proportional to the electronic density at the nucleus, by subtracting electrons from an atom, it should be possible to alter that density. I estimated the effect and found out that it would be small but probably observable. The best substance to try was Be7, because of its atomic and nuclear characteristics. On second thoughts, I also concluded that the same mechanism should alter the internal conversion and, as a consequence, the decay periods of my old friends the nuclear isomers. Generally the technique opened up a small chapter of nuclear physics, on altering nuclear processes by chemical means. This had been tried by simple-minded methods by the founders of nuclear physics, but since they lacked the necessary insight, their results had always been negative.

In pursuit of this idea, Chien-Shiung Wu and I tried preparing radioactive BeO and asked the Brush Beryllium Co. to convert some of it to metal. However, after a while more urgent work forced us to drop the project for the duration of the war. I did not publish anything on the subject then, because I disliked publishing ideas of experiments without having performed them. It was most fortunate that we suspended the work, because we did not know of the toxicity of beryllium and would unwittingly have incurred deadly dangers. After the war I completed the investigation with C. E. Wiegand, who was then my student.[19]

In 1940 Lawrence was planning a 184-inch cyclotron to reach the then-enormous energy of 100 MeV. Lawrence expected to overcome relativistic difficulties by putting a million volts on the dees and reaching the final energy in only fifty revolutions. It was a typical brute force method, which might have pleased Admiral Farragut of "Damn the torpedoes—full speed ahead!" fame, but I do not know if it would have succeeded. Lawrence was convinced that with enthusiasm, hard work, and persistence one could overcome every obstacle, or that somebody would find a way out by a new invention, as indeed occasionally happened, particularly in this case. However, ingenuity may circumvent nature's laws, but not violate them.

I realized that if I were to survive at the Rad Lab, I had better contribute to the great 184-inch cyclotron project, so when asked, I eagerly started helping William Brobeck, the exceptionally able engineer who headed the project. Brobeck was a rich young man, the son of a prominent San Francisco lawyer, and in love with his profession. He had a profoundly salutary influence on the Rad Lab because he introduced sound engineering practice in place of the physicists' roughand-ready way of doing things. Machines were planned with reasonable safety margins, and good engineering techniques replaced improvisation. Due attention was paid to gaskets, welding, stress distribution, and choice of materials. Brobeck introduced all sorts of important preventive maintenance routines. In short, he injected the art of engineering into accelerator development. As a consequence the functioning of the machines greatly improved, the wasting of time owing to breakdowns markedly diminished, and overall efficiency increased substantially. Brobeck was highly respected by the ablest physicists, who understood that his demands were well-founded and abundantly repaid the work and expense of complying with them. From 1937 until 1956, when he left the Rad Lab, Brobeck was involved in all its projects.

In 1940 Brobeck was planning the 184-inch cyclotron magnet, and I helped him in the building and testing of a model of it. In the beginning, it seems, Brobeck had a certain diffidence about working with a foreign physicist, unfamiliar with American engineering units and methods. However, we very rapidly found ourselves to be congenial and greatly enjoying the collaboration. Each learned from the other. I was pleasantly surprised in finding that Brobeck had advertised my work to Lawrence, who was impressed, since the praise came from an unexpected source. A letter home of May 22, 1940, says I was working full-time on the magnet.

At t

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Chapter Five—On My Own: Professor at Palermo (1936–1938):
Scent of Orange Blossoms

Non sien le genti, ancor, troppo sicure
a giudicar, sì come quei che stima
le biade in campo pria che sien mature;
ch'i' ho veduto tutto 'l verno prima
lo prun mostrarsi rigido e feroce;
poscia portar la rosa in su la cima;
e legno vidi già dritto e veloce,
correr lo mar per tutto suo cammino,
perire al fine a l'intrar de la foce.

(Let not the people be too self-assured
In judging early, as who should count the rows
Of green blades in the field ere they matured.
For I have seen how first the wild-brier shows
Her sprays, all winter through, thorny and stark,
And then upon the topmost bears the rose;
And I have seen ere now a speeding barque
Run all her sea-course with unswerving stem
And close on harbour go down to the dark.)
Dante, Paradiso 13.130–38 (trans. Laurence Binyon)

Marriage and transfer to Palermo signaled significant changes in my life. From being a young man living in his parents' home, I now became the head of a new family; from being a subordinate in the Physics Institute in Rome, I became chief of an institute of my own in Sicily. At the University of Palermo I was a young, but important, tenured professor, and my career seemed established, inasmuch according to the Italian law then prevailing, further advancement occurred mostly by seniority. I wanted to give the best of myself. I hoped to set an example of renewal and modernization in teaching and also to initiate some meaningful research in a new Italian center. I felt liberated from the need to write papers for my advancement; only science counted. Similarly, our new family would be ours alone; I loved my parents and tradition, but the family Elfriede and I established would differ from theirs in many ways.

At the beginning of my stay in Palermo, I lodged in the Pensione Lincoln, on Via Archirafi, near the Physics Institute. The pension was comfortable in its simplicity. The institute was located in a new building, with very large rooms and much wasted space. The existing apparatus dated from the nineteenth century. To offset this, there was a bronze head of Professor La Rosa, my predecessor. The personnel consisted of a middle-aged assistant, who seemed to me unretrievable for useful work, an old mechanic, competent within his limitations and full of good will, and some more than adequate janitors.

On the floor above the Physics Institute, occupying territory that in theory belonged to physics, was the Mineralogy Institute. Since I did not need more space, there was no conflict. On the contrary, the professor of mineralogy, Carlo Perrier (1886–1948) was a nice fellow, a true Piedmontese gentleman, and an anti-Fascist.[1] He was a bachelor, about twenty years older than I, and well versed in classical mineralogy and analytical chemistry. Soon we became close friends, and this friendship later brought its fruits. He also efficiently guided me through the shoals of Palermo's university politics.

My first priority was to organize the important service courses for engineers; my second, to provide instruction on more advanced physics (fisica superiore), which had also been entrusted to me; my third, to start some research.

I amused myself by inspecting old teaching apparatus, as I had done in Rome once with Amaldi when we were still students. At that time, we had discovered several pieces of equipment dating from the second half of the nineteenth century, among them a gadget for demonstrating conical refraction, which required some thought before we could figure out what it was. At Palermo I found pieces going back to the times of Augusto Righi, Damiano Macaluso, O. M. Corbino, and other of my predecessors. The library was devoid of modern books and journals. On the other hand, I had a beautiful office with elegant furniture, and a letterhead that possibly went back to King Umberto I (assassinated in 1900), which I enjoyed using. For the rest, the Physics Institute was a desert.

At the first faculty meeting, with about a dozen professors sitting around a table, I could see that there were no big fights afoot. The mathematicians Michele de Franchis and Michele Cipolla were authorities in their fields. The botanist Montemartini was confined to Palermo because he was notoriously anti-Fascist, and the zoologist Giardina, although now very old, had once been brilliant. The chemists did not seem exactly at the level of their great predecessor, Stanislao Cannizzaro, and neither did the astronomer appear to be the equal of his great predecessor, Giuseppe Piazzi. All were good professors, however, with whom it was easy to agree provided one maintained polite behavior and due respect for turf.

I clearly stated that I had no intention of being a bird of passage. I would do my best to improve physics and I would not spend day and night planning how to contrive a transfer, as many professors from the mainland used to do. When my Sicilian colleagues perceived that I truly meant what I said, they helped me in whatever ways they could and adopted me as one of them. Thus my university relations were excellent.

Palermo was not, in fact, one of the minor posts usually conferred at the start of a university career, such as Camerino, or Sassari, but neither was it one of the major seats in which one landed at the end of a meritorious career, such as Rome, Bologna, Pisa, or Turin. At Palermo there were a good many Sicilians, for whom it was the seat of choice; some notorious anti-Fascists, such as Perrier and Montemartini, who were not in the good graces of the minister and would not be transferred even if they wanted to be; and some young professors at the beginning of their careers.

As soon as possible after my return from America, I had joined Elfriede in Florence, and we started making detailed plans for our imminent wedding. Elfriede ordered linens for our home from the house of Pini in Florence. She bought an elegant dress at Zecca in Rome and stocked up on top-quality household items and clothing, destined to last a long time. This fitted our philosophy, as well as that of my parents. However, when the bills arrived, some were pretty stiff. Imprudently, my father or I (I do not remember who) made some comments on this. Elfriede immediately started crying; her bitter and unusual tears startled me even more because they showed a surprising misunderstanding. No criticism of her had been implied; on the contrary, everybody was satisfied that she had done very well.

Elfriede and I decided to marry on Sunday, February 2, 1936. To our great regret, Elfriede's parents could not come to the wedding, but they visited us later when we were settled in Palermo. I went to the Rome synagogue to make arrangements for the wedding ceremony and told the rabbi that I wanted the simplest and cheapest wedding available, the more so as the parents of the bride could not attend. The rabbi winced, and I added that I found it inappropriate to spend money on ceremonies when there were so many tragic situations that needed help. To dispel any doubts in his mind I added: "How much does a luxury wedding cost?" He told me, and I gave him the sum, saying that he should arrange the simplest possible ceremony for us, as I had requested, and spend the difference for German refugees. This was the agreement. On the day of the wedding, however, the Temple was full of flowers and tapestries with great pomp. The rabbi gave us a short homily. "See! Adonai. . . . Before yours, there was a luxury wedding ceremony and there was no time to change the decorations. Thus you too will have a luxury wedding." A reception at the old Hotel de Russie followed. It was attended by friends and relatives, including Corbino, Levi-Civita, and my physicist friends.

From Rome, in terrible weather, we went to the Hotel Vesuvio in Naples, and as the rain persisted, we went to visit my friend Carrelli, professor of physics at Naples, who showed us a splendid calcite crystal, a present of Fresnel to Melloni, from his museum. Bad luck had it that it slipped from Elfriede's hand and was chipped in one corner. Our embarrassment is hard to describe.

At Palermo we lodged at the Hotel Excelsior in Piazza della Libeftà. Papà had commanded me not to return to Pensione Lincoln but to find the best possible accommodation. The Excelsior was then an excellent hotel, with a first-class chef and an able manager, who was stuck in Palermo because he was suspected of anti-Fascism. He took a liking to us and treated us as his protégés, giving us the best rooms of the hotel and keeping them always at our disposal.

Before our departure from Rome, my father, unbeknown to me, had taken Elfriede aside and given her a small sum, telling her that she should use it for postage stamps to write to both families. The money would have sufficed for writing by special delivery all her life and more. Elfriede deeply appreciated the gesture.

This and similar episodes must be seen in relation to my wish to live within my professorial salary of about two thousand lire a month. My father, who was more practical, decided to add a substantial monthly supplement to my salary. When I refused to accept this, he instructed Bindo Rimini: "Go to your cousin and tell him he is not only a fool, but also rude." My father was quite right. The sum was trifling for him; it pleased him to give it to us, and it helped to make our life more pleasant. Furthermore, neither Elfriede nor I was lazy or spendthrift. After a while, I realized that instead of being haughty with my father, I should be grateful and thank him.

Immediately after our arrival in Palermo, we started exploring its surroundings. It was an exceptionally cold spell; there was even snow on some of the mountains, a most unusual condition. Later, however, we became fully acquainted with the extraordinary beauty of that part of Sicily.

On our first vacation, we decided to go on a true honeymoon trip, skiing in the Dolomites. At that time there were no ski lifts, and one climbed using sealskins; but we really enjoyed our avocation of crosscountry skiing. We went around the Sella group carrying our rucksacks and sleeping in small hotels or huts. In one of them, our room remained quite cold in spite of an electric heater. I examined it and changed the connections of its resistors from series to parallel, quadrupling the heat output. Elfriede admired the power of physics, but the next day the innkeeper made a scene because we had used too much power.

Finally, we returned to Palermo to stay for a longer period. We started by making an official round of visits to the dean and the rector, who was most cordial. The dean was not at home, but his wife was, and she received us in a friendly way. We noticed her conspicuous beautiful and brilliant red hair and began a polite social conversation. After suitable platitudes, she offered us some karkade, an infusion of an Ethiopian plant that in those times of sanctions by the League of Nations was supposed to replace tea. It was deep red and had a flavor new to us. Caught by surprise, we found it hardly drinkable. A look between us showed us that we had had the same thought: perhaps it was used to dye our hostess's hair.

No less than mine, Elfriede's life had changed radically with her marriage and coming to Palermo. She was no more "La Spiro," but Signora Segrè. However, we had not changed our fundamental habits of first working hard and then finding our recreation in the mountains or in touring. In the beginning we did not own a car, but we soon acquired one and drove it down from Rome to Palermo. I had thus repeated a good part of the itinerary I had covered with Rasetti in 1929, but we could not enter the Palazzo Cimbrone at Ravello because Greta Garbo and Leopold Stokowski had rented it and locked themselves up in it.

The Palermo of 1936 was a beautiful city; despite its location, it was not provincial. At the beginning of the century, it had enjoyed a great cultural and architectural flowering. It had shops comparable to those of the greatest Italian cities, an excellent opera house, and magnificent villas flanking the Viale della Libertà, not to mention the antiquities, Arab, Norman, and baroque, that testified to its millennial history. All told, one could recognize a capital, perhaps slightly Bourbon, of the Kingdom of the Two Sicilies. Surrounded by Monte Grifone, Monreale, Monte Pellegrino, and Mondello like precious stones set in a ring around a central diamond, the city offered splendid outings. In the spring we could smell the scent of orange blossoms, which became more pungent at sunset. War and uncontrolled population influx have ruined Palermo, as they have most Italian cities.

While very busy organizing the Physics Institute, I started teaching the elementary experimental physics course, performing many demonstrations with apparatus that had been out of use for perhaps fifty years. I also prepared a few instruments in the hope of being able to begin some research. As a start, I built one of our standard ionization chambers and ordered a Perucca-type electrometer and other equipment needed for radioactive work. I hoped somehow to secure long-lived radioactive isotopes for study. I asked my physicist friends to suggest names for a couple of vacant assistant professorships automatically placing former pupils of the Scuola normale at Pisa high on my list. I thus met B. N. Cacciapuoti and Manlio Mandò, whom I was subsequently able to hire. Years later, the one became a professor at Pisa, and the other, after a long period as a prisoner of war in India, at Florence; Mariano Santangelo, an able young student at Palermo, became professor at Modena.

Among the students was a young lady, Ginetta Barresi, related to the Crocco Family, famous in Italian aviation. She was an unusual person; most intelligent, with deep Sicilian roots, sincerely religious and learned in Catholic doctrine. In those days a woman physics student was a rarity, and in Palermo she was the only one. Ginetta had no qualms about the matter; she studied her chosen subject proficiently and if people wondered, she let them wonder. Her unusual culture extended to literary subjects and was always very solid and well digested, never superficial. She became our dear friend and helped us admirably in the difficult times that were to follow.

In keeping with tradition, I started writing lecture notes for my course in experimental physics. I completed and published the first volume,[2] and I started the second but could not finish it before my dismissal. For fisica superiore, I taught electricity. I introduced written examinations, a novelty in Italian universities. The attempt produced a certain ferment, but ultimately the students became resigned to this innovation, although it was dubious whether written examinations were legal. A typical question for such exams was: Calculate the weight of a mercury sphere of 3 cm radius. Unfortunately, the answers were not edifying.

Since the majority of physics students became high school teachers, I thought it would be useful to write a book on "elementary physics, from a higher point of view," modeled on the similar ones for mathematics, edited by Felix Klein in German and by Federigo Enriques in Italian. I worked seriously on the project, writing a detailed program for the work. It was to consist of a series of articles, and I looked for collaborators, and for a publisher. This last was to be Sansoni of Florence, who belonged to the Gentile family. The racial laws put an end to my endeavors, but Giovanni Gentile, Jr., continued the project until he died prematurely in 1942. After the war, Gilberto Bernardini resumed the initiative, and the first volume appeared in 1947. Bernardini's preface summarizes the history of the book. I believe that the idea has still some merit.[3]

In 1936 I could not yet assemble the minimum equipment necessary to start research at Palermo, but I took advantage of vacations to do some experiments in Rome. I found Amaldi and Fermi deeply engulfed in their fundamental investigations on the slowing down of neutrons in hydrogenous substances. I had the impression that they did not want to waste time even with an old friend like myself. I spoke to Wick, who was in Rome, and did something by myself with the instruments and sources available.

All told, the school year 1936 passed quickly and pleasantly. For the summer I thought of going to have a look at the United States with Elfriede. At the beginning of the summer, it turned out that she was pregnant, but since she had no complaints whatever, we decided to go anyway. Later, with a small child, it would be much more difficult to travel, hence this would be our last chance, at least for several years, to visit America. Moreover, we were disturbed by the steady downhill trend of events. Although we personally had prospered, we were convinced of the precariousness of the situation, and this was one more reason for keeping in contact with American physicists and for showing up in the United States.

For me, the natural place to visit was Columbia University; I had been there before, had rapidly done good work there, and had struck up a friendship with the Columbia neutron physicists. I knew their instruments, and we had common scientific interests. I thus wrote to Dean Pegram proposing to go there, and on July 2, 1936, we landed in New York. Amaldi, too, came to New York in the same period.

We had not, however, reckoned with New York's hot, humid weather and with the suffering it would bring to a pregnant woman. Elfriede could not sleep well for the heat; she got up at night to take showers to cool off; it was clear that the heat was not only unpleasant but unhealthy. Thus, as soon as possible, we departed for better climates.

Otto Stern had extolled the future of Ernest Lawrence's cyclotron to us in previous years. In 1935, when we were in Ann Arbor, Fermi and I had corresponded with Lawrence. At that time, I do not remember for what reason, he offered Fermi a millicurie of radiosodium. Doubting Berkeley's radioactivity measurements, Fermi replied suggesting that Lawrence had perhaps made a mistake and actually meant a microcurie, a thousand times less. In answer, he received a letter containing a millicurie of radiosodium. We were dumbfounded. By then I was sure I wanted to go to see the cyclotron. Later, when I knew the Radiation Laboratory from the inside, I could imagine the effect that Fermi's letter must have produced and Lawrence's reaction.

At Rome we had discussed the possibility of building such a machine, and we had even tried to locate a magnet similar to the one used for the 37-inch cyclotron in Berkeley (Marconi had used it in the radio station at Coltano many years earlier; in fact, I believe it was the one I had seen there as a child before World War I). Ultimately, however, the plan came to naught, and in 1936, cyclotron and climate attracted me to Berkeley.

We left New York by train and stopped for a few days in Ann Arbor, Michigan, where Elfriede started feeling better; then we crossed the continent on a famous train called "The Challenger," reaching Berkeley in three days. We had two objectives: learning about the cyclotron and visiting California and the West. We rented a Ford car for one month, hoping that it would also serve Elfriede to learn to drive. I then plunged into the Radiation Laboratory for several days.

Lawrence was most cordial.[4] It was my first meeting with him and I was not used to his personality, so different from that of any other physicist I knew. He invited us to his home for dinner, where I ate avocado for the first time. (I did not like it then, but I do now.)

Besides Lawrence, I spoke with Edwin McMillan,[5] Don Cooksey, Franz Kurie, Philip Abelson,[6] and others I do not remember. J. Robert Oppenheimer also invited us for dinner.[7] I gave a couple of lectures on neutrons and made a detailed tour of the Rad Lab, speaking extensively with Abelson, then a graduate student working on uranium. I told him that there was undoubtedly a mystery in uranium bombarded by neutrons. With a source as powerful as the cyclotron, the Berkeley researchers had the inestimable advantage of being able to generate an activity that was large compared with the natural activity of uranium. This should enable them to see things hidden from everybody else. As a first step, I proposed they see whether there was a difference between the activity produced by fast and slow neutrons. Of course, I had no idea of the nature of the mystery presented by uranium, but I knew it was there. Abelson worked a little on the subject and gave me the decay curves he obtained, but at the time he went no further.

I also renewed my acquaintance with Count Lorenzo Emo Capodilista. I had known him since his student days in Florence, where he had worked with the local cosmic-ray group. He had lost his mother when still very young and cherished his wealthy grandmother, a Mrs. Parrish of Philadelphia, who was a true lady, remarkable for her vigor, intelligence, and imposing appearance. Lorenzo had a heart of gold and was a wise man and a true gentleman, but not a rabid physicist like most of his colleagues. Possessing independent means and extended interests beyond physics, he tended to enjoy life. Elfriede liked him at once, too, and he later became one of our closest friends.

In visiting the Rad Lab, I noticed that there was a lot of radioactive metal scrap lying around. Nobody knew what it contained. I asked for some samples to take with me to Palermo. The radioactivities undoubtedly had long periods, and I would be able to study them at leisure upon my return. With luck, there might be something interesting. I took several pieces of metal that had belonged to cyclotron parts. Lawrence was very kind and generous in giving me this material; he said he was happy I could use it and glad to be able to help so penurious a place as Palermo.

When I had concluded my scientific visits, Elfriede and I drove off to see the marvels of the West. We were convinced that this was a unique opportunity to do so, and some fifty years in fact elapsed before I returned to some of the places we visited. Other places, on the contrary, became frequent destinations when we settled in Berkeley.

Rasetti, as usual, had lectured us on the places we must see, and his guidance from afar was very useful to us. We went to Yosemite and Death Valley, continuing to some truly wild deserts in Navajo country, but missed the Canyon de Chelly, which Rasetti had rated a must. We visited Boulder Dam still half empty, and the Utah national parks, bought cactus seeds for Montemartini and Palermo's botanical garden, and went to Mount Wilson Observatory and to the movie studios in Hollywood. Happy with our trip, we returned to Berkeley, where I collected my radioactive material. On October 10th, 1936, we landed in Naples.

On my return to Palermo I immediately started work on the material I had obtained in Berkeley. The instruments I had prepared the previous year were perfectly suited to my program; furthermore, I had built a chemical hood and had found glassware and chemical instruments in the lab, which perhaps went back to the time of Cannizzaro. I was thus able to start chemical separations using the usual radiochemistry techniques.

I soon discovered that I had taken with me a true mine of radioactive substances. The cyclotron had been used for bombarding a little of everything, although mainly phosphorus; no special precautions had been taken, so I found many different substances that had vaporized from the target. In addition to phosphorus, a preliminary survey revealed radioactive cobalt, zinc, perhaps silver, and other activities I could not ascribe to any known element.

I first recognized a large quantity of P32, with a half life of about two weeks. I thought immediately that this might be useful for biological experiments, but naturally, not being a biologist, I did not know specifically what to do with it. I explained the tracer technique, then relatively new, in detail to my colleague Camillo Artom, professor of physiology, and offered him the radioactive phosphorus and the necessary technical help with radioactive measurements. Artom at once grasped the technique and the possibilities it offered, and immediately thought of some interesting applications to phospholipid metabolism. Thus began a fruitful collaboration, which produced good results. Having learned a minimum of physiology and biochemistry, I tried to make a rudimentary mathematical model of a mouse, describing its metabolism by suitable coefficients. Some of the ideas went back to Volterra's old studies, which I had read as a student.[8] I believe that this type of investigation, greatly refined and expanded, has developed into a fashionable endeavor.

In February 1937 I received a letter from Lawrence containing more radioactive stuff. In particular, it contained a molybdenum foil that had been part of the cyclotron's deflector. I suspected at once that it might contain element 43.[9] The simple reason was that deuteron bombardment of molybdenum (atomic number 42) should give isotopes of element 43 through well-established nuclear reactions. My sample, the molybdenum deflector lip, had certainly been intensely bombarded with deuterons, and I noted that one of its faces was much more radioactive than the other. I then dissolved only the material of the active face, in this way achieving a first important concentration of the activity.

By now I was more sophisticated than I had been in Rome in 1934, and I knew that the "masurium" announced by I. W. and W. K. Noddack in 1925 was probably a mistake. Among other reasons, nuclear systematics raised strong suspicions about its stability. I thus had to prove that I really had in hand a new element, created artificially and devoid of stable isotopes. The methods for such an investigation had been pioneered long ago by D. I. Mendeleyev and Marie Curie. One predicts the chemical properties to be expected for the new substance by criteria similar to those used by Mendeleyev, and then one tries to verify the predictions by radiochemical methods, taking into account that the behavior of trace amounts of a substance can be different from that of matter in bulk.

For this investigation I enlisted the cooperation of Carlo Perrier, who had more experience in chemistry than I. First we separated the activity we were studying from all known elements to make sure that it was not isotopic with any of them. Next we established several of the chemical properties of element 43. Separation from rhenium was the most difficult problem, but in the end we succeeded in two different ways: by precipitation as a sulfide in a very acid solution and by distillation in a current of gaseous hydrochloric acid. All this work was most amusing and of obvious importance.[10]

By following the radioactive decay of our samples and by measuring the absorption in aluminum of the electrons emitted, B. N. Cacciapuoti and I found three decay periods: 90, 80, and 50 days. Looking back on the data fifty years later, I see that in effect we had only two radioactive isotopes: technetium 95, with a period of 61 days, and technetium 97, with a period of 90 days. They are both nuclear isomeric states with complex electronic radiations, obtained by deuteron bombardment of several molybdenum isotopes.

