Emilio Segrè

segre1959 Nobel Prize for Physics

• Presentation of Award
• Acceptance Speeches
• Biography Submitted by Dr. Segrè to the Nobel Committee
• Biography Submitted by Dr. Chamberlain to the Nobel Committee

• Presentation of Award: 1959 Nobel Prize for Physics

Press conference Nobel Prize announcement on a Lab blackboard.
Professor E. Hulthén, chairman of the Nobel Committee for Physics:
Your Majesties, Your Royal Highnesses, Ladies and Gentlemen,
The notion of matter as something built up of very tiny and indivisible atoms is a heritage from classical times. Since, however, experimental research in our days has shown that the atoms in their turn are complicated structures, the notion of indivisibility has been transferred to the so-called elementary particles of which the atom is composed, in the hope of therewith having reached the ultimate limit for the division of matter.

However, the different kinds of elementary particles showed an alarming tendency to increase in number–something which is at variance with the attractive idea that matter is built up of one or at most two kinds of particles.

Among the most successful and noteworthy attempts to interpret the situation is Dirac’s theory of particles and anti-particles, which may be designated, almost, as each other’s mirror-images. Both kinds of particles are conceived as arising through the formation of pairs and as reciprocally annihilating each other. The world in which we find ourselves belongs, by chance, to the one kind of particles, among which sporadically occurring anti-particles are very quickly destroyed. On account of the mirror symmetry it would be very difficult to decide whether a remote star or galaxy belonged to the one or the other kind of matter.

Emilio Segr&egrave in the early 1930s.
There were probably very few physicists who at first