In this work we had discovered the first chemical element created by man.[11] Perrier and I decided not to name the new element at the time, although we received suggestions for names celebrating Fascism or Sicily, such as Trinacrium (from Trinacria, an ancient Greek name for the island), which we did not like. Moreover, for us to avoid controversy with Walter Noddack and Ida Tacke-Noddack, they first had to retract their claims, or these had to fall of their own weight, as later happened. We also knew that many more elements had been named or announced than truly existed. Haste in naming did not seem like good style to us.[12]

Georg von Heresy, who knew the Noddacks' work at first hand, wrote to me explaining its weaknesses. Heresy, a Hungarian educated with all refinements of the old Austrian Empire, was one of the greatest living chemists and a close friend of Niels Bohr. He and Fritz Paneth had invented the radioactive tracer method, and Hevesy and Dirk Coster had discovered the element hafnium, using X-rays as an analytical tool.[13]

The Noddacks were chemists, highly respected for their discovery of rhenium, which they detected in several ores in 1925. In the same paper they had announced the discovery of two elements: element 75, which they named rhenium (from Rhenus, the ancient name for the Rhine), and element 43, which they named masurium (from Masuria, the easternmost part of East Prussia, where German armies had repeatedly defeated the Russians in World War I). Rhenium was soon confirmed, and the Noddacks prepared it in macroscopic amounts, but they did not make any further mention of masurium. In 1933, when I bought all the elements available in Rome for our neutron work, I found a sample of rhenium, but not one of masurium.

In 1937, after receiving the letter from Hevesy mentioned above, I had some doubts about the Noddacks' results and decided to visit them and to obtain firsthand information on their work. About September 20, on my return from Copenhagen (see p. 122), I stopped in Freiburg, where the Noddacks had their lab. Professor Walter Noddack kept me waiting for a while, but ultimately he received me. I did not see his wife.

I showed Noddack the proofs of our Lincei paper giving the properties of element 43 and asked him whether his results agreed with ours. "Yes," was the answer. I asked him whether he had found something on the chemistry of 43 beyond what we had, and he said, "No." I asked him how much masurium they had, and he answered about 1 mg, which to me seemed unlikely. He told me he had sent it to Francis Aston at the Cavendish Laboratory for isotopic analysis, which surprised me. I asked to see some of his X-ray plates, with the characteristic spectrum of 43. He answered that unfortunately the plates had accidentally been broken and hence were not available. When I asked why he had not made more plates, I could not obtain a clear answer. By then I was thinking that either they were deluding themselves or they had doubts about their results and hoped that further work might resolve them; in the meantime they did not want to prejudice the issue. In any case it was unlikely that they had clear-cut results. Having formed this opinion, I took my leave.

I was surprised when a couple of weeks later Noddack, his wife (if I remember correctly), and a cohort of assistants showed up at my lab in Palermo. I showed them what we had. These are the only personal contacts I remember having had with the Noddacks.

After the war, when nuclear reactors produced macroscopic amounts of element 43, I had the satisfaction of seeing, not only that we had made no mistakes, but also that we had found the main properties of the new substance. Only then did Perrier and I give it the name technetium to commemorate the fact that it was the first artificial element.[14]

One day Fermi came to visit me at Palermo and told me he thought our work on element 43 was the best piece of work in physics in the preceding year. Since Fermi did not make such statements merely to please, or without due consideration, I was elated.

The prime necessity for further work was the supply of radioactive substances. I asked Lorenzo Emo to send me more material from Berkeley, which he did, with Lawrence's permission. When I received a letter from Berkeley, I measured its radioactivity before opening it. I also sent to Berkeley a collection of test tubes containing several substances to be put near the cyclotron target where they would be neutron irradiated. Among them I included some purified uranium and thorium, because I was aware of the uranium mysteries, some ammonium nitrate, in the hope of finding C14 , and sundry other materials. The cyclotron produced so many neutrons that if my samples were simply kept in a box near the target, I could obtain precious material that would keep me busy for quite a while; or at least I so hoped.

The beginning of the year 1937 was darkened by an unexpected tragedy. Corbino caught pneumonia and died in a few days, on January 23. His death was a severe blow. He was only sixty-one, and we had all counted on his wise counsel and guidance in the difficult times we anticipated.

I immediately saw what the consequences of Corbino's death would be, and I was soon proved right. When I went to Rome for the funeral, I found that his post, which should logically have gone to Fermi, had become the target of obscure cabals. The end result was Lo Surdo's appointment as director of the Physics Institute. I could not have imagined a worse choice. Among other things it ensured hostility, in place of benevolence, toward Fermi's group, which, in my opinion, was exerting a most salutary influence on Italian physics.

Another surprise followed shortly after: Amaldi was appointed professor at Rome. He had competed successfully for a chair at Cagliari, in Sardinia, but had renounced the appointment in order not to have to leave Rome. Immediately afterward, he was called to the University of Rome. The whole deal had very negative implications for me. I came from the same stable as Amaldi, had been first assistant to Corbino, and had seniority over Amaldi; nor could it be said that his scientific work overshadowed mine. Obviously my chances of returning to Rome and rejoining the group were vanishing. Amaldi's appointment at Rome also meant that Fermi and Rasetti either could not or did not want to put up a fight for me. Fermi, as a matter of principle, avoided losing battles, and the whole development signaled to me that my chances of being appointed to a better chair than Palermo were slim indeed. Although the idea of remaining at Palermo for a long time was not disagreeable per se, I was concerned for the future of my research. It was not easy for me to imagine how I would be able to continue to do interesting work in Sicily. Ultimately, however, Amaldi's appointment did me little harm and turned out to be a stroke of good luck for Italian physics.[15]

Having assessed the situation at Rome, I put out some feelers for other chairs, with discouraging, even humiliating, results. For instance, I still regret having asked His Excellency Professor Nicola Parravano, accademico d'Italia, to communicate our note announcing the discovery of element 43 to the Accademia dei Lincei as a gesture of appeasement. On this occasion, I saw manifest signs of anti-Semitism, and they were not the first. Anti-Semitism had always been endemic in Italy, but it had not prevented talented people from making their way. Now one felt, however, that the disease was getting worse.

My father bought us a brand-new modern apartment on the Piazza Francesco Crispi in Palermo, which had windows overlooking the beautiful Giardino Inglese. It was furnished for us by the Florentine firm of Gori and with some pieces designed by an architect friend of mine, which I had brought from Rome. After fifty years of service, I can still admire their quality in my California house.

We were expecting a child in March, and Rasetti's mother and the Amaldis helped us to find exactly the help we needed: Lella, a woman from Abruzzo, who had never been to school, but had uncommon intelligence and personality, and a sweet nursemaid from Poggio, where the Amaldi family had an estate. Both women excelled in their work, were of sterling honesty, and affectionate; they remained Elfriede's lifelong friends.

On March 2, 1937, Gori came from Florence to assemble our furniture; he wanted to do it personally. At about 3 P.M., when he had just finished his work, Elfriede told me that she thought it might be better to go to the hospital, and about two hours later our son Claudio was born. My colleague the professor of obstetrics at the University of Palermo was in attendance, although once in a while he fell asleep. A few days later Claudio developed a sizeable lump on his neck, much to our horror. The pediatrician, a German doctor chosen by Elfriede, who had formerly been her colleague at the Landschulheim in Florence, made an alarming diagnosis, but suggested we show the child to the university's pediatrics professor. The latter, a very elegant Sicilian gentleman, whose looks reminded me of Freud, briefly examined the infant and then said: "Do not worry. It is nothing serious. His neck has been pulled at birth. All he needs is to sleep for a few days with his head tilted and he will be all right." This turned out to be the case.

With the 1936–37 school year approaching its end, we prepared for our summer vacation. Since Claudio was only a few months old, we could not travel far, and we rented a house at Alba di Canazei in the Dolomites, where we occupied one floor and Amaldi another. We also arranged lodgings in the immediate vicinity for the families of Bakker from Holland and of Bernardini from Florence. Unfortunately, this was to be the last vacation I was able to enjoy in the old-fashioned style familiar to me from my childhood. We collected large amounts of wild raspberries, from which we made jam, and of edible mushrooms (which I learned to identify from a German booklet), thus commencing two lifelong culinary hobbies.

In the middle of the summer, I was called to the colors and had to attend a military training school in the ancient seaport town of Civitavecchia, north of Rome, for several weeks. While there, I received a telegram from the rector of the University of Palermo urgently recalling me, because Il Duce, Mussolini, was about to visit and all the professors had to be present. I took the telegram to the colonel commanding the school and applied for leave. The colonel looked at me intently and asked: "In this season is Palermo very hot?" I understood at once the meaning of the question and answered: "It is terribly sultry." To this the colonel responded: "Answer that you are serving in the army and that leave has been denied." I must add that the colonel gave me leave every weekend to join my family at Alba di Canazei, where the weather was good.

While at Civitavecchia, in the deep of night, I received a telephone call with the news that my father, who was at Tivoli with my mother, had been taken gravely ill. Shortly thereafter Bindo Rimini arrived by car and took me to Tivoli, where I found my mother, Riccardo Rimini, and Marco. My father was in a coma, and according to Riccardo, an excellent doctor whom we all trusted, there was little hope of his surviving. A few hours passed, and the situation was unchanged. Somehow rumors of my father's state spread, and people from the paper mill and city authorities made discreet, concerned inquiries. Somebody even started thinking about funeral arrangements. No signs of improvement appeared.

In the afternoon, the patient, still in a coma, passed a lot of wind, and then loudly and clearly spoke some famous lines from Torquato Tasso's Gerusalemme liberata (my translation):

The raucous sound of the Tartarean bugle
Calls the inhabitants of the eternal shadows.

My mother, who was at her husband's bedside, almost fainted. We all rushed in, and to everybody's amazement, my father regained consciousness. In a few hours he was greatly improved. For about a week he slightly dragged one leg in walking, but soon he totally recovered, without visible trace of what had happened in either body or mind. We had been terribly scared. My father's comment was: "Now I know what there is in the beyond: nothing."

Before the summer vacation, Bohr had invited me to one of his annual conferences in Copenhagen, showing that our work at Palermo had not escaped his attention; I was highly pleased and immediately accepted. On the train to Copenhagen, I met Hans von Euler and several other young physicists proceeding to the same conference, which thus began en route. They explained some of the mysteries of the latest cosmic-ray observations, harbingers of what were later called muons, to me.

At Copenhagen, the meetings were extremely strenuous. In such company, one tried to absorb as much as possible, and thus one had to concentrate without interruption for many hours at a time. I was exhausted by the end of each day.

Bohr's residence and lifestyle impressed me; they were truly princely in the best sense of the word. We also made some of the usual excursions, but continued talking physics all the time. I spoke on the new element 43.

On my way back I stopped briefly in Hamburg. From there, on September 15, 1937, I wrote as follows to Riccardo Rimini:

. . . Yesterday evening the Congress ended, with a humorous, but rather moving, feast. We acted in a sort of variety show summarizing Bohr's recent travels around the world. Through the jokes one could feel the respect and almost veneration that everybody feels for Bohr. I could not approach him very much, but I understood that he is one of the most remarkable personalities produced by mankind, and that he hovers in heights incomparably higher than those reached by common mortals, be they even Fermis. Also morally and from a human point of view he must be superior to others. Immediately after the feast I left with [Werner] Heisenberg [winner of the Nobel Prize in Physics in 1932] and his wife. Heisenberg . . . has been a pupil of Bohr's at Copenhagen for three years, and he has done his best work there. Bohr said a few words of good-bye to him and his wife that well-nigh made the company shiver, and everybody was clearly shaken.

I had a bad train trip, because we were continuously disturbed by customs agents, police, and similar characters. Next morning I arrived here and lodged where you see from the letterhead [the Hotel Continental].

The city of Hamburg and Germany in general after such a long absence have a curious effect on me. Although the exterior aspect has somewhat changed, I could not say that the country looks different, in spite of the abundance of soldiers, each stiff as a ramrod. The shops, with the exception of the booksellers, are the same, and so are the public places, but the whole looks to me like a shell without the animal. For me, who knew Germany as the freest country, as a fountainhead of culture for a physicist, as an unprejudiced country for girls, full of new ideas and with a lively intellectual life, it gives the impression of a total void. Void, void, and nothing else. . . .

In any case the result of this whole trip and of this experience is rather to turn me to the future, and now Bohr and his discourses are more alive, or, better, more important to me than memories of 1933.

As already described, I also stopped on my way home at Freiburg to see the Noddacks.

Shortly after the Copenhagen conference I attended a congress held at Bologna to celebrate the 200th anniversary of Galvani's birth, but all I remember of it are visits to Ravenna, previously unknown to Elfriede and myself, and the general dismay at the announcement during the conference of Rutherford's death.

All told, 1937 had been a good year for us both personally and scientifically, although clouded by Corbino's death. Elfriede and I got along together better and better. She proved to be an excellent wife, ever equal to the often difficult demands placed upon her. She took care of Claudio with good sense, helped measure radioactive phosphorus in the lab, ran the household, acted as a secretary, read on her own account, and grew intellectually; in short, she was an excellent companion in every respect. She had also become attached to my parents, who abundantly reciprocated her feelings.

Our weekend trips had shown us a good part of Sicily. Agrigento and Selinunte (the ancient Selinus) on the southwest coast of the island in particular appealed to my imagination, although when we drove to Selinunte, the local boys scratched the paint of our car and spat on our rucksacks out of pure spite, while alternately begging or vainly trying to sell to us some fake old coins. Hiking in the Bosco della Ficuzza, we saw wild peonies for the first time. I did not know what they were, but guessed, remembering them from Chinese porcelain. At the foot of Monte Pellegrino, we found fourteen different kinds of wild orchids in an area of about five acres. Once in a while, we went to Mondello to buy live lobsters or swim.

In spite of everything, I was worried. I knew that the discovery of element 43 had been a stroke of luck, not likely to be repeated at Palermo, and doubted I could develop a sustained research program without radioactive sources and better instruments than the simple ones I had built. The university had assigned me two hundred thousand lire, a substantial sum, but a good part of it was needed for a machine shop and for other indispensable plant; the future was not all rosy. By nature I was inclined to what I used to call "physics without apparatus," in which new ideas make up for the simplicity of the techniques. This attitude derived both from my indifferent ability as an instrument builder and from my education in Rome, where theory prevailed over technique. However, there were limits to what could be done this way. I tried in vain to obtain some money from the Rockefeller Foundation and from the Italian Consiglio delle ricerche.

To invigorate physics in Palermo, I wanted to establish a chair of theoretical physics. There was no scarcity of young candidates who could brilliantly fill it; first among them Gian Carlo Wick and Giulio Racah. I did not consider Ettore Majorana because by then he had become a recluse and never left home. I could count on a good choice because Fermi's opinion would be decisive.

I discussed the subject with the rector of the University of Palermo, the jurist Professor G. Scaduto. He was most cooperative and promised to help me however he could, but was worried that the new professor might regard Palermo merely as a springboard and might not stay long enough to exert a truly beneficial influence. Scaduto wanted a commitment on this point.

The subsequent competition had a peculiar history. Initially, I had expected that the three winners would be Wick, Racah, and Giovanni Gentile, Jr. I never dreamed Majorana would enter the competition, because he had lived in seclusion for several years. Completely unexpectedly, however, he did. The consequence was clear: the three winners would be Majorana, Wick, and Racah; Gentile would be left out. In a theoretical physics competition, the opinions of Fermi and Enrico Persico would be decisive, and both would honestly recognize merit.

Then something unprecedented happened. The appointment committee (Fermi, Lazzarino, Persico, Polvani, Carrelli) met on October 25, 1937, and put forward a most unusual suggestion. It proposed to appoint Majorana as a professor for "exceptional merit" independently of the Palermo competition, and to suspend further deliberations until the minister had acted on this proposal.

I believe, on good grounds, that in order to avoid a defeat for his son, Gentile's father, a former minister of education and still a power in Italian politics, had conceived this plan and suggested it to the committee. With the competition held in abeyance, Majorana was appointed professor at Naples based on exceptional merit. A law allowed for this procedure in special cases involving illustrious persons, and had been used, for example, in the case of Marconi. After Majorana's appointment, the competition was reinstated, obviously without Majorana's candidacy. The three chosen were Wick, Racah, and Gentile. To my delight, Wick came to Palermo not long thereafter. Needless to say, at the time I was completely in the dark about the maneuvers mentioned above.

This was not, however, the end of the story. After a few months in Naples, where he had started his course in theoretical physics, Majorana wrote a suicide note to his colleague Carrelli and took a boat for Palermo. From there he wired Carrelli that he had changed his mind; he also mailed him a letter on the writing paper of the Hotel Sole at Palermo, dated March 26, 1938, saying:

Dear Carrelli,

I hope my telegram and the letter arrived simultaneously. The sea has rejected me and I shall return to the Hotel Bologna [in Naples] tomorrow, perhaps traveling together with these lines. However, I want to give up teaching. Do not think of me as a girl in an Ibsen play, because the case is different. I am at your disposal for further details.

Affectionately, E. Majorana.

It is easy to imagine Carrelli's alarm and dismay on receiving these communications. As Majorana did not show up in Naples, Carrelli contacted Majorana's family in Rome, as well as Fermi. Ettore's brother, Luciano Majorana, who had also been my schoolmate, rushed to Palermo and came to see me; together we tried to trace Ettore's moves through the police. We found only that he had been at the Hotel Sole, as was clear, anyway, from the writing paper he had used. Fermi immediately alerted the government, and Mussolini personally ordered the chief of police at Palermo to use all his resources to find Majorana. To no avail. He had reembarked from Palermo for Naples, but after boarding the ship, he vanished without a trace. In all probability, he jumped overboard and was lost at sea. His body was never found.[16]

On my return to Palermo in the fall of 1937, Perrier and I renewed our investigation of element 43, but the cream had already been skimmed, and results were harder to get. Nonetheless, we succeeded in finding interesting novelties. I had set my hopes for the future on the package, previously described, sent for irradiation at Berkeley. I also started building a linear amplifier to detect the alpha particles I expected from the transuranic elements I hoped would be present in irradiated uranium.

In the meantime I had been asked to join the Rotary Club in Palermo. Italian Rotary Clubs are very different from their American counterparts. At Palermo, the club's membership was restricted to important local civic leaders. Furthermore, the club was definitely not Fascist. My father urged me to join, and knowing me well, strengthened his arguments by offering to pay the substantial monthly fee.

At the Rotary Club I met several interesting and important persons, both visitors and local residents. I remember especially the inspired face of the composer Don Lorenzo Perosi, which could have served as a model for a sculptor representing "Genius." My election to the club was another sign that Sicilians liked and accepted me. One of the members was the excellent rector of the university, scion of an illustrious family of lawyers. We were friends, but not intimates. One day, however, at the Rotary Club, when I went to greet him with a handshake, he surprised me by embracing me with open arms, whispering in my ear: "Watch out. You have behind you the secretary of the Fascio"—the highest local Fascist authority. Mussolini had just forbidden shaking hands as an un-Fascist gesture.

In 1938 Elfriede returned to Germany for a visit. It was the last time she saw her parents. When she got back to Palermo, I met her ship at the pier with a bunch of roses. They did not suffice, however, to counterbalance a scary piece of political news: Hitler's visit to Mussolini, of which the poet Trilussa (Carlo Alberto Salustri) so appropriately wrote:

Roma di travertino
Rifatta di cartone
Saluta l'imbianchino
Suo prossimo Padrone.

(Rome of marble splendor
Patched with cardboard and plaster
Welcomes the housepainter,
Her next lord and master.)

The allusion is to patch work ordered by Mussolini along the route to be followed by him and his guest.

I decided to spend the summer of 1938 in Berkeley in order to study short-lived isotopes of element 43 that could not survive the time it took to get from California to Palermo.

For these summer forays, I used a scientific strategy I had successfully tested years earlier in Amsterdam at the time of my first visit to Zeeman's lab. I prepared a detailed plan of work, rehearsed the techniques I would use, and knew exactly the instruments I needed. With such preparations, once on the spot, it was easy to obtain good results rapidly. In this specific case, I knew how to isolate element 43 from a molybdenum target, and I knew what to measure in the new isotopes, and how.

At the time Claudio was about one year old, and it was not expedient to bring him to the United States for a few months. We thus decided that he and Elfriede would stay in Italy, first in the Alps to escape the summer heat and then at Tivoli. I would return in October for the beginning of the school year.

In 1938 it was very difficult to get U.S. visas. U.S. consulates would not give one a visa unless one's Italian passport was specifically validated for the United States, and the Italian government would not validate a passport for the United States unless it already contained a visa. In theory, this precluded obtaining even a tourist visa. Immigration visas involved additional quota difficulties, practically excluding Italians and Poles. The last fact was important; Elfriede fell under the Polish quota, although she had never been a Polish citizen. Rasetti had, however, told me that the U.S. immigration law then in force contained a Section 4(d) that permitted entry, irrespective of the quota system, to artists, priests, and professors of a recognized university. At the time this did not concern me, because I only wanted a tourist visa, but it became vital later.

Under these circumstances I went, with my passport, to see an important official of the appropriate department. As a last-minute inspiration, I also stuck Elfriede's passport in my pocket. Our conversation proceeded approximately as follows:

"Commendatore, I am professor of physics at the university and I would like to go, for the summer, to study in California. I have a return ticket and I would like to obtain the validation of my passport."

"You know that I cannot validate it without a previous U.S. visa."

"Yes, I know; however, with this system nobody can move any more."

"Ah! You are the new physics professor?"

"Yes."

"The nasty one! I have a nephew who is very scared by your exam he has to pass in October."

"Commendatore, what is your nephew's name? Tell him not to worry."

The commendatore gave me the name, and I added, "I shall remember it; tell your nephew he has passed the exam."

With this, the commendatore took my passport, stamped, and signed it. I concluded: "Many thanks for your kindness; I sincerely appreciate it and shall not forget it. However, I leave here my wife and a child. One never knows. Couldn't you validate their passport too?" And I pulled out of my pocket the other passport, which was immediately validated. I still regret having been unable to repay the good commendatore's kindness; he may well have saved Elfriede's and Claudio's lives. Unfortunately, however, I obtained a U.S. visa only for myself, and not for Elfriede and Claudio.

Before departing for America, I went to Tivoli to take leave of my parents. It was the last time I saw them. Papà took me aside and said to me: "You are right in going. If I were half a century younger, I would do the same." These are the last words I heard him speak. Elfriede and I stopped in Rome and went to see Ada at the Terme of Caracalla, but we were not in a cheery mood.

I embarked for the United States at Naples on June 25, 1938.

پالرمو، الفریده، فیزیک، رم، پرتوزا، فرمی، ایتالیایی، برکلی

مشخصات

جهت مشاهده منبع اصلی و ادامه این مطلب این مطلب کلیک کنید

یک ذهن همواره در حرکت (۲)

Chapter Four—Scientific Springtime (1928–1936):
Smell of Amsterdam's Canals

Ci lasciaron talune una fragranza
così tenace che per una intera
notre avemmo nel cuor la primavera
e tanto auliva la solinga stanza
che foresta d'april non piú dolce era.

(Some of them left us a fragrance
so lingering that we had spring
in our hearts for a whole night;
and the lonely room was so perfumed
that no forest in April was sweeter.)
Gabriele D'Annunzio, "Le mani," from Poema paradisiaco
(trans. Louise George Clubb)

The laurea that entitled me to call myself Dr. Segrè completed my formal scholastic career, but my study of physics was to be a lifelong occupation. In fact, most of the physics that was to form the subject of my later work did not exist when I was at university; not even in an embryonic state. The neutron and artificial radioactivity were far in the future, not to mention particle physics.

Having finished university, I was thinking of the next step, which I hoped would be an assistantship at Rome. I did not have to worry about earning money, because my father could support me without any sacrifice and would do so gladly, but I wanted a salary as an acknowledgment of my work, although not at the price of taking a job that might endanger my scientific prospects.

For the present, fulfilling my military obligations would give me time for reflection. At the officers' training school in Spoleto to which I was sent, I entered a world utterly new to me. My new comrades came mostly from the Italian bourgeoisie, from every region of Italy; most of them were lawyers, literary men, small businessmen or landowners, with very few engineers or technicians.

Discipline was strict and unreasonable. One of the main occupations was changing one's uniform at high speed many times a day. There was enough food, but it was of poor quality. We were taught mainly by noncommissioned officers, who were happy to display their authority and zeal, using methods reminiscent of the Catholic catechism, occasionally peppered with cruelty. I was assigned to the artillery section, and a major gave us theoretical gunnery courses, whose content went back to about 1890.

One of my comrades whom I vividly remember was a Marquis Lignola, who belonged to an aristocratic Neapolitan family. He considered the Bourbons, ousted from Naples in 1860, to be his legitimate rulers and regarded the House of Savoy as usurpers. Lignola was small and somewhat clumsy. The other students provoked him into expressing his extreme opinions and then scurrilously made fun of him. The victim turned his eyes to heaven and "offered his sufferings to Jesus," showing courage, extreme firmness in his opinions (the pope had erred in dealing with the usurper), and strength of character. Soon his tormentors started to respect him and left him in peace.

The strictly disciplined military life and lack of freedom were boring, but restful, because one did not have to think of anything or make any decisions; the sergeants prescribed all our activities. I had taken with me several books: Courant and Hilbert's Methoden der mathematischen Physik, Oscar Wilde's The Picture of Dorian Gray, and similar esoteric reading. I used to read them during a compulsory siesta period after lunch, lying on my field bed. The books, in foreign languages to boot, allowed me to put on airs with my comrades, but also spiritually transported me far from my military surroundings. A few weeks after the beginning of instruction, we had a free Sunday, and a comrade and I used the short furlough by going to Gubbio and other places near Spoleto. I still remember the exhilarating impression of having regained our freedom, albeit only for a short time. We manifested it by carrying our heavy army swords on our shoulders like hoes. It was a childish gesture, which could have brought unpleasant punishment if detected. A little later I was called to headquarters and given three or four days' furlough for Yom Kippur; I did not know I was entitled to this leave and was pleasantly surprised. Several of my comrades proposed converting to Judaism if that produced leaves of absence. I went to Rome by train, put myself in mufti, rejoicing in contact with the soft flannel of my elegant trousers, and, well groomed, went to court Renata J.

Quite unexpectedly one day, Fermi and his wife Laura showed up in Spoleto in their small yellow Peugeot car. The visit greatly raised my spirits because it gave me an opportunity to resume contact with physics and because it demonstrated that my Physics Institute friends remembered me.

At the officers' training school I had my dose of small adventures, such as falling off my horse right in front of an inspecting general. I immediately got to my feet, unharmed, and grabbed the horse by its bit. The good general kindly commented to me that anybody could be thrown by a horse, and that he had appreciated the way in which I had done the correct thing by preventing the animal from running away! I noted that whenever there was an inspection by some visiting bigwig, I was always called upon to aim the guns. My superiors had soon discovered that I was to be trusted to make the required simple calculations correctly, without sign errors, which occasionally pointed the guns backward.

I graduated from the officers' training school on January II, 1929, and resumed work at the laboratory until the following July 1, when I was commissioned a second lieutenant in the anti-aircraft artillery and stationed at Forte Braschi, very near Rome, as I had requested. On this assignment, I did not have much to do. I slept at home, going to the barracks early in the morning with some book on physics to study. However, in my military service, I learned many other things besides physics. My captain taught me a card game called scopone , which I greatly enjoyed, and also revealed to me novel attitudes to life. I had been brought up with the idea that I should work, that everything had to be taken seriously, and that I was expected to excel, or at least to do well. From my captain I learned that zeal was a grave fault; that many problems took care of themselves provided they were left alone; and that when one received an order, contrary to what we had been repeatedly told, prompt execution was imprudent, and that it was advisable to await its countermanding. Furthermore, contact with the soldiers gave me a chance to get to know contemporaries of very different education and from diverse social and economic conditions. I could also see firsthand the differences between soldiers from the various Italian regions. The unhomogeneousness of Italy's population was such that soldiers often did not have a common language, used as they were to speaking dialect. We had orders, moreover, to see to it that soldiers from the rice-eating north and those from the pasta-eating south did not throw away their rations on alternate days, when the food unusual for them was served.

As a commissioned officer, I bought myself secondhand a gorgeous blue cape, which, although not a very efficient protection against cold, was certainly elegant. When I finished my service I sold it to Edoardo Amaldi, then also an officer.

During my service in Rome, I managed to go once in a while to the laboratory and keep in touch, but I did not have time for experimental work. One day I was urgently called from the barracks at Forte Braschi to the Physics Institute at Via Panisperna. For some reason, all the scientists were away, and the factotum of the institute, who did not know English, was faced with an obviously important Indian visitor with whom he could not communicate. I rushed down and found that the visitor was none less than Sir Chandrasekhara Venkata Raman (1888–1970), who in 1930 received the Nobel Prize in physics for his work on the diffusion of light and the discovery of the Raman effect, on which Roman physicists had done important work. I did the honors as well I could, unexpectedly helped by being in dress uniform, with a blue sash and conspicuous gold epaulettes. Raman believed that I had dressed like this to honor him and thanked me; I did not disillusion him by revealing that the true reason was H.M. the Queen's birthday!

During my military service, I was once unjustly placed under arrest for something I had not done. By chance, I mentioned this to a friend of mine, who without my knowledge spoke about it to his father, a powerful general. With surprising speed, my punishment was commuted to a much lighter penalty, and the colonel who had condemned me without even talking to me must have found himself in serious trouble. I was discharged as a second lieutenant on February 15, 1930, and placed in the reserve.

In 1928 I had published my first physics paper jointly with Edoardo Amaldi, a short note in the Rendiconti of the Accademia dei Lincei, introduced by Corbino, summarizing my doctoral thesis.[1] The following year, Amaldi and I published a second paper, dealing with the Raman effect.[2] I did much early work with Amaldi, but because the rules then prevailing in university competitions penalized collaborative efforts, we often divided the work in a friendly fashion after we had finished it together.

Next I wrote a paper on anomalous dispersion in molecular band spectra. The ensemble of the absorption lines near the head of a band gives a peculiar variation of the refractive index, which I explained with Fermi's help.[3] In about the same period, Amaldi and I produced a couple of papers in the wake of Fermi's study on quantum electrodynamics. They contained results similar to those of a famous and often quoted paper by Eugene Wigner and Victor Weisskopf. Our work was done earlier, although less detailed.[4]

Fermi observed strict rules concerning the publication of his work and that of his students. He did not permit publication of completely insignificant results. Results of little importance appeared only in Italian. He allowed publication in the Zeitschrift für Physik, or as a letter to Nature, only of papers he considered important. This wise policy was motivated by his desire to establish an international reputation for our Rome group. He did not want any foreign reader ever to be disappointed in reading one of our papers; there should always be something interesting in them. He applied this rule strictly, and his judgment on the quality of an investigation rarely erred.

Furthermore, when Fermi developed a theory capable of many applications, such as his quantum theory of radiation, he explained the principles to us, gave some examples, and then left to us the satisfaction of finding further applications. Not a little of the work of this period started out like this.

"You live off Fermi's crumbs," my father, who knew no physics, but was a shrewd observer and knew men, once told me. This was quite true, and I did not forget it. Only later was I able to do something truly my own. My mother, who wanted to know whether my studying physics would lead anywhere, once asked Fermi what he thought of my ability. The ever-truthful Fermi answered, correctly and objectively, that it was too early to pass judgment and make predictions. I was not present at this conversation, but knowing both parties, I am sure that my mother continued worrying about the perfectly honest answer she received.

In the late 1920s and early 1930s, we worked intensely, but in a relaxed way. We used to read the most important journals, such as the Zeitschrift für Physik, Nature, and the Proceedings of the Royal Society, eclectically, hunting for experimental inspiration. My official job—a relic of times past—was that of "Conservator of the Tuning Fork," a sinecure that amounted to an assistantship. When students came looking for research subjects, even in theoretical physics, they were often referred to me, because I usually had a good supply of ideas. I would suggest a problem and explain it to the student in detail. However, when it came to technical details, I often had to send the student to Fermi, who instantly gave the key to the solution. The problems I set were usually in atomic physics or connected with it. I asked Fermi why he did not give out the problems himself; he answered that those he thought of were usually too difficult for students, and that those at their level did not interest him. When Fermi and I co-authored papers, I was often entrusted with the writing. I did not mind writing, and I was proud of the assignment. "It is clear that since you will never get the Nobel Prize for Physics, you are preparing yourself for the Literature Prize," my friends teased.

The study of theoretical physics at Rome progressed under full sail. Fermi was obviously not only a first-class theoretician but a superb teacher; one could not ask for more. He had contacts through conferences and visits with the principal theoreticians of his own age, as well as with Arnold Sommerfeld, Paul Ehrenfest, and some others of the previous generation. Soon postdoctoral fellows from abroad started to come to him, to learn and work under his inspiration. Among the first to arrive were Hans Bethe, Rudolf Peierls, and George Placzek, who acclimatized himself to Rome better than the others, learning Italian and striking up a solid personal friendship with Amaldi and myself. Others who followed included Edward Teller, Fritz London, Felix Bloch, D. R. Inglis, and Eugene Feenberg, who became Majorana's particular friend.

The situation in experimentation was different. One cannot learn the experimental art from books, and we felt the need to go see what happened elsewhere and to learn techniques on the spot where they were practiced. Franco Rasetti was the first to take off, in 1929, going to the California Institute of Technology at Pasadena, then dominated by R. A. Millikan. I do not know what influenced his choice. The Rockefeller Foundation granted him a fellowship.

The Rockefeller Foundation was a great benefactor of physics in that period, helping it through the general economic depression and, later, Hitler's persecutions. A shrewd and farsighted choice of Fellows was at the base of the Foundation's success. Looking today at a roster of Fellows of that period, one wonders at the sagacity of the selection, and the wonder grows when one considers that Fellows were appointed at an early age, often before the work that later distinguished most of them. The selection occurred on the basis of recommendations by two or three established professors whom the Foundation trusted, mostly in the applicant's country of origin. In Italy, it seems that these advisors were Volterra, Levi-Civita, and Corbino, a choice that in itself shows the Foundation's sagacity. All three were honest, experts on their subjects, and well informed about the local situation. They were not in the good graces of the Fascist government, but if this was resented in Italian high places, it did not matter to the Foundation.

Rasetti did very well scientifically and personally at Caltech. He accomplished important work on the Raman effect in gases and fostered the good reputation of the Rome group. He also visited Berkeley, from where he sent me a postcard. At the time he had the impression that Caltech was way ahead of Berkeley.

When he returned home, he spoke only of California's wonders: of Mount Whitney, which he had climbed in winter, of Pasadena's orange groves, of the wealth of American laboratories, of the attractiveness for him of the American way of life. He also proudly showed off a toothbrush he had bought in Hawaii. Needless to say, he would drive only an American car and bought a Ford.

Back in Rome, Rasetti continued to do fruitful work on the Raman effect. I too tried something on the subject without obtaining anything of importance. Amaldi and Placzek studied ammonia with better results. All this work on the Raman effect lasted into 1931.[5]

In November 1930, in the form of a very short letter, I sent Nature the first paper of any importance thought out and executed entirely by myself.[6] Atomic theory gives the laws according to which the electron jumps from one atomic energy level to another, emitting photons. Sometime these rules are violated and there are so-called forbidden transitions. My little discovery concerned certain (S-D) forbidden transitions in the spectra of the alkaline metals, and the paper shows that they are owing to electric quadrupole radiation, neglected in the usual first approximation calculations. The proof is obtained by observing the Zeeman effect of these lines. I examined absorption lines because emission lines are too weak. The experiment was very simple, although at the limit of the resolving power of the instruments available to me in Rome.

The best instrument I could use was a large Hilger prism spectrograph bought by Professor Lo Surdo, and located in his rooms. Lo Surdo very kindly and generously gave me permission to use this instrument. After a few days of work, I succeeded in seeing with my own eyes the potassium absorption lines delineated on a violet continuum produced by a hydrogen discharge. When I energized the magnet in which I had placed my absorption tube, the lines broadened and almost disappeared. With a little more work, I adjusted the instrument to obtain its maximum resolving power. I still remember my great elation in recognizing that the Zeeman pattern I was seeing was the one I expected for quadrupole radiation. This was my first small discovery, and it made a permanent impression on me. If my previous work could be called "Fermi's crumbs," this was my own. Furthermore, it had been obtained rapidly, which enhanced its impact.

My friends at the Physics Institute bestowed upon me the title of "Lord Quadrupole," and, more important, Fermi told me to publish the work in the Zeitschrift für Physik .[7] The self-confidence of young scientists is a delicate plant. Even Fermi, who looked so self-assured in later years, and had performed extraordinary feats when very young, was not sure of himself until he went to Holland at about the age of twenty-one.

What I had seen in my study of the Zeeman effect of the S-D combinations in potassium was conclusive, but did not reveal all the details one would have liked to know. Unfortunately, the instruments at my disposal in Rome could not give more; I had squeezed them to their limit. I was thinking about what to do next when the great Dutch physicist and chemist Peter Debye visited Rome. There was a reception in his honor at Enriques's house and I was invited. Debye inquired in a friendly way about what I was doing, and I told him about my quadrupole work, adding that I was at a dead end for lack of adequate instruments. To my surprise, Debye sternly answered that my complaints were mere excuses; only lazy people were stopped by so-called lack of means. At the time, I was hurt, but the lesson sank in and was highly beneficial then and later. Debye himself suggested that I try going to some foreign laboratory. Four laboratories seemed likely to have a diffraction grating (a device consisting of narrowly spaced slits used for measurement of wavelengths) adequate to my project: E. Back's in Tübingen, H. Cohnen's in Bonn, F. Paschen's in Berlin, and Pieter Zeeman's in Amsterdam. I wrote four letters explaining what I wanted and asking for hospitality. (My father was more than happy to pay my expenses, so I did not need financial help.) Back did not reply; Cohnen said that his grating was at the moment out of commission, because his institute was being rebuilt; Paschen told me that he liked my idea, and that he had just put one of his doctoral candidates to work on it. I was furious at this unexpected answer, but the project must have come to naught, because I never heard any further news of it. Zeeman, a Nobel Prize winner and the discoverer of the celebrated Zeeman effect,[8] told me to catch a train and come to Holland.

I did so without delay, and arrived in Amsterdam at the beginning of the summer of 1931. After finding lodgings at a pension, I introduced myself to Zeeman and told him my precise work plan. Personally, Zeeman was most courteous, benevolent, and affable. He was then sixty-six years old and had ceased active laboratory work. I had the impression that he was not conversant with modern theory, and in particular with quantum mechanics, which was then still a relatively new field. On the other hand, he was a superb experimenter and a master of optics. In any case, talking to him was most instructive. His way of considering an experiment was new and unexpected to me. He had a refreshing diffidence about theory, and while he did not underestimate its power, he knew that nature had more imagination than we did. He thus pushed for thoroughness in experiments, saying that something unexpected was likely to happen. He was right, even in my simple case, when everything seemed predictable.

Zeeman immediately told me that his diffraction grating was the greatest treasure of his laboratory, and that he could not entrust it to me alone, since I did not have any experience in its use. He suggested that I collaborate with Cornelius J. Bakker, a doctoral candidate of his, who was familiar with the grating and with other delicate instruments in the laboratory. I found the proposal reasonable and fair and accepted it at once. Fortunately, it turned out that Bakker was a very nice person and soon we struck up a close friendship that lasted until his untimely death. I still have his portrait in my study.[9]

I immediately started preparing an absorption tube containing potassium. For this purpose, I cut off a piece of potassium and replaced the rest of it in what I believed was the bottle from which it had come. I had overlooked the presence, next to it, of an open bottle of acid. Without looking, I put the residual piece of potassium in the wrong bottle. For about half a minute nothing happened; then a tremendous explosion shook the laboratory. Everybody ran to see what had happened, and I can hardly say how I felt, although I was, fortunately, bodily unhurt. I deeply admired the calm Dutch, who gave no sign of commotion and did not ask me to leave.

The work, which started so dramatically, continued smoothly and successfully. We rapidly obtained all the expected results, as well as several more that rounded off and completed the picture. Zeeman took a liking to me, and one day he asked me about my plans for the near future. I told him that I had applied for a Rockefeller fellowship, but that nothing seemed to be happening. Zeeman remarked to me that he knew somebody in the Paris office of the Foundation, but said no more. By strange coincidence, about a week later I received a letter announcing the grant of the fellowship. Although he never told me so, I suspect that Zeeman may have had a hand in it. When I left Amsterdam to return to Rome, Zeeman told me that whenever I wanted to come back to work in his laboratory, I would be welcome. I subsequently took advantage of this cordial invitation, returning to study different types of forbidden lines, always together with my original co-worker and friend, Bakker. Zeeman also gave me a picture of himself with a warm inscription. He was not far from retirement and possibly thought of me as one of his last disciples.

During my stay in Holland, I became acquainted with its cigars. Zeeman invited me to a couple of very formal and elegant dinners at his home, on the occasion of which he offered his guests exquisite cigars, which I liked. I noted the brand and kept buying it, although I later switched to Otto Stern's favorite brand, which was available in Germany and was equally good.

Many months after publication of our papers on quadrupole radiation, I received Back's response to my application to work in his laboratory; in reply I sent him a reprint of our work.

In the summer vacation of 1931, I went to England for the first time. Between the day Zeeman's lab closed for the summer vacation and a date I had with Amaldi and Rasetti for a hiking tour in Norway, there was time for a short visit to London. I boarded a ship and saw a young man, about my age, with skis. It occurred to me that he was possibly a student who had spent the winter in Germany at some university and was now returning home. Hazarding a wild guess, I asked him whether he had been studying with Sommerfeld. Incredibly, my surmise turned out to be right, and the young man was absolutely flabbergasted. He was very friendly, found me a suitable hotel in Russell Square, and offered to help me to orient myself in London. In exchange, he asked that I join him for my first English breakfast, because he wanted to see my reactions. Undeterred, I ate porridge and haddock and drank tea, all of which I liked, much to my new friend's surprise.

My first impression of England in 1931 was of a great imperial power at sunset. As I wrote home, one saw a thousand signs that the country had passed its zenith. My parents had witnessed the coronation of Edward VII in a very different, splendid period. While in England, I visited Cambridge, where I saw J. J. Thomson but did not talk to him.

Soon thereafter, I met Amaldi and Rasetti in Oslo. We had planned a long hiking trip on Norway's glaciers. We left Oslo by train and alighted at 2 A.M. at Finsoe in daylight. We started walking on the Hardanger Fjell until we reached the sea. Later we explored other fjords by boat and on foot.

On my return to Rome, I kept working on forbidden lines and found other interesting features of their Zeeman effect, revealing their origin, in cases where they could not be the result of quadrupole radiation. Furthermore, theory indicated that there should also be forbidden quadrupole lines in X-ray spectra. I made a systematic search of the literature to see if by chance somebody had observed them without understanding their origin. To my joy, I found that that was indeed the case.[10] All this work was noted, and I had the satisfaction of seeing myself quoted in a new edition of Sommerfeld's famous treatise, Atombau und Spektrallinien .[11] Sommerfeld was always ready to help young scientists and had excellent relations with the Rome group.

In line with our program of learning new experimental techniques abroad, Fermi suggested I spend my Rockefeller fellowship in Hamburg, where I would be able to study vacuum technique (one of our weaknesses) and molecular beams under Otto Stern.[12] He made the necessary arrangements with Stern, and at the end of 1931, I set out.

Fermi and other friends had described Hamburg's wretched climate and dark, wet winters to me, and I found that they had not exaggerated (they did not, however, know what came after—that is, the long, beautiful northern spring, unknown in Italy). I installed myself satisfactorily in a rented room in a private house. The Rockefeller fellowship stipend of $150 per month made me rich and, to satisfy the usual pride of spoiled children (figli di papà ), I did not want any supplement from home. Soon after my arrival at Hamburg, following Fermi's advice, and as an act of courtesy, I visited the Italian consul. This gentleman opened my eyes to the German politics of the time, and even more so to Italian foreign policy, giving me a well-reasoned lecture on anti-Fascism. It seems that among Italian officials there were some who thought independently and had the courage of their own convictions.

Stern was then in the process of making important discoveries and was entirely submerged in his work. He used to arrive at the laboratory every morning at about 10 o'clock; at noon he had lunch with his assistants and guest workers, then returned to the lab, if necessary until late in the evening. The schedule depended considerably on the behavior of the instruments and the vagaries of the vacuum.

Stern suggested that I finish an experiment on the dynamics of space quantization and explained the motivation and theory behind it to me, as well as the details of the existing apparatus. This had been built by my predecessor, the American T. E. Phipps, whose fellowship had expired before he could obtain results. I asked Stern to teach me some physico-chemistry, and in several conversations he gave me interesting illuminations of thermodynamics.

After a while he left me to myself. I tried to learn techniques by watching Stern, as well as younger people such as F. Knauer, Otto Frisch, R. Schnurmann, and B. Josephy. Stern's institute was small in size and in number of scientists, but in spite of this there were not many exchanges between its workers. Schnurmann was the most open, and he introduced me a little to German life. Others had their girlfriends or other concerns, and as soon as the day's work was done, they left on their own private business. Frisch served as Stern's personal assistant at that time and was involved in two major experiments, a demonstration of de Broglie's waves with helium atoms, and the measurement of the magnetic moment of the proton.[13]

Stern taught me a way of experimenting that I had not seen before. He calculated everything possible about his apparatus, such as the shape and intensity of the molecular beams he expected to generate, and did not proceed until preliminary experiments were in complete quantitative agreement with his calculations. This modus operandi slowed down the preliminary work, but it shortened the total time by making it possible to avoid errors and was absolutely necessary for the extremely difficult experiments Stern was conducting. The method allowed him to localize sources of misbehavior in his apparatus and of failures, and to come to a firm decision as to whether there were new and unexpected results, which occurred repeatedly. It was a rigorous and most useful schooling, very different from Zeeman's, but just as valid. I learned much from both, more in the philosophy of experimentation than in technical details. Years later, I saw the totally different, much more pragmatic and empirical, approach taken by Ernest Lawrence. Tutte le strade portano a Roma.

There was also an active theoretical seminar at Hamburg. Pauli had been there until recently; William E. Gordon and later H. D. Jensen followed him. Hermann Minkowski, who later became a noted astronomer, was a lively member of the company. W. Lenz was older, and he seemed to me less interested in current problems.

As to my own work, having thoroughly studied the apparatus I had inherited, I concluded that to make it work, there needed to be a radical change in the method used for producing certain magnetic fields, although I had no idea how to achieve this. I had long admired James Clerk Maxwell's Treatise on Electricity and Magnetism (1873), however, and one day, while looking at an illustration in it of the magnetic field produced by a rectilinear current in a homogeneous magnetic field, I immediately saw the solution to my problem with molecular beams. The theoretical analysis had to be changed, but that seemed to me more feasible than following Stern and Phipps's original experimental plan.

Stern approved my idea as soon as he heard it, got me the few extra parts I needed, and told me to rebuild the apparatus in the way I proposed. As to theory, I knew whom to look to for help. I wrote a letter submitting my problem to Ettore Majorana in Rome, and soon received the answer I needed. By then it was spring, and over the Easter vacation I went to Rome, where I reported all I had seen and discussed at Hamburg. There was enough to keep my theoretical friends busy, and Majorana, Gian Carlo Wick, and Ugo Fano were soon struggling with three different problems strictly connected with the Hamburg experiments.

Europe now seemed to me to be destined for catastrophe. Naturally I did not acquire this foreboding in one day; it grew slowly. Already in 1929, during a trip to Germany with Angelo and Rasetti, I was dismayed by the fanatic enthusiasm with which a group of children on a boat on the Rhine were singing "Deutschland, Deutschland, über Alles." Later events, my life in Hamburg in the last years of the Weimar Republic, and conversations with colleagues convinced me of the deadly seriousness of the Nazi menace; they were a band of fanatics ready for anything. I could not anticipate what "anything" meant, but I included in it a major war—that is, a world war, or at least a European war.

Italy's position seemed to me ambiguous, and I did not know on which side of the fence she would come down. I realized that the Duce's big talk was mostly empty bombast. My profession fostered cosmopolitan attitudes and relations. Both Fermi's and Rasetti's horizons consistently extended beyond Italy, and they often considered emigration. It was fundamental for me that my wife share my mobility, because I might find emigration from Italy desirable or, God forbid, necessary. Any future wife must agree with me on this in advance. I sometimes touched on this issue with my physicist friends, and I spoke freely about it to Riccardo Rimini. At that stage, I was not thinking of the dangers of anti-Semitism, but rather of the situation as a whole.

I did not expect too much from Italian girls. Indeed, perhaps I expected too little of them. My parents on the other hand were eager to see me married to an Italian Jewish girl and suggested I meet some young women who looked suitable to them. One was in Ferrara, where Riccardo was then working in a hospital. On the pretext of visiting him, I met the girl, but I barely remember her. After the war, I learned that she had been murdered by the Nazis.

Later it was the turn of a Neapolitan beauty, who had many advantages. We went for a walk together and I said something like: "Neither of us is a child, and we both know perfectly well why we are on this walk together. I will speak openly; because of my profession and other circumstances, it is possible, or even probable, that I shall end by emigrating. What do you think of it? Could you adapt to life outside of Italy?" The girl was somewhat taken aback and haltingly said that she could not live far from her mother and from Naples. That ended the conversation.

There was another Italian girl, whom I had loved for over ten years, and about whom I had thought seriously many times. The trouble was that I did not succeed in conquering her heart in spite of many efforts and great sufferings on my part, and she married somebody else. I have remained her constant friend.

The first university competition I entered was sponsored by the University of Ferrara and decided on October 31, 1932. There were many competitors older and more ignorant than I. Among my contemporaries, Bruno Rossi already had a reputation for his work on cosmic rays. The judges were Quirino Majorana, Alfredo Pochettino, Carlo Somigliana, Luigi Puccianti, and Fermi, who was the only one who understood contemporary physics. Fermi, preserving the secrecy demanded of the panel, never told me what happened, but I learned about it from other sources. It seems that the majority of the committee said something like: "We have the votes to do whatever we want, no matter what you may say, Professor Fermi. We are, however, considerate, and we shall permit you to choose one candidate. We shall choose the other two." And they selected O. Specchia and C. Valle. Fermi pondered the situation and chose Rossi. I was thus not one of the three winners. Fermi did not know it, but by not selecting me, he had conferred upon me an inestimable benefit. It was a true blessing in disguise, not the last of my life.

This did not prevent me from sulking for a while. Rossi and I were virtually the same age, and our papers, although in very different fields, might have been seen as of comparable quality. It was noted that Fermi had preferred a Florentine to a Roman, and to his pupil. I am sure that Fermi's vote reflected his deeply considered evaluation of merit, and today, so many years later, I think he was probably right. At the time, however, Fermi saw that I was angry and unhappy. With a rare show of solicitude and affection, he told me that I should not be angry, that there would be other competitions, that I was young, and that what counted above all was to do good physics.

He proposed that we do some research together, which quickly cured my sullenness. We investigated hyperfine atomic structures with a view to showing that they could be completely explained by the nuclear magnetic moment, and that there were no other nuclear forces at play. The paper we subsequently co-authored contains the standard Fermi-Segrè formula.[16] During this work we labored together for hours on end, and on a couple of occasions I fell asleep out of exhaustion while Fermi was talking to me.

In the summer of 1933 I visited America for the first time. After his 1929 experiences, Rasetti had stuffed our heads with fabulous descriptions of the United States—the promised land, according to him. He declared he could not drive Italian cars anymore and imported a Ford Model A, in which we traveled extensively. Rasetti's tales persuaded Fermi to go and see for himself, taking advantage of an invitation in 1930 from the University of Michigan at Ann Arbor, which held famous summer schools on theoretical physics. Invitations were extended to young European luminaries, as well as to about thirty American students and postdoctoral fellows, and Fermi's old friend G. E. Uhlenbeck, who was on the Michigan faculty, always attended. In Rome, Fermi had reformulated P. A.M. Dirac's quantum theory of radiation in a form much easier to understand than the original papers and had made many illuminating applications of the theory. In his course at Ann Arbor, he reported on this investigation with extraordinary success. He was reinvited many times later, and whenever he could, he accepted. Fermi loved the American atmosphere, and in particular Ann Arbor and its stimulating school. In fact, he became one of its mainstays.

In 1933, Fermi suggested that I accompany him, and I gladly accepted. I first stopped at the Long Island home of G. M. Giannini, a contemporary of mine who had also studied physics in Rome. Then I moved to Ann Arbor, where I shared a room in a filthy fraternity building that had been vacated for the summer.

Both Fermi and I were eager to improve our English pronunciation, and we asked some of the students to point out where we were weakest. It seems that our pronunciation of the letter r was particularly bad. I accordingly invented the exercise "Rear Admiral Byrd wrote a report concerning his travels in the southern part of the Earth," which we declaimed at least twelve times a day, if possible in the presence of somebody who could correct us. Fermi and I bought a secondhand car from D. R. Inglis, which we named "The Flying Turtle" because of its performance, and toured the state of Michigan in it, eating very well as the paying guests of local farmers. We thus discovered delicious rural American dishes, which are difficult to obtain in the cities because they require very fresh vegetables.

To justify my presence at Ann Arbor, I tried doing some experimental work, but the humid heat of the place prevented me from working efficiently and I did not get anywhere. In trying to fit a rubber tube onto a glass tube, I badly cut my left middle finger. I went to the hospital, and as soon as he saw the wound, before I could open my mouth, the doctor said "You have been trying to fit a rubber tube to a glass one." Later I saw other victims of the same accident.

On my return to Italy, I felt that although I had spent a year learning about molecular beams, and had even performed a creditable experiment with them, I was more interested in forbidden lines, which had a special attraction for me. After the study of quadrupole radiation, it was clear to me that there were also other mechanisms producing forbidden transitions, among them the presence in a discharge of ions that created random electric fields. I devised a simple theory to explain this effect and verified it with Bakker's help by studying the Zeeman effect in a suitable case.[17]

Besides using the field produced by ions in the discharge, one could think of using an external electric field, under more controllable conditions. Bakker and a colleague named Kuhn performed this experiment, while G. C. Wick and I developed the theory. There were some reasons for thinking that the behavior of potassium and sodium would be different. Bakker had studied potassium. Amaldi and I experimented on sodium. During these experiments we observed high quantum states, corresponding to enormous orbits. I called them "swollen atoms"; today more scientifically, but less pictorially, they are called "Rydberg states."

We noted then that the foreign gases we had introduced into our absorption tubes to prevent distillation did not broaden the lines as much as we had feared, but rather, to our surprise, shifted them. We mentioned this unexpected phenomenon to Fermi, who thought about it a little and then said that it was probably because of the dielectric constant of the gas we had added to the alkali vapor. This effect had to be reckoned with, and he calculated it at once. However, for some gases the observed effect had the sign opposite to that expected. Surprised, we went back to Fermi with the puzzle. This time it took Fermi several days to come up with an additional cause of level shifts, and he wrote an important paper on the subject, which for the first time introduced the idea of what is now called a "pseudopotential." Subsequently I noted that swollen atoms should show a term in their Zeeman effect, quadratic in the applied field. In the usual theory, this term is justifiably neglected, but I experimentally showed its importance in suitable cases.[18]

The quadratic Zeeman effect, the shift of the lines, and the effect of the electric field on lines near the series limit have been extensively investigated and now form a subdivision of spectroscopy. Amaldi and I summarized our investigations in a review article that appeared in a festschrift for Zeeman's retirement.[19]

At about this time my father made an important decision that was to affect the future of everyone in our family. He was over seventy years old and was increasingly inclined to leave the management of the paper mill to Marco, by now his undisputed successor, because Angelo was busy with completely different matters and I was committed to physics. In his business, my father carefully observed developments, gave general directions, and as the sole stockholder had the final say on everything, but he left the day-to-day management to Marco, whom he tried to groom as his successor.

The paper mill had prospered substantially, but especially in later years, Father had chosen to invest profits in real estate rather than in enlarging and modernizing the mill. I do not know why; possibly there was a certain amount of tacit mistrust of Fascism and its economic policies. He also planned the disposition of his estate, which he wanted to divide into three parts of equal monetary value. He thought the mill should go to Marco, who worked there, and that Angelo and I should receive assets we could easily administer independently of Marco. In recent years I had been abroad for extended periods and had often hinted that I might emigrate. Furthermore, I had seen Nazism with my own eyes and had no illusions on the subject.

Up to 1933 I had not paid any attention to financial problems. Papà handled them with much greater ability than I could hope to muster, and I had no money of my own. I had occasionally intervened in personnel questions at the paper mill, in particular defending Bindo Rimini, who had been attacked by Marco. In this connection I once made a trip to Florence to investigate certain paper sales, and proved that Marco had blamed Bindo unjustly. Bindo remained deeply grateful to me for my help. I also introduced my friend Giovanni Ferro-Luzzi at the paper mill, hoping he might keep an eye on what was going on.

In years past, his foreign business had produced some assets outside of Italy, and my father had left them there, as was legally permitted at the time. About 1933, however, the Fascist government promulgated new laws demanding the repatriation of foreign money, with severe penalties for transgressors. These laws worried my father, and one day in the fall of that year he invited a prominent banker who was his friend and advisor to his office, along with Marco and myself, and asked for our opinions on the subject. The banker at once said something along the lines of: "You did not leave this nest egg overseas for times in which the export of assets was permitted. You left it there for times like the present. The new laws are the best proof of the importance and prudence of keeping such a reserve." He also pointed out that there was currently a flurry of capital exports on the part of industrialists, professionals, and people of means. Why should my father give up his own safety net? The argument convinced me at once. Our friend had hit the nail on the head.

Father said that at his age he wanted a quiet life. Marco signaled his own importance, saying what I expected of him: he was in the limelight and could easily be subjected to an investigation; he had a family to protect, and being such a prominent industrialist, he had to be prudent.

It was my turn to speak, and I said something like: "I am a physicist who often works abroad, and I might emigrate. I am not a person in the public eye. You may transfer the funds to my name, and I shall keep the money for the benefit of the whole family. I insist however in being the only one with access to the account." Papà agreed on the spot and told me to make the necessary provisions for disposal of the money in the event of my death. Angelo was not consulted; my mother was not present, but I am sure that my father had informed her.

To make the necessary arrangements, I needed to go to Switzerland without attracting attention, so over the Christmas vacation I went skiing near the Italian border with some friends, including the physicist Giulio Racah. We encountered foul weather, and, what with storms and avalanches, I had several close shaves. Escaping with nothing worse than a broken ski, however, I was able to enter Switzerland without seeing any police or custom official. There I transferred the money to my name and deposited with a notary a letter, to be delivered only upon presentation of my death certificate, giving access to my account. In this way we created a secret fund that was to be providential five years later when Italy started its racial persecutions.

From Switzerland I returned to Italy by train and then went to the Val Gardena to join some physicist friends who were there for a Christmas skiing vacation. Several days had passed since my adventurous crossing of the Alps, and as a result of my falls on the frozen snow, my buttocks had acquired impressive green and black spots, of hues rarely seen. I could not deprive my friends of the fun of such a sight. Later, Fermi, sitting on a bed in the small hotel room, explained to us his new theory of beta decay, as yet unpublished.

Physics in the meantime was taking an important new turn for us. For some time Fermi, and we as a consequence, had been making longrange scientific plans. Fermi felt that the golden age of atomic physics was coming to an end, and that the future lay with nuclear physics. In a letter dated September 9, 1932, he wrote to me: "I have no program for next year's work: I do not even know whether I shall start fooling around with the Wilson Cloud Chamber again, or if I shall again become a theoretician. . . . The problem of equipping the Institute for nuclear work is certainly becoming ever more urgent if we do not want to fall into a state of intellectual slumber."

My personal reaction was that we had just learned spectroscopic techniques, with which we were reaping good results, and that we might persist in that field a little longer. I was, however, open to Fermi's arguments. Amaldi and Rasetti also had their points of view, and we had long, lively discussions on the subject. As was to be expected, Fermi's ideas prevailed, although everybody was left free to do what he liked best. Thus I continued to work experimentally on spectroscopy until we started our neutron work. However, we all increased our reading on nuclear subjects. As a bridge between spectroscopy and nuclear physics, Fermi and I actively investigated hyperfine structure, as already mentioned.

Even my work in Hamburg on the dynamics of space quantization had an unexpected nuclear ramification. In the last weeks of my experiments, Otto Frisch had helped me, and Stern suggested that he sign the paper with me, to which I consented. In spite of all our efforts, we found that the experimental results did not agree with the theoretical expectation, but the experiment had been difficult, for its time, and we were able to find experimental excuses for the discrepancy. A few months later, however, we received a letter from I. I. Rabi inquiring about some experimental details we had not published. I sent them to Rabi, and he answered that the reason for the apparent disagreement between the theory and our results was that in the theoretical calculation, we had neglected the effect of nuclear spin! Had we included it, attributing to potassium a spin of 3/2, theory and experiment would have agreed. In other words, we had without knowing it measured the nuclear spin of potassium. Rabi most generously published all this in the Physical Review .[20]

By 1933 Fermi had started an intensive investigation of nuclear subjects. Amaldi organized a seminar to study Ernest Rutherford, James Chadwick, and C. D. Ellis's recent book Radiations from Radioactive Substances.[21] Soon Rasetti and Fermi started learning experimental nuclear techniques. Together they built a gamma-ray spectrograph using a bismuth crystal; then, following a model used by Lise Meitner, they designed a cloud chamber, which was built in a machine shop in Rome. All of us together built some Geiger-Müller counters that more or less functioned. Rasetti was the moving spirit in this preparatory work; he had also been working in Meitner's laboratory to learn some radiochemistry. In particular, he had learned how to prepare Po + Be neutron sources and had taught me that art. Fortunately, G. C. Trabacchi, director of the Istituto fisico della sanità pubblica, which was located in the same building as the Physics Institute, had a gram of radium for medical purposes and benevolently lent us a fraction of it, making our neutron work possible. We thus laid a respectable experimental foundation for nuclear studies.

To further enhance our readiness, Fermi used his clout as a member of the Accademia d'Italia to promote a small international nuclear physics conference, which was held in Rome in October 1931 and attended by about thirty well-chosen physicists. At the conference I had the privilege of cleaning the blackboard for Marie Curie. Regrettably, I did not do it to her satisfaction, and she told me so in no uncertain terms. The timing of the conference was unfortunate, because it was a few months before the discovery of the neutron, which opened a new era in nuclear physics.

By 1932 Fermi had already accepted an invitation to report on nuclear physics to a large international conference in Paris, and he also participated in the famous 1933 Solvay conference devoted to nuclear physics. Shortly thereafter, on his return at Rome, he invented the beta-ray theory—in his own opinion, his theoretical masterpiece. In it, developing Pauli's neutrino hypothesis, he formulated a quantitative theory of beta decay. This theory introduced the so-called weak interaction, which turned out to be a new "force of Nature," as Faraday would have said. After Fermi's death, the weak interaction revealed startling properties, such as the nonconservation of parity and, ultimately, deep relationships with electromagnetism.

Great events, however, were incubating in a different field. In February of 1934 we were stunned by the announcement of Irène and Frédéric Joliot-Curie's discovery of artificial radioactivity. By bombarding light elements with alpha particles, they had obtained new radioactive isotopes of common elements that decayed by positron emission. Fermi thought at once of the advantage of using neutrons as projectiles. Although the available neutron sources emitted many fewer neutrons than the alpha particle sources emitted alphas, the much superior efficiency of neutrons overcompensates this handicap. This is because the alphas are repelled by the nuclear charge and do not penetrate the nucleus. The neutrons on the other hand always end by penetrating a nucleus.

Thanks to the previous year's work, we had all the tools ready for testing these ideas. Rasetti, who had contributed so much to it, was in Morocco, where the king was decorating him with some order. Fermi recalled him by telegram, but he answered that he did not want to be disturbed. Fermi proceeded alone and, using a Rn + Be source, tried to form new radioactive isotopes in all elements, in order of increasing atomic number. He first succeeded with fluorine (Z = 9).

The next step was to try to activate all the elements, and to study all the radioactive isotopes formed. This formidable task was beyond the capabilities of a single person, even of a Fermi. Having struck scientific gold, he most generously invited Rasetti, Amaldi, and me to take part in its exploitation.

We were talking about the need for professional chemical help when Oscar D'Agostino showed up at the Physics Institute. He was a graduate of the department of chemistry at the University of Rome and was spending a postdoctoral fellowship in Marie Curie's laboratory in Paris learning radiochemistry. He had returned to Rome for the Easter vacation. We told him our problems, and Fermi invited him to help us. He postponed his return to Paris, and the delay extended indefinitely.

In the neutron work, each of us assumed special duties, although we collaborated on all the phases of the investigation. Fermi was the natural chief, not in the sense that he told us what to do on a detailed basis, but rather in that he set the general guidelines. If there was any problem, we talked it over together, and it is not difficult to guess whose words carried most weight. Once the program was established, each of us took responsibility for some part of it.

From the very beginning of the experiments, we saw that we needed a minimum amount of money beyond the Physics Institute's regular endowment. Fermi had good relations with the Consiglio nazionale delle ricerche. He had been its secretary for physics, and I his assistant secretary. At the present juncture, Fermi asked for help from the CNR and immediately obtained 20,000 lire (then about U.S. $1,000). I doubt whether any scientific grant has ever been more fruitful.

I was charged with procuring what we needed for our work. Luckily, there was no bureaucracy. I could carry our money in my pocket; it was not much, but I could pay cash on the barrel. With this freedom, money multiplied its purchasing power in an astounding way. For chemicals, I turned to a Signor Troccoli, an old and experienced merchant who took pride in stocking a most extensive supply of chemicals. In his youth he had studied in a seminary, and he liked to speak Latin, once in a while offering me some chemical that had been on his shelves for years "gratis et amore Dei." After I explained to him what we were doing, the worthy gentleman helped me in any way he could. However, when, in my ignorance, I asked him for a sample of masurium, he answered, "Nunquam vidi" (I have never seen it). A few years later I realized why. Masurium did not exist.

For some absorption measurements, we needed a gold ingot. I went to the firm of Staccioli, who were dealers in precious metals, and without any difficulty, on the basis of a simple receipt, they loaned me the ingot; I returned to the institute loaded with gold. I purchased necessities that could not be found at Rome through my friend Bakker in Holland.

Work proceeded rapidly. Our group reminded me of a wellrehearsed orchestra, and its conductor, Fermi, got superb music from it. We all outdid ourselves, each achieving more than any of us could have done on his own. The whole was definitely greater than the sum of its parts, Fermi included.

Our communications were published in La ricerca scientifica, the bulletin of the CNR, where Amaldi's wife worked, and it is easy to follow the daily progress of our work in it.[22] We sent reprints to wellchosen, strategically located correspondents who could read Italian, and our reports soon attracted the universal attention of nuclear physicists. Corbino kept in close touch with us through frequent visits to our laboratory.

We systematically proceeded to irradiate all the elements we could find, trying to use our sources as efficiently as possible. We prepared them once a week, because the radon they contained had a half-life of 3.82 days. The operation was delicate, but we proceeded cautiously, and nobody got hurt.

Soon we identified the two reactions, neutron capture followed by proton or alpha-particle emission, or, in the usual notation, (n,p) and (n,a ). We also found that frequently neutron bombardment produced a radioactive isotope of the target, but we did not know whether this was owing to neutron capture followed by gamma-ray emission or by emission of two neutrons: (n,g) or (n,2n). At the time we believed that the more energetic the bombarding neutron, the more efficient it would be in producing nuclear reactions. Only months later did we find out how erroneous this assumption was.

Continuing our bombardments by increasing the atomic number of the targets, we arrived at thorium and uranium.[23] The activities we could produce were weak compared with the natural activity of the targets; hence it was necessary before bombardment to remove from them the different radioactive substances they contained in radioactive equilibrium with the primary substance. This was a long and delicate operation, and the substances removed grew again after some time. We thought that in capturing a neutron, uranium and thorium would form a beta emitter that decayed into transuranic elements, for which we anticipated chemical properties similar to those of rhenium, osmium, and iridium. The nuclear processes occur, but the supposed chemical resemblance is false. We erred in the way we extrapolated the periodic system of the elements. Hahn and Meitner fell into the same trap, as did the Joliot-Curies. Only after several years was it realized that transuranic elements form a family similar to the rare earths.[24]

In 1934, at Rome, we proved that some of the activities formed in uranium bombardment were not isotopic with elements between lead and uranium, but we drew the wrong conclusion that they were transuranic. Like other investigators of this period, we noticed that the total activity produced was much larger than that of the products we were isolating, and we should have further investigated its nature. We did not seriously entertain the possibility of nuclear fission, although it had been mentioned by Ida Noddack, who sent us a reprint of her work.[25] The reason for our blindness, shared by Hahn and Meitner, the Joliot-Curies, and everybody else working on the subject, is not clear to me even today.

Transuranic elements presented a difficult experimental problem, full of pitfalls unless one had the right ideas or impeccable techniques. In fact, in December 1938, Otto Hahn and Fritz Strassmann found the solution to the puzzle through an ironclad experiment proving the formation of radioactive barium in neutron bombardment of uranium.[26]

The outpouring of work mentioned above occupied the spring of 1934. During the summer, the Physics Institute was closed, and Fermi went to South America on a lecture tour. Amaldi, his wife, and I went to the Cavendish Laboratory in Cambridge. On the way, we stopped in London to meet Fritz Paneth, from whom I wanted to learn some chemical techniques, as well as Leo Szilard, with whom we had had some correspondence and who seemed to be, in more than one way, an interesting fellow. We made an appointment for a certain time in the afternoon, but nobody showed up. Around 10 P.M. , we found Paneth with tears in his eyes and Szilard obviously shaken. We did not talk science. Hitler had attempted a coup in Austria; Chancellor Engelbert Dollfuss had been murdered, and no one knew what would happen next. Paneth was Austrian and Szilard Hungarian; the blow struck close to home. Italian mobilization, ordered by Mussolini, foiled Hitler's plan. The attempted putsch should have forced French, British, and other European politicians to open their eyes. Perhaps what they did not want to see was too ugly to contemplate. They hesitated and missed another opportunity of putting an end to Hitler.

Amaldi and I brought with us the manuscript of a paper summarizing the neutron work done in Rome, which we delivered to Lord Rutherford at the Cavendish Laboratory, begging him to communicate it to the Royal Society. He showed keen interest in our paper, took it home, and returned it the next day with some corrections to the English, saying that he was fo

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Acknowledgments

When Emilio, who instructed me on so many things, said that he would leave the publication of his autobiography to me as a "consolazione," his advice was: "Just deliver the latest set of diskettes to the publishers, and they will do the rest."

Well, it wasn't that easy, especially for a perfectionist like me, but I must say that the staff I worked with at the University of California Press were much more than just efficient and friendly. None of them had known Emilio personally, and they only got acquainted with him through his manuscript. When, one after another, the editors told me, "Once I started reading, I couldn't put it down," I knew the book was in good hands.

Thus, to UC Press Director Jim Clark, to editors Eileen McWilliam, Erika Büky, and Peter Dreyer, and to designer Barbara Jellow, I convey my most heartfelt thanks for their interest and dedication in making Emilio's last book what it is now.

To Professor Robert W. Seidel for his conscientious doublechecking of the physics, my most profound gratitude. Last but not least, my deepest thanks to Professor Eugene Commins and his wife Ulla for their help and friendship (the saying "A friend in need is a friend indeed" comes to mind whenever I think of them), and to Professor Owen Chamberlain, whose spontaneous reply to my question, "How would you describe Emilio?" became the title of this book.

ROSA M. SEGRÈ
SUMMER 1992

Preface

I have written this autobiography because I thought it might interest a public curious about the science-dominated period in which I lived. Many other physicists, my contemporaries, have done the same, among them Luis Alvarez, Freeman Dyson, Walter Elsasser, Richard Feynman, Otto Frisch, Werner Heisenberg, Sir Rudolf Peierls, and Bruno Rossi.

Each of them writes from his own point of view and according to his personality. This emerges clearly, for instance, in descriptions of the Los Alamos period; in comparing them, one recognizes the main facts, but the differences of interpretation and the importance assigned to those facts by the authors stand out starkly, as do judgments on persons and events. These differences are interesting and should not be suppressed.

Thus, for example, in reading Peierls's autobiography,[1] which occasionally refers to persons and circumstances I also discuss in this book, I found him to be a much more likeable and gentle person than I am. I am reminded of a remark made to me in the 1960s by the then governor of California, Edmund Gerald "Pat" Brown. He had invited me to a small intimate dinner at his official residence, and during our conversation he questioned me on some points pertaining to the University of California, of which he was an ex officio Regent. I answered as well as I could; he listened, thanked me, and then, laughing, added: "When you speak to a politician you should say those things like this"—and he repeated what I had said in the diplomatic form I should have used. The episode stuck in my mind, but I do not think I have profited from it.

Because the growth of science in this century is such an imposing phenomenon, I believe there is justification for this modest work. It is not just a manifestation of vanity, of gratitude to some, of disaffection with others, or a way of venting my spleen, as one might uncharitably surmise. It is rather a narrative of the life of one of the many scientists who have contributed to the phenomenon. Its appeal may be similar to that offered, in a different context, by the memoirs of one of Napoleon's generals or one of Lincoln's ambassadors.

I have tried to tell the unvarnished truth (as I see it) and to report events the way I believe they occurred, as well as what I felt and thought at the time. I do not like to speak ill of others, and even less of myself, but I have not sought to display manners and tact I never had, and I have tried to treat myself no better than anyone else. I believe it will be clear by the end of the book that scientists are only human.

I thank my friends Renzo de Felice, J. L. Heilbron, Anthony Walsby, Dr. Edgardo Macorini, and the late Avv. Goffredo Roccas, who helped me greatly in various ways. My wife Rosa Mines Segrè has valiantly and patiently helped me in writing this book, through her interest in it, her encouragement, and her criticism. Above all, she kept the old curmudgeon alive.

Chapter One—Chromosomes: Family and Childhood (1905–1917):
Smell of Skunk

. . . mi dimandò: "Chi fur li maggior tui?"

(. . . he asked me: "Who were your forebears?")
Dante, Inferno 10.42 (trans. Laurence Binyon)

A visitor to the Villa d'Este at Tivoli, near Rome, in May 1914 would have been able to see only its gardens and the reception halls on the first floor of the main building. The rest of the palace was closed to the public. Although it was worth seeing, the owner wanted to save on maintenance and did not want to spend money on custodians for these rooms. They contained frescoes by Taddeo and Federico Zuccari, of the same kind as those in the halls on the first floor. Although not masterpieces, these paintings were valuable. Thus the second floor could be used only by someone who, for some special reason, had privileged access to it.[1]

The visitor might one morning have found there a boy of about nine, wearing shorts. He liked reading; in particular he loved La scienza per tutti (Science for everybody), a popular magazine published by Sonzogno in Milan. Its illustrations in color and the many diagrams of machines and apparatus had a special fascination for the boy, whom the visitor might have found intent on reading an account of the working of the automobile engine, with its four phases. The subject was not easy, but in about an hour of concentrated attention he had succeeded in mastering it and, happy to have done so, inscribed it in his memory for life. He then passed on to another article in the magazine, which described the liquefaction of helium by the Dutch physicist Heike Kamerlingh Onnes, who had recently received the Nobel Prize and later discovered superconductivity.[2]

After a while, tired of reading, the boy descended to the garden to play with the gardener's son, his great pal, with whom he had secretly established a small vegetable garden and a tree house hidden by the box hedges that separated the garden paths descending along the slope of the hill. Many fountains and waterworks, as well as peculiar pieces of architecture, embellished the centuries-old park, and the boys had explored every corner of it.

In this peaceful atmosphere, nobody knew that we were on the brink of the first world war—perhaps least of all the owner of the Villa d'Este, Archduke Francis Ferdinand of Austria and Este, whose days were numbered and whose assassination at Sarajevo on June 28, 1914, was to launch the great tragedy that engulfed the world.

In the peace of that morning, Mother called aloud to the little boy from a terrace in the center of the palace, which faced the garden: "Pippi! It is time to go home for lunch." And Pippi, feeling hungry, joined her promptly.

I, Pippi, was born in Tivoli, on January 30, 1905. My father reported my arrival to the civil authorities later than prescribed by law, and to avoid complications, I was registered as having been born on February 1, which became my official birthday. I was called Emilio Gino; according to my mother, the first name reminded her of her great friends Emilia Treves and Erailia Pusterla, about whom more later. The second name honored my uncle Gino, my father's younger brother. However, as a child everybody called me Pippi, a nickname I coined as soon as I started speaking.

My birthplace was a house in a quarter then called Villini Arnaldi. My father, Giuseppe Abramo Segrè, was born in Bozzolo, near Mantua, in northern Italy, on February 2, 1859; my mother Amelia Susanna Treves was born in Florence on July 27, 1867. I was the youngest of three brothers. The eldest, Angelo Marco, was born in 1891 (died in 1969), and the second, Marco Claudio, was born in 1893 (died in 1983); thus my brothers were fourteen and twelve years older than I.

The Segrè Family had lived in Bozzolo for centuries. I believe they originally came from Spain, possibly at the time of the expulsion of the Jews in 1492. All my grandparents died old, but before my birth. The information I have about them comes from what I heard at home or found in documents. My paternal grandfather, Angelo Miracolo, was named Miracolo because his mother was fifty-four at the time of his birth. He was, I believe, a shopkeeper in Bozzolo. I have heard only of his physical strength, health, and gymnastic prowess. When he was about eighty, he retired with his wife to the city of Ancona, where one of his children, Claudio, worked. My grandfather Angelo seems to have liked to scare his family by showing off his acrobatics on the roofs of neighboring houses. He also commented to his children, all very successful in life: "If it were not for the worries you give me, I would live forever." He, his wife, and their son Claudio are all buried in Ancona.

His wife, Egle Cases, was an outstanding woman, both for her brains and for her character. Her children, daughters-in-law, and grandchildren always spoke of her to me with deep affection and high respect. My mother told me repeatedly how much she enjoyed having her mother-in-law in her home at Tivoli, and how she felt closer to her than to her own mother. I have found a subtle echo of this in letters written by my grandmother Egle to her future daughter-in-law, then engaged to my father. The letters, although short, show uncommon understanding and warmth. Egle had received an education well above what was customary for girls of her time. Her home was a center of attraction for the intellectual life, provincial, but not negligible, offered then by a small Italian town.

Angelo and Egle Segrè had four children. The oldest, and the only girl, by name Bice, married a Riccardo Rimini and had four sons. One of them, Enrico, became a professor of organic chemistry at the University of Pavia and is remembered for the Angeli-Rimini reaction of aldehydes. He was the father of Riccardo and Bindo Rimini, my contemporaries and close friends, who will often appear in this story.

The three sons of Angelo and Egle were Claudio (1853–1927), my father Giuseppe (1859–1944), and Gino (1864–1942). They were very close to each other, but not to their sister Bice. Possibly she was a difficult person, as is suggested by the many stories I heard about her. I had only a slight acquaintance with her.

My uncles Claudio and Gino attended the University of Pavia thanks to Collegio Ghislieri fellowships.[3] This college had been created by Pope Pius V at the time of the Counter-Reformation to help talented young men who could not afford an education. With the unification of Italy in the nineteenth century, the laws of earlier times discriminating on grounds of religion had been voided, and Uncle Claudio may have been the first Jew to be admitted to the college.

Claudio obtained his highest degree as an engineer from the University of Turin in 1876; subsequently he went to the Ecole des mines in Paris, where he studied geology. He remained fond of France for the rest of his life, but occasionally (and very loudly) criticized French chauvinism. He still resented unfriendly treatment he had received in the Mont d'Or region during geological field trips. On his return to Italy, in 1881, he went to work for the Ferrovie meridionali, a railroad company, and devoted himself to the application of geology to railroad construction. His personal experience led him to introduce more scientific procedures in the railroad industry, and in 1905 he succeeded in establishing an "experimental institute for the Ferrovie meridionali" in Ancona, which passed to the Italian government on the subsequent nationalization of the railroads. The institute's purpose was to help the railroads by putting the operations of planning, purchasing, building, and testing on a sound technical basis. This simple idea is now commonplace, but in my uncle's time it was new and unusual. Only his enthusiasm and persistence succeeded in carrying it through and in developing an excellent technological laboratory for its implementation.

Uncle Claudio was of short stature and in his later years somewhat deaf. He spoke very loudly and, when angry, tended to use profane language, not permitted at the time in polite company. In 1905 he moved, with his institute, from Ancona to Rome. He settled in a rented apartment in a then-modern building on the corner between Piazza della Chiesa nuova and Corso Vittorio. Uncle Claudio, for his times, was widely traveled, often representing the Italian railroads at international conferences. He told me that at one of these he had met Jules-Henri Poincaré, who, confusing him with the mathematician Corrado Segre (no accent and no relation), was most cordial, changing, however, almost to rudeness when he became aware of his mistake.[4] Claudio had visited all of Europe and Egypt. He never went to America. He used to tell me stories about the czarist Russia of 1908 reminiscent of what I experienced in the Soviet Union in 1956. For instance, he visited the Kremlin and the guide, in return for a suitable tip, allowed him to sit on the throne of the czar, but no tip would buy him an opportunity to take a photo. My uncle also noted that Russia was then, as subsequently, the only country requiring an internal passport.

Since Claudio never married, his nephews—that is, I and my brothers—were the beneficiaries of his paternal instincts. He was a sort of second father to us, someone with whom one could speak about anything, who told us his ideas and was always ready to help us. My brother Angelo often made trouble with some untoward deed, a poorly planned trip, an illness in some strange place, and Uncle Claudio always went to his rescue. It is not by chance that three of his grandnephews bear his name.

When we moved to Rome in 1917, we rented an apartment in the same building as Uncle Claudio, one floor below him, and I was sent to sleep in his apartment. My bedroom's temperature, in winter, was 52 F, but with a good eiderdown it was quite comfortable. In the morning I often had interesting talks with my uncle while showering; furthermore his library, from the Larousse encyclopedia down, nourished my curiosity.

A comical, long-remembered incident occurred around that time. Uncle Claudio's cat, which had disappeared for a few days, possibly wandering the neighboring roofs, reappeared one night in a sorry state, mewing desperately. My uncle let him in and, seeing the condition he was in, said loudly: "Dummy, why do you go looking for adventures? Don't you know that you've been gelded?" Next day a neighbor, highly embarrassed, approached my uncle and said: "Commendatore, you will excuse me, and you can count on my discretion, but I must tell you that last night I inadvertently overheard you dressing down your nephew. I regret that I heard some secrets that are none of my business." My uncle was stunned, but he soon understood his neighbor's confusion and reassured him as to the state of my testicles.

Uncle Claudio had a housekeeper, Annetta, who came from Urbania, in the Marche, and had been brought up by my grandmother. She was practically a member of our family, always ready to help in case of trouble. She died in my uncle's home and was replaced by her niece.

My Uncle Gino was a professor of Roman law. He had followed the usual career of an Italian university professor, passing from less important schools to more famous ones: Camerino, Sassari, Parma, and, ultimately, Turin. In his profession he had an international reputation, as I can confirm from an incident that occurred to me in Berkeley almost twenty years after his death. One rainy night, I was in the Faculty Club at the University of California and chanced to hear a distinguished gentleman who was Regius professor of law at Cambridge University in England telephoning a Berkeley law professor who was a friend of mine to apologize for being late for dinner because the weather made it difficult to find transportation. I introduced myself and volunteered to take him to my friend's home. He thanked me and said: "Ah! So you are the famous Segrè!" I felt flattered and assented, but he looked at me in a strange way, and I understood at once what he was thinking. For him, the famous Segrè was my uncle, and the ages did not jibe, because my uncle would have been about 100 years old. The worthy gentleman was disappointed, as Poincaré had been with my uncle Claudio.

Gino Segrè was unassuming and even timid, a disposition by reason of which he remained a little less famous, less well paid, and less honored than he deserved and wished to be. He often wrote important legal opinions for famous lawyers, who praised him highly, but paid him little, while they used his work in their briefs and collected fat fees themselves. My father successfully employed his brother in some difficult legal cases and always chided him about his low fees. A high school in Turin is named after Gino Segrè.

One's first impression of him was of a somewhat short man, lean, with an aquiline nose, luminous, impressive blue eyes, a high forehead, and a small blond, singed mustache, with half a cigarette in his mouth. I say "half" because he cut his cigarettes in two before smoking them and thus always burned his mustache. He had a strong constitution and liked gymnastics. In his familiar conversation you could hear the traces of his native dialect. Of course, in lecturing he used standard Italian, but when there was something he did not like he reverted to dialect to say, "Pias mia" (I don't like it).

When he came to Rome from Turin in the course of his official duties, his arrival was a joyous occasion for his two brothers, his sisterin-law, and his nephews. He had a room of his own in our house, with a bookcase containing the Corpus juris civilis and other ponderous Roman law texts in Latin. He could not live without them.

My uncle was frequently summoned to Rome, because both his colleagues and the government had very early discovered that when there was difficult work to do, requiring steadfast application, fairness, and acumen, and especially if it was not paid, Gino Segrè was the person to call for. His presence guaranteed success. Thus, for instance, although it was known that he was cool to the Fascist regime, the government entrusted him with heavy burdens in reforming the Italian Civil Code. He would explain to me, a young boy, the rationale for many sections of the Civil Code—for instance, the section on inheritance—and why it was fair to write the law in a certain way rather than in another.

As a boy, I lacked any special interest in the law or in history, and most of the dead classicism we learned in high school seemed a boring waste of time to me. Not so walks in the Roman Forum with my uncle. His detailed explanations of family relations in ancient Rome, their Latin names and legal implications, were sometimes a little ponderous, but he truly enlivened Roman ruins, inscriptions, and statues with the deep knowledge and familiarity of a person who had really mastered their history. To go with him to the Forum was like taking a walk with a learned ancient Roman bent on introducing me to his great city. "So and so did this, so and so did that," Uncle Gino would explain, pointing out their monuments or inscriptions. "They were related to each other thus, and these were their motives and interests." I have since had the fortune of meeting other great minds, but the first outstanding scientific personality I encountered was my uncle Gino. From him I had my first impressions of what it means to work with one's head, with absolute honesty, patience, stamina, precision, and devotion to the subject matter. These qualities, together with imagination and analytical ability, are among the requirements for any scientific enterprise.

Although he knew German well and was culturally close to his German colleagues and German science, he always kept a watchful, balanced detachment from German culture. He disliked narrow Italian nationalism as much as he did the subservient admiration for Germany that prevailed in Italy between 1910 and 1940. In politics he was a liberal, and a laicist, essentially in the traditions of the Risorgimento; he had a clear premonition of the future of Fascism, and of its consequences for Italy.

My uncles Claudio and Gino were well known in the Italian intelligentsia. Both were members of the highly selective Accademia nazionale dei Lincei, the Italian national academy, a fact especially remarkable in the case of my uncle Claudio, who had no academic connections.

My father, Giuseppe, never went to college. After finishing high school, he left Bozzolo and moved to the town of Urbania, in the Marche region in Central Italy. There he became an assistant to Count Mattei, the administrator of the properties of the historical family Albani. My father was then about eighteen. At first he learned papermaking and ceramic techniques and, above all, acquired business experience. Later he worked for the famous Ginori ceramics works and for other manufacturers in Civita Castellana, not far from Rome.

In the 1880s, Tivoli's famous waterfalls, which had been painted by artists for centuries, were becoming important sources of power, on a very different scale from the small medieval mills of earlier years. The Società per le forze idrauliche ad usi industriali ed agricoli, a corporation devoted to the utilization of the waters of the river Aniene for power and irrigation, hired the young Giuseppe Segrè as an assistant to its general manager, and when the latter died, my father replaced him. He moved to Tivoli and devoted the corporation primarily to papermaking and the generation of hydroelectric power. The second was limited in scope, and that side of the business was ultimately sold to other companies, but I nonetheless remember spending many hours as a child in the generating plant, where the foreman tried to explain the workings of the generators and transformers to me. Unfortunately, I could never understand him. The foreman had mastered his trade well, but he had had only the most rudimentary formal education and could not communicate his ideas. In this he perhaps resembled, albeit in a modest sense, those great nineteenth-century physicists who ignored formal mathematics.

Papermaking became and remained my father's principal concern for the rest of his life. Slowly he increased his share in the mill. He first leased it through a partnership, in which he was the general partner. Later he transformed the partnership into a corporation, the Società cartiere tiburtine (SCT), of which he was a minority shareholder. In the course of time, he bought out the other shareholders, ultimately becoming the sole stockholder. He devoted years to disentangling relations between the concessionaries of the water rights of the river Aniene. Some of these rights went back to the Middle Ages and formed an extremely complicated legal and technical complex. In 1909 my father and others, with great patience and skill succeeded in persuading all the interested parties to come to an agreement that clarified and settled the situation in modern terms. My father was proud of this achievement, by which I expect he gained some water rights for his company.

My father also took upon himself an unpaid minor burden: the administration of the historic Villa d'Este, whose owner, Archduke Francis Ferdinand, never visited it. The archduke made it a condition that the property should not cost him anything. My father felt a lively responsibility for the preservation of the buildings and fountains, but could raise only very little money for this purpose, mostly from entrance fees. Nevertheless he accomplished the task, with the help of some willing artists, who contributed their work, and of a small but devoted and hard-working band of gardeners and artisans.

My mother's family, the Treves, were from Vercelli, in Piedmont, where my grandfather Marco was born in 1814. In search of better treatment of Jews, he migrated to Florence, where he studied architecture and married. After losing his wife and an infant son, he worked for a time in Paris under Eugène Viollet-le-Duc, Napoleon III's architect. The widower then married my grandmother Elisa Orvieto, who was from a Florentine family, and in 1857 the two settled in Florence. My grandfather's most important architectural work was the Florence synagogue, built by him and the architects Mariano Falcini and Vincenzo Micheli around 1882.[5]

My mother Amelia, born on July 27, 1867, was the youngest and favorite daughter of her austere father. Her formal schooling was limited in its subject matter but not superficial. She learned English well enough to read English novels and other books. In our home at Tivoli there was a good library, mostly literary, in Italian, French, and English.

The Treveses of my grandfather's generation were practicing Jews, and even the next generation would go to the synagogue at least on major holidays. The Segrès on the other hand did not observe any rites, and my mother, after her marriage, abandoned any formal religious practice. She told me only a minimum of biblical stories and the central Jewish prayer, with its monotheistic credo. However, if I was in Florence during some religious festivity, I participated in it with my uncle and cousins. I once was there for Yom Kippur when I was about twelve. On that solemn holiday, one is supposed to fast for twenty-four hours. We all went to the synagogue in the morning. Toward noon I left and, feeling hungry, went to a restaurant to eat. Lo and behold, I found my uncle Guido there! I thought he would pay for my lunch, but he was not pleased to see me and did not appreciate God's joke.

For the purposes of this account, my mother's most important siblings were Jacopo (1860–1912) and Guido (1864–1964).[6] Jacopo evidently had exceptional mathematical talent—at least this is what the famous mathematician Vito Volterra, who had been his friend and schoolmate, told me more than once. However, Jacopo died of syphilis he contracted on a trip around the world undertaken with the poet Angiolo Orvieto, his friend and cousin. He left a modest fortune to his nephews but, in drawing up his will, forgot me. My uncle Claudio was displeased by this omission and told me that he would leave me a special legacy as compensation, which in due course he did. He had not, however, reckoned with his executor, my father. Saying that Uncle Gino's three daughters, Egle, Bice, and Fausta, needed this inheritance more than I did, Father gave them my uncle's whole estate, including my special legacy. All this was done with my agreement, although, knowing my father, I believe that he would have done the same even without it.

My mother's other brother, Guido, studied law. After modest beginnings, he was soon involved in important real estate transactions on behalf of rich relatives. In a major building crisis in 1885, he negotiated default settlements between German capitalists and Italian contractors. He thus started a career as a financial expert that was to take him very far. Eventually, he became president of La Fondiaria, a major insurance company. He died a few days short of his hundredth birthday, and when over ninety was still actively presiding over the board of directors of the Fondiaria.

Guido Treves's wife, Emilia Finzi, who was a very close friend of my mother's, and greatly influenced her, died in 1922 of encephalitis. Guido and Emilia had four children, Silvia (Levi Vidale), Marcella, Marco, and Giuliana (Artom); these cousins were very close to me during my early years.

My father must have met Guido Treves on business. Father, who was then twenty-nine, was looking for a suitable bride, and Guido introduced him to his sister Amelia. They must have been favorably impressed with each other, because soon they were engaged.

My father traveled a great deal on business; his letters mention Pesaro, Pisa, Milan, Naples, Florence, and frequent commuting between Rome and Tivoli. Probably they deeply impressed my mother, who had lived in a protected and rather closed circle. The letters may also have frightened her slightly, because they intimated that the impending marriage would bring great changes in her habits and life-style. My father describes the comfortable and attractive home he was preparing for his bride (it even had running water in the kitchen!), the beauty of the location, and the view of the Roman Campagna.

My parents were married on July 7, 1889. Immediately after the wedding, my father brought his bride to the Villini Arnaldi quarter of Tivoli, where he leased a villa called Villino B Maria, which he eventually bought in 1920.

The house had three floors; for many years we occupied the first floor and some rooms on the top floor. Later, we took over the whole house. In my childhood we lived in the first floor. My father converted half of a large terrace into a bathroom, next to the master bedroom, with a zinc bathtub and primitive but adequate washing facilities. If bathrooms in Tivoli were not common, the city was among the first in the world to acquire electric light, with carbon filament bulbs that gave a reddish hue; at the time, they still used acetylene lamps in my uncle's house near Florence.

The Tivoli of my childhood was very different from the presentday city. Around 1915, Tivoli had a population of about sixteen thousand, confined in a town that had not changed very much since the Middle Ages. We lived in a new development, consisting of about a dozen houses on the slope of Mount Ripoli, outside of town, at the start of a country road that followed the hills at mid level among the olive groves, leading to villages and farms a few miles away. Between the houses there was a rustic park, well laid out with olives, plane trees, lilacs, and acacias. The three lowest houses, one of which was ours, overlooked the Viale Carciano, with a superb view of the Roman Campagna, at that time largely wild. The dome of St. Peter's in Rome was a mere bubble on the horizon. In between, the plain was crossed by the Aniene River, whose course was flagged by a prominent landmark: the large cylindrical mausoleum of the Plautii, dating from the early Roman empire. About a mile to the left of the river, one saw the dark cypress trees and ruins of the emperor Hadrian's villa. On the right side of the plain, there were two large hills, crowned by the Sabine villages of Montecelio and St. Angelo. Closer by, the eye rested on the silver gray of the olive trees covering the hill on which Tivoli itself was built. It was a stunning view, which changed vastly according to the hour, season, and weather conditions.

The Viale below our house was shaded by big elm trees, and in the fall the elm leaves formed a golden rug on the roadway. The wind made them swirl and sometimes heaped them up before blowing them away. I can still in my imagination smell the dry leaves and fresh rain. The stretch used by the people of Tivoli for the traditional promenade was still rustic, without sidewalks. Almost exactly below our house there was a small chapel with a Madonna, to whom the people of Tivoli addressed prayers. I remember crowds of shawl-wrapped women imploring the Madonna to keep Italy out of World War I. Soon thereafter the avenue was used for basic training of recruits destined for that war. Many of the soldiers had white handkerchiefs tied to their right arms to help them distinguish right from left.

At home the cooking was done on charcoal stoves. The food was very simple, but very good. Boiled meat, roasts, vegetable soups, peppers, and all greens in season: tomatoes, endive, eggplants, chicory, string beans, zucchini, squash, peas, and many other vegetables. The excellent bread, baked at home once a week, was dark; in addition we ate rice and a little homemade pasta. For the holidays, both Catholic and Jewish, there were other delicious dishes, often of Jewish origin, passed down through Uncle Claudio's housekeeper Annetta from my paternal grandmother. The coffee was always very weak because my mother liked it so: our home was notorious for it. All told, the food was not very varied, but wholesome and tasty. When I was about twenty and stayed at Tivoli either alone or with some friend to prepare for exams, the old caretaker, a maid trained by my mother, prepared the same fare for us: broth, boiled beef, roasted peppers, fruit. We loved it.

Many of the things we buy in shops nowadays were made to order: shoes by the shoemaker, my clothes by a seamstress, and so on. Needless to say, there were no automobiles; when we needed to, we rented a horse-drawn carriage.

Tivoli was linked to Rome by the railroad, which was used by Uncle Claudio, who visited us almost every weekend, and by a steam tramway, which was a little more rapid and convenient. The tram ran from Porta San Lorenzo in Rome and followed the Via Tiburtina, reaching the terminus in Tivoli, a five-minute walk from our house, in about an hour. The last two miles were quite steep, and the engine made loud noises.

Today (1987) the landscape has been devastated. The destruction is appalling: carelessness, speculative greed, and plain incompetence have destroyed most of the beauty of the place.

At the time of my birth, in 1905, the success of the paper mill was established and our family was, if not rich, more than comfortable. My parents had started traveling abroad and, among other trips, had been to England for the coronation of King Edward VII as guests of a London customer who bought cigarette paper from my father.

My first recollections go back to 1908: a red belt, certain striped socks, the Kodak camera of my brother Marco, a Japanese costume given to me by my uncle Jacopo Treves. Around that time my parents hired an Austrian nanny for me. She had a beard and had had an unlucky love affair with her brother-in-law, who belonged to an elite Austrian Alpine regiment. After lunch she repaired to her room on the upper floor of our house; she smoked strong cigars and sometimes drank cognac in her room. She loved me dearly, and her affection was fully reciprocated; she taught me many things, taking them from an illustrated encyclopedia, whose pictures, including those of tortures, occupied me for many hours. This Nanny, whom I called Tata, took me to the public gardens to play, and if anyone tried to kiss me, she would say severely, "Non si paciano i pampini" (One does not kiss children) with a strong Austrian accent. From her I learned German for the first time, but later I forgot it.

When I was about five years old, my mother taught me to read, and shortly afterward, my parents hired a young teacher for my private instruction. Signorina Maggini had just graduated from a teachers' training college, and I was her first pupil. She taught me with great enthusiasm and according to the latest educational theories she had learned at school. Besides reading and writing and the other usual subjects of the first grades (she was not too demanding on the Pythagorean table), she often took me hiking in the hills behind Tivoli. She would buy a one-penny tablet of Tobler chocolate, which had pictures I collected, and then we walked for a couple of hours in the hills. During those walks she taught me history, natural history, poetry, civics, and so on. I had an excellent memory and greatly enjoyed learning things such as the physiology of digestion, illustrated by the experiment of chewing a piece of bread until it became sweet through the action of the enzyme ptyalin on starch. I believe I was a rather extraordinary pupil, but since she had no experience and did not know what to expect of a child of six, she attributed everything to "family background." Later, with my own children, I often recalled the teachings of Signorina Maggini, with whom I remained friends until her death in 1971.

At the same time, my parents sent me to public school, mainly so that I would have the society of other children. It took me five minutes to walk from home to school, and I went alone from the very first. At the beginning of the town, the road crossed a pass often swept in winter by a bitterly cold wind. I would wrap myself in my hooded cloak and run as fast as I could past the critical spot.

Family strolls on the Carciano road were a firm habit; during the winter, my parents and I invariably used to take a walk there from about 2 to 4 P.M. On these strolls, when it was cold, as it usually was in winter, my mother wore a skunk fur and muff that preserved a slight skunk scent, which I liked and associated with her. My nose is thus imprinted on the skunk odor, and I still like it. Very often we were joined in our walks by Count Luigi Pusterla and his wife Emilia, my parents' closest friends in Tivoli. He was a handsome old gentleman with a white beard, a painter by profession. Count and Countess Pusterla lived in an eighteenth-century family palazzo in the center of Tivoli, but had very little money; the count worked as an agent of the Italian State Lottery. He jokingly called himself a "seller of nonsense on behalf of the state." In his palace he had beautiful old furniture, a good library, and a great number of rooms, which he had covered with frescoes illustrating Garibaldi's deeds. As was customary in the eighteenth century, all the rooms of the palace were in a row, allowing me to run from one end to the other. I regularly tripped at each threshold, and Pusterla took pity on me and ordered all the thresholds to be leveled so that I would not fall. When years later I saw the palace of the great poet Leopardi in Recanati, I was struck by its resemblance to the Pusterla palace, extending even to the books in the library. When I visited them, Count Pusterla would often make pencil drawings for me and help me to color them, to my great delight. He had a good classical education and spoke so much of the ancient Romans that I, seeing his white beard, asked him if he had lived in those days.

Pusterla was a liberal nourished in the ideas of the Risorgimento, the political movement that brought about the liberalization and unification of Italy. He was against any secular activity by the Catholic Church, admired Garibaldi and his movement, and had great faith in progress, education, and the future. He had introduced my parents to the idea, if not to the practice, of mountaineering and in general to love of the outdoors and of natural beauty. My parents and the Pusterlas shared a deep and devoted friendship; the Pusterlas often came for dinner at our house, and we saw each other almost daily. Luigi Pusterla was fortunate in dying shortly before the beginning of World War I; his widow survived him for many years and remained intimate with my mother.

Another member of the small world of Tivoli was Dr. Natale Allegri, an old-fashioned physician who knew more Latin than medicine, but treated his patients with great devotion and goodness of heart. He was a generous soul and secretly helped the poor, although he was poor himself. He, too, was often a welcome dinner guest and always ate two eggs sunny-side up. He died during the influenza epidemic of 1917 and was universally mourned. Dr. Allegri cured our minor ailments. If there was something serious, we consulted Dr. Parrozzani, the chief of staff of the Tivoli Hospital, and a superior surgeon, who remained all his life in Tivoli because of an unhappy family situation. Dr. Allegri gave me a small tortoise, which I called Crocrò and tamed so that it would "run" to eat salad or cherries out of my hand. Crocrò used to hibernate underground in some flowerpot on our terrace.

Tivoli also had a national college and a ginnasio liceo (classical high school). Several of the professors in this high school were distinguished in their field. The botanist Lino Vaccari, an authority on Alpine plants, is still quoted in current literature. The teacher of Italian literature, Chiarini, had been a pupil of the important poet Giosuè Carducci and was well known as a critic. The musicologist Radiciotti (grandfather of the distinguished physicist Marcello Conversi, who was born at Tivoli in 1917) was an internationally recognized authority on Rossini. These people were not isolated from the rest of the world. They read and talked about current literature, and had relations with artists, some famous, who came to Tivoli. If, in the kitchen of the Pusterla palace, there was an inscription on the hearth "Vivitur exiguo melius" (One lives better with little), perhaps a consolation for the frugality, not totally voluntary, of the meals, in their parlor they had a beautiful concert piano, on which Liszt had played during his vacations, when he spent the summer at the Villa d'Este as a guest of Cardinal Hohenlohe. The poet Gabriele d'Annunzio, the painter Michetti, and the sculptor Costantino Barbella formed a trio of artists originating from the Abruzzi region who frequented Tivoli. The painters Ettore Roesler Franz,[7] Onorato Carlandi, and others from foreign countries often came to Tivoli, and my parents knew most of them. The fact that my father was in charge of the Villa d'Este helped us make contact, because the artists often worked there.

During the summer, my mother and some friends spent the mornings sewing in the shade on the central balcony of the villa, which had a magnificent view of its park and of the Campagna Romana. I too played in the park of the villa, together with the son of the gardener. Once my friend and I found out that a movie company had prepared a great scene involving fireworks for some film they were shooting. To signal when to let off the fireworks, they had hidden a Bengal light behind a tree, which we set off—needless to say at the wrong time, but innocently enough, I believe—with consequences that may easily be imagined. This was not my only adventure with fireworks. When I was about ten years old, I stuffed some sulfur, potassium chlorate, and charcoal into a bamboo cane and lit it. Luckily, I was not killed, but the tremendous explosion ended my playing with fireworks.

During the summer, I often went with Signorina Maggini to Acque Albule, a sulfur spa about eight miles from Tivoli, on the road to Rome. However, I learned to swim only when I was about twelve years old, at the seashore. At Acque Albule, I met and made friends with a young Australian priest, John Leyden, who gave me a most interesting book in English called The Handy Boy , which taught me how to build toys, airplane models, telegraphic apparatus, and so on. He also gave me a wonderful French book, La Bannière bleue, which introduced me to the exotic and fantastic world of the Mongols (my mother had started teaching me French shortly after my seventh birthday). After that I read and reread Marco Polo's Il milione . I spent pleasant hours with my friend on the slopes of Monte Ripoli; I believe my parents feared that he would try to convert me to Christianity, but, as far as I remember, the excellent young man never mentioned religion to me.

During the hottest part of the year, we went to the seashore at Viareggio or Forte dei Marmi, where I often found my Segrè or Treves cousins (but very seldom both together). Giuliano Bonfante, the son of a well-known professor of Roman law who was a friend and rival of my uncle Gino's, was my unpleasant playmate. We all lived in a pension in Viareggio, then still rustic and dominated by a famous and then-flourishing pine wood. Once in a while the composer Puccini would appear with his motorboat, and we knew that d'Annunzio had a villa nearby (until he was compelled to flee his creditors). We once went to visit Marconi's radio station at Coltano, and I still remember the noise of the sparks and the appearance of the complex electrical transmitter. Uncle Claudio visited us once in a while for short periods. Otherwise we followed the ordinary seashore routine: bathing, hikes, building canoes or castles of sand, and bellyfuls of grapes. Here my cousin Fausta taught me how to swim; with her I built many sand boats, which we used for imaginary travel.

In September we would move to Marignolle, the Treves villa, near Florence. It is a large building of medieval origin, with sizeable land-holdings, then cultivated by sharecroppers. Olive oil, wine, vegetables, fruit, and some wheat were the main crops. There was also a handsome Italian garden in the grounds of the villa proper. The families Finzi and Treves, each with a large number of boys and girls of similar ages and more or less related to each other, occupied the villa. Once in a while, my parents would go for a vacation abroad and park me at the villa. When I was very young I suffered greatly being separated from my mother. My cousins Silvia and Marcella, who were about twelve years older than I was, tried unsuccessfully to take care of me. They were too prim and Victorian for a slightly wild child. Fortunately for me, I had never had an English governess like the Treves children. Despite their strict upbringing, my older cousins once organized a wonderful game. We smaller children, who were about twelve years old, had created a postal system for ourselves. It had its little letters, stamps, deliveries, and so on, and we enjoyed writing to each other. At a certain point, we started receiving mysterious communications commanding us to collect various objects and to bring them to preassigned places, with injunctions of strict secrecy. One night the messages, which we had scrupulously kept secret, called us to a fishpond that was in the territory of the villa. We all arrived there after overcoming several obstacles, such as masked enemies opposing our progress, and at the appointed place we found a feast, with fireworks, organized by the older girls, Silvia and Marcella.

I am unable to identify the earliest origins of my interest in physics. My first memories having some connection with physics have to do with tools and a camera belonging to my brothers. I called the camera a "mappa sciafa" (the correct term is màcchina fotogràfica ), because I did not yet speak well. Later, at home, I must have heard talk about scientific or technical subjects, and as soon as I learned to read I got hold of books about science such as Tissandier's Le ricreazioni scientifiche (Scientific recreations)[8] and popular scientific magazines. I still have a notebook dated March 27, 1912, entitled "Physics," in which, in the handwriting of a seven-year-old boy, and with some misspellings, I describe the simple experiments I performed, possibly having read of them in Tissandier. My mother helped me in drawing the figures with which I illustrated the notebook. Colors such as those produced by the refraction of sunlight in a pitcher of water especially fascinated me.

A little later, my brother Marco, who was preparing for a chemistry examination at the university, bought chemicals at a local drugstore and repeated many of the experiments mentioned in his textbook at home. He allowed me to watch him, and I was completely enthralled by the color changes that I saw happening in his test tubes.

Uncle Claudio took me to visit his own institute, where for the first time I saw a real scientific laboratory, with all kinds of apparatus. My uncle also gave me an old physics text by A. Ganot, printed in 1863, in which, among other subjects, I found mention of "the recent experiments by Mr. Faraday."[9] This book became my constant companion, together with the history of France by Victor Duruy, which was given to me by my mother. A few years later, on November 21, 1916, seeing my interest in physics, Uncle Claudio gave me a 1913 French edition of Ganot's book.[10] On the flyleaf he wrote: "To my beloved nephew, with the wish that soon physics will serve the arts of Peace, Uncle Claudio." At the Pusterla house I also found a book by J. B. Dumas, from which I learned the composition of, and the difference between, sulphites, sulphides, and sulphates and similar facts of inorganic chemistry. I also admiringly read Faraday's Chemical History of a Candle .

I have a book, "For when I shall be grown up," in which one was supposed to write answers to questions about oneself. In it, I wrote as my wish for the future that I wanted to become a physico-chemist and die at thirty in the explosion of my laboratory.

All told, I had a happy childhood and was much cared for by my mother (less so by my father, who did not pay much attention to me). Needless to say, I also experienced my share of childhood scares and terrors. One day I read the vivid description of the famous plague in Alessandro Manzoni's classic novel I promessi sposi . As usual, I slept alone on the upper floor of our Tivoli house and, in the darkness, I was overwhelmed by fear of catching the plague. I was reluctant to get up and go to my parents on the lower floor to tell them of my fears, but finally I did. They calmed me down without making fun of me in any way.

From Tivoli I was brought once in a while to Rome. On these occasions we lunched at Uncle Claudio's, returning home in the evening. I remember the 1911 Exposition commemorating fifty years of Italian unity and its interesting regional ethnographic exhibits, as well as flying airplanes. On one of these trips, my parents took me to a puppet show, which delighted me, and for days I kept imitating Caliban. Without knowing it, I had seen a Podrecca production of Shakespeare's The Tempest , a classic still famous in puppet art, which revealed all the splendor of the original play.

When I was ten years old, I fell seriously ill with scarlet fever, complicated by nephritis. I was in mortal danger, and my mother took care of me day and night, with the help of Annetta. At the time there were no specific treatments for streptococcal infections. I was kept in bed for a couple of months on a milk diet. While I was ill my mother read me several books by Jules Verne, and Uncle Claudio gave me a mineral collection and a Brownie camera, which I learned to use, developing and printing my own pictures. An engineer who often worked for the paper mill gave me a Ruhmkorff coil, with which I performed many experiments as soon as I recovered. I also built myself a galvanometer, batteries, and other electrical apparatus.

After my bout with scarlet fever I remained susceptible to serious allergies, in which my skin peeled off and I had other symptoms closely resembling those of scarlet fever, except that I did not get nephritis (I checked by myself, testing my urine for albumin). This recurring "scarlet fever" came back almost every year until 1926, after which it disappeared. It was peculiar enough to have me reported in the medical literature. The last time I got it, I was skiing at Clavières and the doctors wanted to isolate me as contagious; later the professor at the medical school in Turin sent me to his former teacher, Frugoni, in Florence, and the latter's assistant, Giacomo Ancona, took my history. Many years later, Ancona and I met again in California as refugees and became very close friends. In 1948 I retrieved my medical history from Frugoni's archives; he had invited me to dinner in Rome, and when I reminded him that he had visited me in 1926, he found my papers in a couple of minutes!

I finished elementary school flunking Italian composition, but passed on a second try and entered the ginnasio at Tivoli. Of that school I remember an odd teacher of mathematics; he used to walk all alone on the Viale Carciano dressed in a morning coat, speaking to himself. This fellow told me that I did not understand any mathematics and gave me a flunking grade. I worried about it, but my parents sent me to a private tutor who was an excellent mathematics teacher. He gave me a few lessons and taught me the fundamental rule that a fraction does not change on multiplying numerator and denominator by the same number. Thus in a couple of hours he fixed my mathematics and told me that I did not need further coaching. As a bonus he taught me a little game in which each of two players alternately names a number between one and ten; the numbers are added together, and whoever succeeds in reaching 100 first wins. This teacher encouraged me and was of real help to me.

As my parents' youngest child by several years, I believe I was treated differently from my brothers. At the time of my birth, my father was forty-six, my mother thirty-seven. This must have influenced their attitude toward me. As a child, of course, I did not see this, but thinking it over now, it seems obvious to me.

In 1917, during the war, we moved from Tivoli to Rome, which produced a great change in our family's way of life. Business increasingly required my father's presence in Rome, and the day-to-day management of the paper mill could be entrusted to a technical director. Traveling back and forth between Tivoli and Rome was tiring, and my father suffered an angina attack. Scared, he consulted a noted doctor in Rome, who told him to set his affairs in order because he might die any moment. (My father lived over thirty years longer and, with a certain perverse glee, attended the funeral of the doctor he had consulted.) The physicians in Tivoli, Dr. Allegri and others, tried to minimize the importance of the episode, and they were clearly right. However, objectively, the center of my father's work had shifted from Tivoli to Rome.

Just then, a cardinal who lived on the floor below Uncle Claudio died; the apartment he left was large enough both for our family and for the business office of the paper mill. We had already spent a few months at a pension in Rome with a view to moving there permanently, and this finally decided us.

Both my Mother and I deeply regretted leaving Tivoli. For my part, I hated leaving my open air games and my old friends, as well as the space we had at home in Tivoli for my experiments. But the move to Rome, the end of World War I, and the new high school I now began to attend signaled the end of my childhood. I was twelve years old, and many things in me had started to change.

My mother had great difficulty in getting adjusted to life in Rome. All her friends were in Tivoli, where she had lived for almost thirty years. Life there suited her; she loved the freedom of the country. To cheer her up, my father kept the lease of our Tivoli house (later he bought it outright), and as a consolation we spent long periods in the spring and fall there. Perhaps it is not without significance, however, that there is a street in Tivoli named after Amelia Segrè, in part because of her tragic end as a martyr of the Nazis, in part because of the fond memories she left, but not one named after my father, Giuseppe Segrè, who did so much for the welfare of the city.

Chapter Two—Discovering the World: Rome and High School (1917–1922):
Scent of Florentine Wisteria

Che pensieri soavi,
Che speranze, che cori, o Silvia mia!
Quale allor ci apparia
La vita umana e il fato!

(What tender thoughts,
What hopes, what hearts, O Silvia mine!
How human life and fate
Seemed to us then!)
Giacomo Leopardi, "A Silvia" (trans. Arturo Vivante)

The move to Rome signaled the start of a second period of my life. I was no longer a child, and the change in residence happened to coincide with the onset of puberty. New feelings, new interests came to the fore. I started to see a wider world, to appreciate poetry, to recognize the beauty of intellectual constructions. It was a cloudy, not a happy period. I was confronted with new, seemingly dreadful problems, and I did not know how to cope with them or whom to turn to for help.

At Rome I was enrolled in the Ginnasio Mamiani, located in a palace next door to our home on Corso Vittorio. I hardly remember the teachers of the early classes. Soon I started taking some extra books in which I was interested with me to school in order to have something to read if classes became too boring. Usually the teachers let it pass, provided I did not disturb anybody. I got hold of a book on elementary geometry and amused myself in solving its problems, more or less as I would have solved crossword puzzles.

As usual, we spent the summer of 1918 in Tivoli; in the fall, the dreadful influenza epidemics of the previous year recurred; I, however, had already had the disease in 1917, without knowing what it was. We lingered in Tivoli, and in order not to waste too much time, I started translating Ovid's Metamorphoses , which was required reading for the coming school year, on my own. In that solitary fall at Tivoli, under the influence of this strange text, I felt poetic emotions for the first time. It was a period of deep upsets, certainly connected with puberty, and it left its marks on me.

All told, I remember my ginnasio years as rather boring. I did not learn much Latin or Greek. I was taught mathematics with a misplaced rigor, under the influence of the great mathematician Giuseppe Peano, but without adequate practical exercises. As my studies progressed, however, the teachers became of better quality. After five years I passed from ginnasio to liceo, where I spent three more years.

In the liceo, a Professor Rua tried to teach us, through sparse but appropriate remarks, what it meant to write well in Italian (and perhaps in any other language). He debunked the empty rhetoric of several of my schoolmates, derived from misguided imitation of writers such as the poet Giosuè Carducci (1835–1907) and d'Annunzio. He told us that if we succeeded in having one or two ideas and in explaining them clearly and concisely, we would write good essays and get high marks. Attempts to substitute even modest thoughts with empty words would be poor writing and earn low grades. Once I learned these simple rules, I started a small essay factory, not only for myself, but also for my cousins and friends. I produced them without effort and with good success. Professor Rua also said that had we been good writers, our styles would have resembled those of the great authors we studied. To me he assigned Leopardi.

The Latin and Greek teachers succeeded only in boring and disgusting me with their subjects. The professor of French, M. Grimod, a native Frenchman, was excellent, however, and seeing that unlike my schoolmates, I knew the language, he let me get acquainted with French literature without bothering to teach me all the subtleties of French grammar. An excellent anthology he had compiled helped me greatly to appreciate French writers.

Of history we learned only dates, without any sense.

Professor Monti in physics inculcated in me F = ma until I really understood its meaning. He thought that one should teach few notions, but thoroughly. This was a very healthy attitude, which did not prevent him from explaining even some relativity. Einstein was fashionable in those days.

The mathematics professor drove me crazy with Dedekind cuts. I learned rigorous proofs of seemingly obvious things, useless at my level, and at a time when with a little effort, I could have learned calculus, which would have been invaluable to me. On my own I read sections of Enriques's Collectanea, an encyclopedia of elementary mathematics seen from a higher point of view, and some number theory. I regret the effort spent in those years, so important for learning, on non-Euclidean geometry, number theory, and other subjects, completely omitting applied mathematics. At home there were books on analytic geometry, algebra, and calculus that had been used as texts by my brothers at engineering school, but my brother Marco locked them up and forbade me to use them, on the pretext that they would "tire my head." In fact, he wanted to remain the only one at home to know "Il càlcolo sublime, " as he called simple infinitesimal calculus.

Being so much older than I was, my brothers Angelo and Marco virtually belonged to a different generation and were already at the university when I was barely learning to read. Angelo had been a difficult child, and Uncle Claudio frequently recounted his deeds. For instance, in a railroad compartment, he had insisted on being put on a baggage net above the passengers and, once there, used his vantage point to pee on those below him.

In 1911 Angelo volunteered for the army to satisfy his military obligations, but almost immediately came down with a serious case of pneumonia, from which he barely recovered. He was discharged from the army on health grounds and thereafter started a life of travels, strange adventures, and general disorientation that created serious problems for my parents, who did not know how to cope with him. Before joining the army, Angelo had started studying engineering, and he developed a passion for mathematics and physics, although he was not especially proficient in either. As a boy he had acquired a vast literary culture in Italian, French, German, English, and Spanish, which he mastered, as well as in classical Latin and Greek. The library he left at home when he went away was a great source of reading material for me.

Angelo did not like Tivoli and, especially in his early years, wanted to stay away from his parents and be independent. However, when he landed in trouble or fell ill, somebody, usually Uncle Claudio, had to come to his rescue. Ultimately, my parents unloaded him on Uncle Gino, who had a good opinion of the uncommon intelligence of his nephew and was not as close to him as my parents. Appreciating Angelo's talents, Uncle Gino downplayed his eccentricities and trained him with infinite patience in law and history. After this schooling by his uncle, Angelo studied with the noted philologist Gerolamo Vitelli, who introduced him to papyrology, and also with the historian Gaetano de Sanctis. Subsequently he went to Germany, where he worked with local historians and had an adventurous and somewhat nomadic life. In Germany he met Katja Schall (1899–1987), whom he married in 1936. About 1930 he won a university chair in economic history at Catania, in Sicily. He then started painting but refused to exhibit his work. More of him later.

Angelo disliked and despised his brother Marco, who reciprocated his feelings. The younger brother, although less intelligent, and something of a hypocrite, was often extolled as an example by our parents. They clearly favored him, because he gave them fewer problems. Marco on his side always tried to point out Angelo's weaknesses and to embarrass him. "There is no point in worrying about Angelo; he does not have the courage to get himself into serious trouble!" he would say.

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Chapter Ten—Triumphs and Tragedies (1954–1982):
Odor of Laurel and Cypress

Ehret die Frauen! Sie flechten und weben
Himmlische Rosen ins irdische Leben.

Honor to Woman! To her it is given
To garden the earth with the roses of heaven.
Schiller, "Würde der Frauen"[1]

I had been invited more than once to lecture in Brazil, in part through G.C. Lattes, who had helped detect the first pions formed by the Berkeley synchrocyclotron. In 1954 the time seemed ripe for a visit to Rio de Janeiro. Our children were too young either to take along on such a trip or to leave alone, so I went to Brazil by myself that July while Elfriede stayed behind with them in Berkeley. When the Jenkinses heard of our predicament, however, they offered to take care of the children for a while, giving us yet another reason to be grateful to them, and Elfriede was able to join me in August.

Brazil fascinated me. I am hard put to describe, let alone explain, my feelings toward my exotic, but at the same time almost familiar, new surroundings. The novel tropical beauty, nostalgic reminders of the colonial period, my affection for Dom Pedro and his well-ordered empire, and the behavior of the people formed a mix most agreeable to me. We also liked the food, the exotic fruits, and the many kinds of bananas. Furthermore, we found excellent company: Georg von Hevesy, with whom we often spent the morning walking on the Copacabana beach; G. P. Thomson, who was lecturing at the same institution as I was, and Lattes himself. Almirante Alvaro, chief of the Conselho de pesquisas físicas, entertained us at the Bosque Tijuca, where he planted a tree in my honor and recited poems by Camoëns.

Guido Beck, an Austrian physicist whom I knew from my time in Rome, helped immensely in guiding me in the new strange world of Latin America. Among other things, he found a way of getting us a visa for Peru, which we did not know we needed. When we asked for it, much to our surprise, Elfriede was refused and declared "peligrosa a la seguridad nacional del Peru." It was because she had been born at Ostrowo, which in the meantime had become part of Poland and thus was behind the Iron Curtain. Our friend ultimately succeeded in obtaining the visa through personal intervention, but not without a few comic scenes. A Peruvian professor helped me materially, and I ended up becoming an honorary professor of San Marcos University in Lima.

From Brazil we went to Uruguay, where we stayed with my dear cousin Riccardo Rimini, and then to Argentina, which was under the Perón dictatorship. The slogan "Perón cumple y Evita dignifica" (Perón delivers and Evita dignifies) was everywhere, evoking somewhat cynical comments, which we naturally kept to ourselves. In Argentina we visited several Italian émigrés, some physicists, some not, whom we had known before our own emigration.

The last leg of our trip took us to Peru, a country we found extremely attractive owing both to its peculiar natural beauty and to its Indian culture. We were wise enough to allot sufficient time for sightseeing to allow us to gain a real impression of this beautiful world, so different from anything we had seen before. We flew from Lima to Cuzco in an unpressurized airplane. We wore oxygen masks but I took mine off in opening a window to snap a picture of the Andes. I barely made it back to my seat, where I fainted briefly, while Elfriede put the mask back on my face. We remained at Cuzco for a few days to acclimatize ourselves to the altitude and see the Inca monuments, then descended to Macchu Picchu, where we spent the night. Next day we climbed Vaina Picchu by the very steep stairway hewn from the rock by the Indians, under a tangle of orchids.

On October 8, 1954, shortly after our return, while I was resuming my regular routine, I had a telephone call from Chicago. The caller was Sam Allison, and from his tone of voice, I realized at once that he had very bad news. From his almost incoherent words, I gathered that Fermi had been operated on shortly before, and that the surgeon had found an incurable stomach cancer. I was stunned. When I had seen Fermi in February, I had noticed that he looked a little tired, but it did not cross my mind that there was anything to worry about. During the summer, Fermi had gone to Italy and we to South America; we had not been in touch. In Italy, he had begun to feel seriously ill, and as soon as he returned to Chicago, he went to Billings Hospital. The first doctor who saw him, an intern, did not make the correct diagnosis, but the chief surgeon shortly thereafter performed an exploratory operation and found a hopeless situation.

As soon as possible after hearing the news, I caught a plane to Chicago. I found Fermi at Billings Hospital, fed by a tube that ran directly into his stomach. The patient was measuring the flow of the fluid by counting the drops, using a stopwatch, as though performing a physiology experiment. He was perfectly aware of his condition and started talking about how many months or weeks he might survive, and what he would do in the short span still allotted him. He asked me to summon Edward Teller to see him, adding with a slightly ironical smile, "What nobler deed for a dying man than to try to save a soul?" Fermi thought that Teller's behavior in connection with the hydrogen bomb and in the Oppenheimer hearings had been reprehensible—among other things, it had split the scientific community into factions—and he wanted to make him realize this. "The best thing Teller can do now is to shut up and disappear from the public eye for a long time, in the hope that people may forget him," he added. Needless to say, as soon as I got back to Berkeley, I relayed the summons to Teller, who subsequently went to visit Fermi. Teller has given his own report of this visit.[2]

Fermi then spoke pessimistically about the world's future. Atomic bombs were making possible the destruction of civilization. All it would take for them to be used was for a madman to come to power in a great nation. Since this happened every few centuries, he reckoned that civilization might, with luck, last roughly that long. He said, too, that if he lived long enough and had the strength to do so, his last service to science would be to write down his lectures on nuclear physics, which were preserved only in the form of notes taken by students.[3] This was, in fact, his last effort at scientific writing. In a lighter vein, he told me that he had been blessed by a Catholic priest, a Protestant pastor, and a rabbi. At different times the three had entered his room and demurely and politely asked permission to bless him. He had given it. "It pleased them and it did not harm me," he added.

We spent several hours talking about various subjects. Among other things, Fermi observed that since his wife, Laura, had just finished her book Atoms in the Family, his death would come at the right moment for promoting it, and that he hoped the literary success he anticipated for it might help her overcome the difficult times she faced.

At the end of the afternoon I left. When I got out of the hospital, I felt ill; the emotional upheaval produced in me by the visit was too much for my constitution. I returned to Berkeley gravely upset, and as soon as possible I went back to Chicago. I found Fermi much worse and in a more somber mode. He spoke of his sufferings and of other subjects I will omit. We talked until late in the evening. During the night, I was awakened by a phone call announcing that Fermi had died. It was November 29, 1954.

I stayed in Chicago for the memorial service at the University of Chicago. Searching for an appropriate text, the university chaplain proposed several that did not seem right. Finally, he suggested St. Francis's "Cantico delle creature" ("The Song of Brother Sun and All His Creatures"). It seemed to fit the occasion, and he used it.

Fermi's unexpected and premature death shook me deeply. Even now Fermi often appears in my dreams. In their grief, his former pupils and friends sought an appropriate memorial. Ultimately, the idea of publishing his collected papers crystallized. The Accademia dei Lincei and the University of Chicago Press undertook to do so and appointed me chairman of the editorial committee.[4]

In 1955 we moved from Berkeley to Lafayette, a suburban community about ten miles east of Berkeley, behind the coastal hills. Our new house was on a dead-end road on a hill; the address was 36 Crest Road. It had been part of a large estate, had a beautiful view, and was in a most attractive natural setting.

During my lifetime I came to love three homes in particular. The one in Tivoli, the Treves villa at Marignolle, and our house on Crest Road in Lafayette. Naturally, I remember the others—229 Corso Vittorio at Rome, my apartment in Palermo, 1617 Spruce Steet at Berkeley—but I do not have a special attachment to them, and I do not dream of them at night.

I loved the Tivoli house where I was born, because I spent my childhood there. Conflict with Marco separated me from it, but much more serious has been the deterioration of the surroundings. The Tivoli of my childhood does not exist anymore, and even if the walls of the house are still there, all the rest is gone: landscape, roads, gardens, neighborhood.

Marignolle was never my home except during summer visits. The place struggles to survive the changes in the Treves family. Those of my generation have almost become slaves of the villa, while those of the next will be hard put to maintain its spirit. Irresistible forces have transformed the agriculture, the society, and even the face of Tuscany.

Geology drove me from 36 Crest Road, the house I loved best in the United States. When I bought it, I did not realize the serious geological problems affecting the location, nor the importance of a lower lot, which was also for sale at the time, to its stability. I never thought that somebody might want to build on that lot, because it was manifestly foolhardy to do so. The surroundings of the place were also different from what they are now. There was no Highway 24, and the area now occupied by a church was a beautiful meadow with a few old oak trees. The church in due course destroyed the beautiful setting to create parking lots and make money, which convinced me that it was an enemy of God and His works. Furthermore, in 1956 somebody bought the lot below my house mentioned above, and without my becoming aware of it, obtained a building permit. When I saw the new owner of the lot excavating the slope in an obviously dangerous way, I warned him and took photographs of the terrain, but I did not start a legal action, which I would possibly have lost. During the winter of 1958, heavy rains caused a slide on the excavated slope.

This neighbor, in 1960, sued us because the slide he had provoked had damaged his house! We countersued him, and he lost, but the damages awarded to us paid only part of the cost of a retaining wall we had to build to stabilize the slope; nor did they compensate for the depreciation of our property, not to mention the time lost and the anguish caused to us. In practice we never succeeded in repairing the damage satisfactorily. Ultimately, in 1978, we sold the house for much less than it would have fetched without its history.

I grasped too late the type of house I would like; furthermore, my ideal home has contradictory elements in it and hence may not exist. I like a country setting, but I never really enjoyed gardening; I like a well-finished house, but I am not a handyman. All told, Adalbert von Chamisso's poem "Schloss Boncourt," mourning the demolition of his childhood home, perhaps best reflects my feelings:

Ich traüm' als Kind mich zurücke
Und schüttle mein greises Haupt;
Wie sucht ihr mich heim, ihr Bilder,
Die lang ich vergessen geglaubt!

Hoch ragt aus schatt'gen Gehegen
Ein schimmerndes Schloß hervor;
Ich kenne die Türme, die Zinnen,
Die steinerne Brücke, das Tor.

Es schauen wom Wappenschilde
Die Löwen so traulich mich an,

Ich grüsse die alten Bekannten
Und eile den Burghof hinan.
. . . . . . . . . . . . . .
So stehst du, o Schloß meiner Väter,
Mir treu and fest in dem Sinn,
Und bist von der Erde verschwunden,
Der Pflug nun über dich führt.[5]

Back to physics! The problem of the existence of antiparticles arose in 1928 with Dirac's relativistic theory of the electron. This theory gave solutions that corresponded to a then-unknown stable particle of the same mass and spin, but opposite charge and magnetic moment, in other words a positive electron. This particle was called the antiparticle of the electron, or positron. At the time of Dirac's prediction, the positron was unknown, and its absence was considered a serious flaw in Dirac's theory. Dirac, as a last resort, tried to identify the positive electron with the proton, but this proved untenable.

Things changed radically with C. D. Anderson's discovery of the positron in cosmic rays in 1932. (The prediction of the positron is one of the triumphs of Dirac's theory.) The notion of antiparticles was generalized into the postulate that every particle has its own antiparticle. In the case of neutral particles, particle and antiparticle may coincide.

The extension of Dirac's theory predicting antiprotons was very plausible, but not certain. Furthermore, most physicists were surprised when, around 1931, Otto Stern measured the magnetic moment of the proton and found it to be very different from the naive theoretical expectation based on a literal extrapolation of Dirac's theory. This result suggested caution in generalizing from Dirac's theory. Even in 1955 at least one distinguished physicist had bet money against the existence of antinucleons. For many years, experimental physicists had looked for antiprotons in cosmic rays, with inconclusive results. Among others, Bruno Rossi and his collaborators, using a cloud chamber, and Edoardo Amaldi and collaborators, using photographic emulsions, had observed particles in cosmic rays that may have been antiprotons. Their observations were not, however, sufficient to establish the particle.

In planning the bevatron, Lawrence and the Rad Lab physicists had consciously chosen as a goal an energy of 6 GeV, slightly above the threshold for the formation of nucleon-antinucleon pairs from a proton colliding with a nucleon at rest. In 1955 the bevatron reached this design energy and thus afforded the opportunity of proving the existence of the antiproton unequivocally, and we wanted to settle the question once and for all.

Several Berkeley groups started the hunt. My group had for some time studied the problem and prepared for it. I decided to attack the problem in two ways. One was based on the determination of the charge and mass of the particle. The other concentrated on the observation of the phenomena attendant on the annihilation of a stopping antiproton. The stopping antiproton and a proton of the target should mutually annihilate each other, and the rest mass of the two particles should transform itself in one of many possible ways into other particles such as pions. These would leave tracks in a photographic emulsion and the annihilation would thus become evident.

For the first attack, Chamberlain, Wiegand, Ypsilantis, and I designed and built a mass spectrograph with several technically new features. For the second attack, Getson Goldhaber, who was then in my group, exposed photographic emulsions in a beam enriched in antiprotons by our apparatus. Many other people were involved in the enterprise, and we had agreements on how to publish the results and give appropriate credit to everyone. The proper working of the bevatron under Edward Lofgren was of paramount importance. We were in competition with physicists of other groups trying to detect antiprotons at the same time, but this did not prevent frequent mutual help.

We started the run on August 25, 1955, and after a few days of tuning up, we began observing antiproton signals. We based the identification on measurement of the velocity, momentum, and charge of a particle. The signals for velocity were oscilloscope traces recording the passage of a particle through a velocity-selecting Cherenkov detector, corroborated by a measurement of the same particle's time of flight between two detectors. The trajectory followed by the particles gave their momentum and the sign of their charge. Velocity and momentum determined the mass of the particles and this, combined with the sign of their charge, identified them as antiprotons. We also checked, among other things, that protons below the threshold energy did not produce our signals.

We detected about one antiproton for every few hundred thousand other particles crossing our apparatus, and the good signals arrived with a frequency of a few per hour. Naturally there was considerable enthusiasm in the laboratory, and many people came to see our progress. So as to be able to work undisturbed, we wrote up a bulletin of our results on a blackboard. In the meantime, we had to think about writing a paper and there were also delicate questions of the order of names and formulation of the text to consider. We decided to write a letter to the Physical Review and an article for Nature ,[6] to which I had written every time I had something important to say, or at least something I thought was important. We listed the authors in alphabetical order, as we had done in most of our many common papers before. Some original pieces of the apparatus, such as the Cerenkov velocity selector, were later described in greater detail by Chamberlain and Wiegand.[7]

I had no doubt that antiproton was the right name for the new particle. Lawrence preferred negative proton, but he did not insist. The mass spectrograph experiment concluded on October 1, 1955, having proved the existence of the antiproton, and soon thereafter the emulsion work confirmed it.[8]

At that time the physicist Oreste Piccioni wrote a scathing letter to Lawrence accusing us, and me in particular, of several misdeeds. Lawrence looked into Piccioni's accusations and dismissed them. Piccioni had made some good suggestions during the planning of the experiment, and these were duly and repeatedly acknowledged in publication. This was his pretext for starting a legal action against Chamberlain and me eighteen years later, in 1972, in which he maintained that we had stolen his ideas. The complaint went all the way up to the U.S. Supreme Court, but all the courts, from the Alameda superior court to the Supreme Court, refused to hear the case, because the statute of limitations had run its course.[9]

One day when I was complaining about the aggravation caused to me by Piccioni, a famous physicist who was an old colleague of his kept exclaiming, "Poor Oreste! Poor Oreste!" I resented this and demanded, "Why poor Oreste and not poor Emilio?" To which he promptly answered: "No; poor Oreste and not poor Emilio, because Oreste is crazy, and you are not!"

At the time of the antiproton experiment, Amaldi and his wife Ginestra were at our home in Lafayette as our guests. He and I established a collaboration for the study of photographic emulsions exposed at Berkeley, taking advantage of the numerous well-trained scanners available in Rome. When Amaldi returned to Italy, some Italian newspapers wrote inappropriate comments and tried to ascribe to him a part he had not played. This misreporting could have had unpleasant consequences, but Amaldi set things straight and we kept calm. The experiment was widely acclaimed and soon we, and Lawrence, started receiving numerous compliments on it. Lawrence politely answered those addressed to him with a form letter saying that he had passed the congratulations to Chamberlain, Segrè, Wiegand, and Ypsilantis, the people directly involved. Shortly afterward, another group in the lab, including Piccioni, observed the antineutron, obtaining it by charge exchange from the antiproton.[10]

Once we had discovered the antiproton, we obviously wanted to know the properties of our particle and build on our initial success. Some "battleship experiments," such as cross-section measurements, were possible, and we performed them, but our antiproton source was weak and it was soon surpassed by other accelerators that were coming on stream. With our means we could not do much more than what we had already achieved. However, in collaboration with Wilson Powell's group, which had a propane bubble chamber, we obtained some good pictures of antineutrons obtained from antiprotons by charge exchange,[11] and using photographic emulsions we started developing statistical information on the annihilation process. In the meantime, Alvarez's group had developed the hydrogen bubble chamber, and I proposed a collaboration, but he felt we did not have an adequate contribution to offer and demurred. Soon the Alvarez group, using their hydrogen bubble chamber, started obtaining capital results. Bogdan Maglic, a Yugoslavian postdoctoral fellow, pioneered in detecting the first resonance between annihilation pions, and this was the curtain raiser for a whole series of brilliant investigations.[12] By now (1986) there are accelerators forming beams of antiprotons and using proton-antiproton collisions in great storage rings. This is a measure of the pace of progress in particle physics.

Theoreticians had speculated on the rho and omega mesons, and members of my group tried to see them experimentally with a big new instrument, planned and developed chiefly by Ypsilantis and Wiegand, which we called the "fly eye" because it contained many scintillators that formed a sort of big compound eye. The technique was state of the art, and this work contributed, in a small way, to the discovery of the rho meson.[13]

In 1955 the discovery of the antiproton reopened the possibility of my winning a Nobel Prize. After the war I had started thinking that my work on the new chemical elements and on radiochemistry might bring me that distinction. I saw Seaborg's efforts at getting it on similar grounds, but I did not know how to stake my claim. I hoped that the Nobel Committee would somehow split the award. A poll among members of the Chicago section of the American Chemical Society in 1947 had chosen me as one of the ten best radiochemists in the United States.[14] Lawrence, too, as I found out many years later, considered me a good candidate.[15] "Contrari ai voti poi furo i successi" (Events turned out contrary to hopes; Ariosto, Orlando furioso 1.9.5); while I was at a cocktail party at Donald Kerst's house in Urbana in October 1951, I heard that the Nobel Prize for chemistry had been given to McMillan and Seaborg "for their discoveries in the chemistry of transuranium elements." I was deeply disappointed.

During the summer of 1954, I met Hevesy in Brazil. We were friends and I could speak freely to him. Thanks to his Swedish connections, he knew many of the secrets of the Nobel Committee, and he told me that I had not been specifically nominated in the year 1951, which had automatically eliminated me. He advised me to try to interest Fermi. I
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did not do so because I knew perfectly well that Fermi could not be influenced in matters such as competitions and awards.

However, a few years later, after Fermi's death, his widow, Laura, asked me to look at her husband's papers before she gave them to the Regenstein Library at the University of Chicago. In so doing, I found out, to my surprise, that both Fermi and James Franck had proposed me repeatedly for the Nobel Prize in chemistry. I saw also that Fermi had proposed, in physics, Maria Mayer, Hans Jensen, and Wolfgang Panofsky. His spontaneous proposal deeply moved me, for the same reasons that had prevented me from asking for his support. Nomination by him was, for me, almost as important as getting the prize. Much later I had the opportunity to tell Mayer, Jensen, and Panofsky that they had been nominated by Fermi, and all three had the same reaction. Of them, Mayer and Jensen had had the prize. Panofsky had not.

The discovery of the antiproton had some unpleasant consequences for the structure of my group and for relations between its members. Owen and Clyde, who were charter members of the group, developed most of the electronic detectors and counters of different kinds. Getson Goldhaber, the group's expert on photographic emulsions, was recruited by me in the early 1950s at Columbia University, where he had studied with Gilberto Bernardini.

After the discovery of the antiproton and connected publicity, the moods of Owen and of Clyde separately darkened. Owen wanted to be more independent than he already was, which was hardly possible. He wanted to have his own group, but our group was so small that I felt further splitting would seriously impair its efficiency. Owen was then invited to go to Harvard, where he spent a period as a Loeb Professor; on his return, he started a small separate group. Clyde, too, wanted to go it alone, and above all to work independently of me and of Owen. Perhaps he wanted to show his personal prowess, although his ability was widely recognized, above all by me and by his other colleagues in the group. It is possible that even Ypsilantis had similar wishes, but being younger, at the beginning of his career, and of a sunny disposition, he was less affected.
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In my opinion, the strength of our group came from the combination of different talents. Nobody could dominate by his obvious and disproportionate superiority, as had been the case with the various groups led by Fermi. As things were, I firmly believed that fragmentation or dissolution of our group would damage us all and impair our scientific output. No one else among us had Owen's critical mind, Clyde's technical ability, Tom's enthusiasm and optimism, and so on. Nor did I think that my contribution was as negligible as it perhaps then appeared to Owen and Clyde. One element of discomfort was the fact that both had been my students and co-workers for over fifteen years; the problems to some extent resembled those that arise between fathers and sons.

I thought that for me the best course was to give broad autonomy to the younger members of the team and try to aid their personal initiatives as much as possible. Some of these initiatives went well, some were less successful. Our group was too small to compete with the much larger groups then entering the field of particle physics, but to enlarge it greatly did not suit my modus operandi.[16]

A few years after we received the Nobel Prize and Owen seceded from the group, he changed his mind and, to my great joy, rejoined us. I expected that, being fifteen years younger than I was, he would in time succeed me as head of the group, with Ypsilantis as second in command. This happened for Owen, but unfortunately Tom left Berkeley before he was offered the opportunity.

Of the experiments we did after the discovery of the antiproton, I have already mentioned the one on the rho meson. Others, such as the pion beta-decay experiment,[17] were successful, but took much time, above all because the authors, in our tradition, properly insisted on measurements of superior quality. Much later Clyde Wiegand continued excellent experiments on mesic atoms on a small scale with a few students.[18]

A few months after the antiproton work, in the spring of 1956, I unexpectedly received a telegram from the secretary of the Soviet Academy of Sciences inviting me to an international science conference
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soon to be held at Moscow. A few hours later, a similar telegram reached Owen Chamberlain. Lawrence, whom I consulted, objected to our going, mainly for political reasons. I thought otherwise and decided to accept the invitation, but I had to maneuver a little to avoid a direct clash with Lawrence. Our invitation was perhaps the first to come from the Soviet Union, and it arrived at a time when scientists, especially those who had been at Los Alamos, were considered privy to "atomic secrets," and when very few Americans had visited the Soviet Union. After a few days, invitations also arrived for McMillan, Alvarez, Panofsky, and others, so that it became difficult for Lawrence to thwart so many people eager to go.

The trip to the Soviet Union lasted about six weeks, and besides Moscow and Leningrad, we also went to Armenia. It was some time after the famous Khrushchev speech revealing Stalin's crimes. The Russians did not know its text, but large excerpts of it had appeared in the Western press, and our hosts asked us about it. My impressions of Russia are too superficial to be of value. We were obviously favored guests—witness our advantages, such as tickets to superb ballet shows, our priority in visiting the Kremlin, and similar privileges. To everybody's surprise, including mine, I even succeeded in obtaining payment from the Bureau of Foreign Translations for the translation of the first volume of Experimental Nuclear Physics, which I had edited. When I asked for royalties or compensation, adding that I would appreciate payment in U.S. dollars, the Russian bureaucrats were nonplussed, and answered that they would ask their superiors, and that I should return in a couple of days. When I returned, the answer was that the superiors had to ask still higher authorities and that I should return in a couple of days. I doubted anything would come of it. However, after three days, when I returned to inquire, I was told that the request had been granted and that I would receive the money in New York. I could scarcely believe my ears.

On this trip I saw Bruno Pontecorvo again for the first time since his defection. He was so little Russified that at the conference the Russians present told him to speak English, because they had difficulties
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in understanding his Russian. Some of his colleagues treated him as a "Party zealot."

The person that impressed me most among the scientists I met was Igor Tamm, who subsequently shared the Nobel Prize for physics in 1958. I immediately liked this cultivated and refined gentleman's warm personality. He was also obviously a courageous person who, although he dearly loved his country, did not hesitate to help it by saying what he thought true and fair.[19] L. D. Landau seemed to me very arrogant; he reminded me of Oppenheimer, although of greater ability as a physicist. I also saw Peter Kapitza, whom I had known at Cambridge in 1934, as well as his son, whom I had then seen in a cradle, but who now looked like his father twenty-two years earlier. Among other able physicists, I met the Alikanian brothers, Pavel Cherenkov, J. A. Smorodinsky, D. D. Ivanenko, I. P. Nikotin, Nikolai Bogoliubov, and Vladimir Veksler for the first time.[20] The small fry were scared to mention even the most innocent subjects. When I asked a young chemist working on technetium what he was doing, he answered evasively and referred me to his superiors; when I pressed him to say what he had in a test tube he was holding, he said disconcertedly that he did not know! Furthermore, in the laboratories, I noted doors sealed with wax seals, as if there were great secrets behind them.

Later we flew to Armenia; during the flight we passed over the Turkish-Russian border, where one could see an abundance of military airfields. I asked for permission to take pictures, and the guide who accompanied us assented freely. I was surprised, but took the photos. Years later I came to think this may have been foolhardy on my part.

In Armenia we climbed to a high altitude observatory. A snowstorm trapped us inside the observatory, and the Armenians, feeling at home, started freely expressing thoughts that at sea level and among Russians would have been dangerous. I also saw ancient churches and monasteries, in one of which an old priest took me aside and bitterly complained to me in French about the negligence of the authorities, who did not provide the necessary funds for the preservation of the monuments of the past.
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I returned twice to Russia, the last time for the centenary of Mendeleyev's table of the elements in 1969. In 1957, some of the Russian scientists we met returned our visit by coming to Berkeley, and I invited them to our home. On the way there, as luck would have it, we had a blowout, the only time this had happened to me in thirty years. The Russians were amused by this failure of American technology and chuckled freely, but fortunately a colleague of mine, the physicist Herbert Steiner, was in the car. As a student, he had worked in a gas station and he showed the Soviet visitors the speed with which one changed a tire in the United States. The guests were impressed. Unfortunately, the Russians permitted by their authorities to visit us were few, always the same, and often not those we were most eager to see.

In 1957 Tsung-Dao Lee and Chen Ning Yang proposed the nonconservation of parity in weak interactions. Very crudely, the nonconservation of parity means the following: if one performs an arbitrary experiment—for instance, if one observes the disturbance of a magnetic needle by an electric current—and one looks at the experiment or at its image in a perfect mirror, and there is no way of telling which is which, parity is conserved; on the other hand, if it is possible to tell apart object and image, parity is not conserved. In all experiments performed up to 1957, parity seemed to be conserved.

In the same year, the tau and theta meson decays (now they are both called K mesons) showed a peculiarity. The particles have the same lifetime and the same mass but decay in final states of different parity. Lee and Yang suggested that they were one particle with two different modes of decay. There are many examples of dual decay, but the difficulty in this specific case was that the decay to two states of different parity necessitates a parity change in the decay. This had never been seen in electromagnetic or strong decays but had not been ruled out experimentally in decays by weak interaction.

Lee and Yang pointed this out. Chien-Shiung Wu and her colleagues at the National Bureau of Standards showed, in a case of beta decay, that the Lee-Yang hypothesis was correct: parity was not conserved. Within a few days this surprising result was extended to muon decay
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by Richard Garwin, Leon Lederman, and Gabriel Weinrich at Columbia University, and it turned out that Valentin Telegdi at the University of Chicago had previously had indications of the same phenomenon. The sensational discovery removed an old and firmly established prejudice and opened new horizons to the theory of weak interactions. Everybody rushed to work on the subject, with an eagerness reminding me of that following the discovery of fission in 1939, or of hightemperature superconductivity in recent years.[21] Fermi may have had some thoughts on the subject; he had occasionally cryptically remarked to me that nobody had ever inverted space (like a glove), transforming a left hand into a right one, but he left no written document of what he had in mind. I was deeply interested in the discovery of parity nonconservation and tried to read and understand the new papers on the subject that flooded the literature. Less agreeably, from a narrow and selfish point of view, I realized at once that the new discovery postponed the possibility of my winning the Nobel Prize; I was sure Lee and Yang would have priority. Tough luck, but there was nothing I could do.

In October came the announcement of the awarding of the Nobel Prize in physics to Lee and Yang. Nobody was surprised; it was an almost perfect opportunity to follow literally the wishes of Alfred Nobel as expressed in his will. I was curious whether the sages of Stockholm would also include C. S. Wu, but they did not. Many years later I was pleased when she won the important Wolf Prize.

In July 1958 I went to Geneva for an international scientific conference at CERN. At the same time there was a disarnt conference between United States and the USSR. Lawrence and Panofsky were among the American experts; Igor Tamm, whom I had come to know in Moscow, among the Russians. I met Tamm on the street and, knowing that we both liked hiking, I suggested we hike Mount Saleve, in France. He answered that he could not because he did not have his passport. Foolishly thinking that he had simply left it at his hotel, I said, "Let us go and fetch it." Tamm then explained to me that he did not have his passport because on his arrival the Soviet consul had impounded it. I blushed at my lack of tact in asking, and I am still amazed at a country that would take away the passport of one of its important
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delegates at an international conference, and that of a man of Tamm's stature.

I saw Lawrence only in passing. While he was in Geneva he had a serious recurrence of a colitis that had long afflicted him. He returned to Berkeley and went to Stanford University Hospital. I was worried by his condition and looked in a medical manual for information about his illness. I found that it is an insidious disease with acute periods alternating with remissions. The patient used to this cycle may delay an operation too long, until it becomes dangerous. I had read this when I heard the sad announcement of Lawrence's death on August 27, 1958, in circumstances similar to those described in the manual.

Lawrence was an intense, impulsive, optimistic, and very active individual, more a doer than a thinker, and a born leader of men. He was full of contradictions, which made him unpredictable. His personality was fundamentally generous and magnanimous, but he could occasionally be petty. His optimism and enthusiasm, basic ingredients to his success, led him sometimes beyond where he should have gone as a scientist. He enjoyed life to the full and drew great satisfaction from his scientific successes and those of his associates, but he also pursued childish ambitions of consorting with rich and powerful people. His political activity, the dark side of his life, is scarcely known to me. In his youth he started as a liberal in the midwestern tradition of Robert La Follette, as one might expect given his family origins; but he ended as a reactionary. I personally am grateful to him for the help and the opportunities he gave me.

At the beginning of 1957, Seaborg told me that he thought Lawrence's nomination would he indispensable for the awarding of the Nobel Prize to anyone working in the Rad Lab. I said that I would not speak to Lawrence on this subject, but that if he, Seaborg, would do it, I would be grateful. A few weeks later, Lawrence's secretary, without a word, showed me, on Lawrence's orders, a letter from Stockholm acknowledging receipt of my nomination by Lawrence. No word on the subject passed between us.

Also in 1958, I was given the Hofmann medal of the German Chemical Society. At first I was uncertain whether or not to accept it, given
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recent German history, but I decided, I believe correctly, to do so. It was a high distinction, and I liked being recognized by chemists. I went to Wiesbaden at the end of September 1958 to receive the medal at the meeting of the Gesellschaft Deutscher Naturforscher und Ärzte. It is a big affair, with scientists of all specialties and also philosophers. I spoke, in German, on a subject I was interested in—that is, on systems similar to atoms, but constituted of particles different from electrons and ordinary nuclei, something on the borderline between spectroscopy and chemistry.[22] At Wiesbaden I found Otto Hahn, with whom I renewed an old friendship. We sat next to each other in the front row at a conference addressed by the philosopher Karl Jaspers, who had attracted a huge crowd. The speaker was rather theatrical and, I thought, tried to look like the old Goethe, but I did not have the impression he said much. Hahn had fallen asleep, but at a certain point Jaspers started attacking science and scientists. Exactly at that moment, Hahn woke up, turned to me, and said: "By scientists, he means you and me."

The death of Lawrence necessitated the appointment of a new director for the Radiation Laboratory. The obvious choice was Edwin McMillan. He belonged to Lawrence's old guard, he was an eminent physicist who had greatly contributed to the laboratory's success, he was a distinguished accelerator's expert, and he was well liked by most of the personnel. He lacked Lawrence's charisma, but that could hardly be duplicated.

Under McMillan, the laboratory changed its name, becoming the Lawrence Berkeley Laboratory (LBL), while the laboratory in Livermore became the Livermore Lawrence Laboratory (LLL). The administration became less capricious than it had been under the creator of the lab, but also less enthusiastic and more bureaucratic. McMillan's assignment was tough. The unavoidable comparisons with his predecessor and the implacable personal hostility of Alvarez, who antagonized him constantly, added to the difficulties.

I spent a good part of 1958 in Rome as a Guggenheim Fellow. In applying for the fellowship, I gave Franco Rasetti as one of my references; a couple of weeks later, I received a letter from the Foundation asking me for a letter of recommendation for Rasetti, who had also
― 268 ―

applied and had given my name as a reference. The accident was comic, but also embarrassing, and I wrote to the Foundation explaining our predicament and innocence of collusion in the matter. We both received fellowships, and later I served for many years as a consultant to the Foundation.

I devoted the time of my fellowship to the preparation of the two volumes of Fermi's collected papers. Since he had died at such an unfortunately early age, there still were many witnesses who were able to write valid historical introductions to individual papers. I took responsibility for the organization of this work. I felt an obligation, having been close to Fermi in Italy as well as in America, and I remembered, without wanting to make ridiculous comparisons, that Maxwell had edited Cavendish's collected papers and Marie Curie those of her husband. The job required considerable time and effort even with the help of other members of the editorial committee; Amaldi, Anderson, Persico, Rasetti, and Wattenberg carried a substantial part of the load, as did several outsiders. The biographical introduction I wrote for Fermi's collected papers served me as the basis for his biography, which I published ten years later.[23]

On January 19, 1959, the University of Palermo gave me an honorary degree, which I highly appreciated. On the occasion I visited Palermo for the first time since the war. The city had greatly deteriorated and the elegant surroundings of our house at the beginning of Viale della Libertà had badly decayed. I saw again the Istituto fisico in Via Archirafi and several of my old Sicilian friends. After our stay in Palermo, we toured Sicily once more and visited Syracuse, which we did not yet know.

A little later, in February, I had to go to Scandinavia. I was invited to visit Bohr's Institute in Copenhagen, and to Stockholm and Oslo to lecture for Nordira, an association of Scandinavian universities. I was thus able to see Bohr again, as well as the two Siegbahns, father and son,[24] Oskar Klein and other colleagues. I had a friendly reception everywhere, and I suspected that I had not been invited solely to show me the wintery attractions of Scandinavia.

On my way back I stopped at Hamburg, where I lectured on February
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16, 1959, on the invitation of W. Jentschke, a physicist I had befriended in Urbana in 1952 and who later became director of CERN. I spoke at the old Stern Institute, where I had worked about thirty years earlier. In the audience were some professors who had been Stern's assistants; I knew they had become zealous Nazis under Hitler and avoided them.

By chance I had read a newspaper advertisement placed by a detective who specialized in locating people. Out of curiosity, I wrote to him a few days before my arrival in Hamburg, asking him to find my old girlfriend, "I." All I had to go by were her maiden name and her address in the 1930s, but for a very modest fee the detective supplied me with her married name, address, and telephone number, as well as a description of her husband, his profession, and their financial and family situation. Immediately after the detective left my Hamburg hotel, I called her number. She answered herself, and I did not have the impression she was excessively surprised. We made an appointment to see each other the next day, and when we met we spoke about some of the past and little of the present. She did not believe in the reality of the Nazi crimes, which, in an intelligent person, astounded me. The denial can be only explained by the terrible difficulty of facing the facts. She had two daughters, whom I did not see. A few years later they sent me a printed announcement of the death of their mother.

On my return to Italy, in March 1959, I attended an award ceremony for old employees of SCT, my father's paper mill, and I was asked to confer the medals. I deeply appreciated being chosen for this as the representative of the family.

When I returned to Berkeley, the date for the announcement of the Nobel prizes was approaching and some Swedish journalists called me from New York asking for biographical details. I was high in the balloting of the awarding committee, they said. That year, contrary to all precedents, the Nobel committee had leaked information to the press about a week before the final vote. Thus they kept me, and other hopefuls who had been named, on tenterhooks for a week. Finally, on October 26, I heard the announcement on the radio, and shortly thereafter I received an official telegram. Needless to say, before the announcement I did not know if and how a prize given for the antiproton
― 270 ―

would be divided between Chamberlain, myself, Wiegand, and Ypsilantis, since the paper reporting the discovery had been signed by all four of us in alphabetical order. The Swedish Academy of Sciences decided to award the prize to Chamberlain and myself. Chamberlain was at Harvard at the time, and he telephoned me to plan the speeches we would give at Stockholm. I left the choice to him, and he asked to speak about the technique followed in revealing the antiproton, leaving to me the consequences of the discovery. I willingly agreed.

The trip to Stockholm was more or less the same as that of all other laureates, very interesting and satisfactory. The three children accompanied us. Amelia had caught poison oak a few days earlier, and her face was badly swollen. I told her that if she did not scratch herself, she would most likely recover before the time of the ceremonies. So it was. I always admired the willpower of the little lady.

Following tradition, I gave a short speech of thanks on behalf of all the laureates at the royal banquet that celebrated the awarding of the prizes.[25] As I have observed elsewhere, I had borrowed my friend Ancona's tailcoat for the occasion. I had also obtained a white waistcoat that had been used by several Berkeley Nobel Prize winners from McMillan, who asked me to sign it. One of its wearers even told the king of Sweden the story, saying: "Sir, please look carefully at this waistcoat. You have seen it repeatedly." At the royal dinner I had a most interesting conversation with the king, who knew Italy very well indeed.

Later in the evening, at the students' dance, I had to give a second speech. Here is what I said:

Students, Ladies and Gentlemen:

Although we have a poet in our midst [Salvatore Quasimodo], who would be far more eloquent than I can be, I have been chosen to answer your gracious and heartfelt greeting, and I will do my best.

We Nobel laureates, although we work in widely diverse fields, share at least one thing in common: we spend a good part of our life teaching and working with students and young people like you, the new generation on which the future depends. Usually we are before you to discuss our special fields of interest. Tonight we may well speak to you in broader terms.

― 271 ―

It has almost become a custom to tell animal fables on this occasion. Two years ago perhaps you heard a wise Oriental one from my friends Lee and Yang. I do not know the origin of the one I am going to tell you. Perhaps it is Swedish, and so you may already have heard it. The person who taught it to me was an old Quaker lady from Pennsylvania [Lorenzo Emo's grandmother].

Two frogs were leaping and frolicking in a meadow when they spied a strange object. Being curious, they decided to investigate it, and the way frogs investigate things is by jumping into them.

In this particular object they found themselves very much at home, because it was a pail full of milk. For a time they had a splendid time swimming about. Then they felt tired and began to seek solid ground, because, as you know, frogs cannot live indefinitely in a liquid.

Much to their consternation they found that there was no island in this pond of milk. Panic-stricken, they tried to jump out of the pail, but the walls were too high and too slick and they fell back. Again they jumped and fell back, and then again and again. The situation became more and more desperate.

At last one of the frogs gave up. The walls were far too high, the surfaces far too smooth to climb up, he reasoned. Clearly there was no hope. He fell back and drowned.

The other frog, perhaps a little less intelligent, but far more stubborn and persistent, continued jumping. Over and over he leaped up and fell back. He was at the point of complete exhaustion and nearly resigned to joining his fellow.

And then he felt something firm and hard under his legs. A little island of butter was forming. With a few more jumps, he churned an island that was big enough so that he could rest and then jump out of the pail, and so he was saved.

I leave the moral to you, but it must be a powerful one because I still remember the old Quaker lady of Pennsylvania telling me the story in 1940, during the darkest days of the war.

I always liked the story, which I fancied reminiscent of my own experience. On this occasion my audience bestowed on me the "Order of the always smiling and jumping little frog."

I had time to see Oskar Klein and Lise Meitner (by then rather aged) in Stockholm. I also went to Uppsala to Kai Siegbahn's institute to give a lecture, but I had to hurry to Rome for SCT business.

I have always regretted that neither my parents, my uncle Claudio,
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Corbino, nor Fermi were able to see me getting the prize. My parents' satisfaction would very likely have exceeded my own. I can hardly imagine that of Uncle Claudio, who gave me a pair of gold cufflinks simply because I had received a superior grade in a mechanics exam. By now I had all the public recognition I could hope for; self-esteem is something else. I believe I never got a swollen head. That there is no honor that can affect my accomplishments is a hard fact I have always kept in mind.

The reason for the prestige of the Nobel Prize for physics is that, all told, it has been given well. This does not mean that there have not been some lucky mediocrities who have received it and some eminent deserving scientists who have been passed over. For the former, it was a stroke of luck; for the latter, apart from worldly disappointment, it is unimportant. Persons such as Einstein, Planck, Rutherford, and Bohr have given the award its prestige. If one or more of them had not received it, the loss would have been entirely to the prestige of the prize, not to them. Considering all the laureates, one can divide them into three groups: one group has given prestige to the prize, one has been exalted by it, and one has more or less broken even.

In the nominations for Nobel Prizes or other important awards, the decision is easy when there are truly extraordinary candidates, but even there, the diversity of the fields in physics may make some choices difficult, and I have found that there have been some glaring omissions, such as that of G. E. Uhlenbeck and S. A. Goudsmit, who discovered the electron spin.

The monetary value of the prize was initially very substantial, corresponding to about fifteen times the yearly salary of a distinguished professor. In 1959 it amounted to $21,184 for each of us, and my net annual salary at the time was about $13,000. Of course, the prize also provides many less tangible advantages: invitations, prestige among one's colleagues, the chance to be on various committees, numerous opportunities to serve as an ornamental plant, and even some minor monetary advantages. At Berkeley, in recent years, one is even given a private parking place on campus!

There are also drawbacks: one automatically becomes an oracle on
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every topic, and one is subject to distractions from work and difficulties with jealous colleagues or collaborators. Above all, sensible persons, which Nobel Prize winners usually are, know that what counts is their work.

"Emilio, you could take all your work and exchange it for one paper of Dirac's and you would gain substantially in the trade," Fermi once said to me. I knew this to be true, of course, but I answered: "I agree, but you could likewise trade yours for one of Einstein's and come out ahead." After a short pause, Fermi assented. I know of scientists who cannot resign themselves to being inferior to contemporaries, with dire consequences for their personalities and happiness.

Finally, being a celebrity may give rise to amusing episodes. For example, at the time of the discovery of the antiproton, I happened to read an article in the New Yorker in which Salvador Dali said he had abandoned Freud, and that his "father" was now Heisenberg and his credo the uncertainty principle. In particular, he had painted or was about to paint an antiprotonic madonna. I then wrote to him and sent him some beautiful pictures of antiproton stars in photographic emulsions, saying that I was curious as to how he visualized antiprotons. He did not answer. Shortly after receiving the Nobel Prize, I was in New York at Robert Serber's house at a cocktail party with several physicist friends. During the party George Placzek and I modeled a mink cape I had bought for Elfriede, with everybody laughing merrily. In this joking mood I said I would look up Dali and see him before leaving New York. Everybody laughed at the idea, but the next day I found Dali's address and telephoned him at the hotel where he lived, explaining who I was and reminding him of the photos I had sent to him.

He was most friendly and invited me to come to see him at 8:30 that evening. Given the time, I thought this was after dinner, and I ate before going to the appointment. I called him from the lobby of his hotel, and he came down very shortly. I had started having doubts about what would happen next and thought that perhaps he might want to amaze me in some way or other. I therefore hid behind a column from where I would be able to see him immediately, but he would have to look for me for a few seconds at least. I counted on this interval to
― 274 ―

prepare myself in case he had something up his sleeve. Indeed, he arrived with his moustache stiffly pointing upward, a thin cane, and strange attire that seemed a caricature. I looked at him from my hiding place for a fraction of a minute and then greeted him in the most natural way, without showing the slightest surprise. "What language shall we speak?" he asked. "Any," I replied, as if I knew them all. By now we were competing in one-upmanship. We settled on French, mixed with much English. It turned out that Dali, who was accompanied by his attractive and interesting wife Gala (whose history I did not know), intended to invite me to dinner. I did not say I had already eaten but ate once more, lightly. After a while, it must have been apparent that the competition in one-upmanship was a draw, and the game subsided.

Dali explained to me that he was truly interested in modern physics and that he had read several articles in the Scientific American , which was obvious from the way he spoke of quanta, the uncertainty principle, antimatter, and so on. All these ideas had, however, suffered a sea change in his mind that I could not grasp, but that was obviously sincere and interesting. His paintings of soft watches bending and dripping as if they were cheese had hidden physical and psychic meaning for him. He explained to me that the madonna he had painted was "antiprotonic" because only the annihilation of matter could give sufficient force to propel a woman to heaven. As he spoke I became convinced that he had a way of seeing the world different from that of a scientist, certainly more subjective, but also valid in its own terms. We then passed to artistic technique. He said he painted many hours a day, slowly and with extreme care. "If you look at my paintings with a magnifying glass, you will discover many things, because I often paint using a magnifying glass, and details are almost invisible without it." I hoped that he might give me a drawing in exchange for what I had sent him, but instead he sent me a book of reproductions of his work with a dedication. I regretted not having read the book before our meeting; it also contained the whole history of his wife Gala. She had listened to our lively conversation, speaking only rarely, mostly helping us when we searched for words, but I saw she was his constant model and obviously in many ways an inspiration.
― 275 ―

In March 1960 I gave the Faculty Research Lecture at Berkeley, for which I had been selected before receiving the Nobel Prize. This lecture is a high local honor conferred on members of the Berkeley faculty by their colleagues.[26] Following the lecture, I was on the selection committee for ten years or so, and there, contrary to what had happened on other Berkeley committees, I saw a certain spirit of partisanship based on disciplines. Ultimately, on Alvarez's suggestion, the Berkeley Academic Senate resolved to appoint two faculty research lecturers yearly, one for the humanities and one for science.

The year 1960 was saddened by several tragedies. On April 23, Cornelius Bakker perished in an airplane accident. We had been friends since 1930, when we collaborated in Zeeman's laboratory. After the war Bakker had visited me in Berkeley, and we had even conducted a small investigation together. He had later become the director general of CERN, and I had visited him at Geneva. Amaldi and Bernardini thought of nominating me as his successor at CERN. I was somewhat surprised, but I agreed to stand for the appointment. The CERN directorship would have given me a new activity that at my age and at that phase of my career appealed to me. However, the nomination was received coolly and a campaign for another person was immediately started; I then withdrew my candidature.

A few months later an unexpected blow struck us. Our dear friend Francis Jenkins, who had helped us so much in difficult times, and to whom we were very close, fell incurably ill and died. During the summer, Elfriede and the children had gone on a tour of New Mexico, revisiting Los Alamos. I did not leave Berkeley because I knew of Jenkins's condition and wanted to be on hand in case I could in any way be of help. I wrote a deeply felt obituary and spoke at his memorial service. In 1967 his wife, Henriette, also died, to our deep sorrow.

In the autumn of 1960, the Rockefeller Foundation invited me to go to Nigeria for that country's independence proclamation, scheduled for October 1. It was a unique opportunity, and Elfriede and I stayed there for about three weeks as guests of Ibadan University. It was my first trip to Africa, and I knew very little about it. I bought light clothes suited to the climate and a pith helmet of the kind once usual in Africa,
― 276 ―

but I was told on arrival to suppress this headgear at once, as it was considered a symbol of colonialism. After our first official dinner, with everybody formally dressed in black tie, I was surprised when the ladies retired and the men went to urinate on the host's lawn.

One evening while touring the country, we visited the Oba of Benin, who lived in a big mud palace, together with his court, which included many wives and about fifty children. The anthropologist M. J. Herskovits, who was also in the party, asked the Oba many questions on justice and law in Benin, and how he reconciled them with British law and the religious commandments of the several prevailing faiths. The Oba had been educated in England, spoke the language well, wrote with a modern fountain pen, and had inscribed photographs of several members of the English Royal Family. He complained about his children, who all wanted to go to Eton, an expense he could not afford. As he spoke, some of these children showed up stark naked in the reception hall, only to be promptly dismissed.

After a while the Oba politely hinted that he had enough of the anthropologist's questions and turned to me, saying that he knew I was a physics professor and hoped I could help him to clear up the confusion he felt when they told him the earth was spherical, while old traditions said it was fiat and so it appeared to him. Furthermore, he could not understand how the sun disappeared every day from a certain part of the horizon and reappeared on the opposite side the next morning. I tried as best as I could to explain these mysteries to him, and he then passed to the moon. How far was it? Would the Americans or the Russians arrive there first? On the moon's distance I gave him some information, but I refused to predict who would arrive there first. On my return to Berkeley I bought an illustrated astronomy book for young people for the Oba. I did not want to offend him, however, so I sent it to him with a letter to the effect that I thought it might interest some of the children I had seen at his court.

At the proclamation of independence, the man slated to become the first prime minister of independent Nigeria, Sir Abubakar Tafawa Balewa, made a speech that impressed me greatly for his realism, and
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equilibrium. He pointed out grave problems facing the new nation and some of the necessary remedies. Within a few months he was murdered.

In my academic career, I long avoided administrative work. This was easy to do, but I nevertheless ended up shouldering many responsibilities in this field too, especially in later years. As a rule I have accepted assignments if asked to by the university, the government, or some other public institution, but I never strove to join boards, directorates, committees, and so on. Since there are always many people eager to serve in such offices, those who do not show a keen interest in the jobs do not get them.

However, at the University of California at Berkeley I have ended by serving on most

Machine Vision

Mind

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یک ذهن همواره در حرکت (۴)

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یک ذهن همواره در حرکت (۳)

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یک ذهن همواره در حرکت (۲)

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یک ذهن همواره در حرکت (۱)

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یک ذهن همواره در حرکت (۷)

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یک ذهن همواره در حرکت (۵) [لوس آلاموس، برکلی، جنگ، بمب، فرمی، ایتالیا، اوپنهایمر]

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یک ذهن همواره در حرکت (۴) [لارنس، برکلی، سیبورگ، فیزیک، فرمی]

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یک ذهن همواره در حرکت (۳) [پالرمو، الفریده، فیزیک، رم، پرتوزا، فرمی، ایتالیایی، برکلی]

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یک ذهن همواره در حرکت (۲) [فرمی، فیزیک، رم، آمالدی، نوترون، هسته ای، زیمان، الفریده]

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یک ذهن همواره در حرکت (۱) [فیزیک، فرمی، تیولی، رم، ایتالیایی، رازتی، جنگ، ریاضیات]

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یک ذهن همواره در حرکت (۷) [برکلی، فرمی، فیزیک، لارنس، ایتالیا، نوبل، پادپروتون]

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ماشین ژن: مسابقه برای رمزگشایی از اسرار ریبوزوم (۲) [بلور، ریبوزوم، RNA، پروتئین، DNA، بلورنگاری]

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ماشین ژن: مسابقه برای رمزگشایی از اسرار ریبوزوم (۱) [ریبوزوم، پروتئین، بلور، اتم، مولکول، ویتمان]

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ماشین ژن: مسابقه برای رمزگشایی از اسرار ریبوزوم (۴) [ریبوزوم، RNA، بلور، 30S،‏ tRNA،‏ mRNA]

مشخصات

ماشین ژن: مسابقه برای رمزگشایی از اسرار ریبوزوم (۳) [بلور، 30S، ریبوزوم، RNA، پروتئین]

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ماشین ژن: مسابقه برای رمزگشایی از اسرار ریبوزوم (۵) [ریبوزوم، نوبل، RNA]

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لوئیس هارولد گری: یکی از بنیانگذاران رادیوبیولوژی (۳) [پرتو، تابش، سرطان، نوترون]

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ابررسانایی: اکتشاف ها و کاشف ها (۱) [لانداو، ابررسانایی، مغناطیس]

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نگرانی های ثروتمندان، نیازهای فقرا (۱) بهداشت، عمومی، شیوع، ویروس، بیماری

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لوئیس هارولد گری: یکی از بنیانگذاران رادیوبیولوژی (۳) پرتو، تابش، سرطان، نوترون

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ماشین ژن: مسابقه برای رمزگشایی از اسرار ریبوزوم (۵) ریبوزوم، نوبل، RNA

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ماشین ژن: مسابقه برای رمزگشایی از اسرار ریبوزوم (۴) ریبوزوم، RNA، بلور، 30S،‏ tRNA،‏ mRNA

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ماشین ژن: مسابقه برای رمزگشایی از اسرار ریبوزوم (۳) بلور، 30S، ریبوزوم، RNA، پروتئین

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ماشین ژن: مسابقه برای رمزگشایی از اسرار ریبوزوم (۲) بلور، ریبوزوم، RNA، پروتئین، DNA، بلورنگاری

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ماشین ژن: مسابقه برای رمزگشایی از اسرار ریبوزوم (۱) ریبوزوم، پروتئین، بلور، اتم، مولکول، ویتمان

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یک ذهن همواره در حرکت (۷) برکلی، فرمی، فیزیک، لارنس، ایتالیا، نوبل، پادپروتون

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یک ذهن همواره در حرکت (۵) لوس آلاموس، برکلی، جنگ، بمب، فرمی، ایتالیا، اوپنهایمر

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یک ذهن همواره در حرکت (۴) لارنس، برکلی، سیبورگ، فیزیک، فرمی

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یک ذهن همواره در حرکت (۳) پالرمو، الفریده، فیزیک، رم، پرتوزا، فرمی، ایتالیایی، برکلی

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یک ذهن همواره در حرکت (۲) فرمی، فیزیک، رم، آمالدی، نوترون، هسته ای، زیمان، الفریده

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یک ذهن همواره در حرکت (۱) فیزیک، فرمی، تیولی، رم، ایتالیایی، رازتی، جنگ، ریاضیات

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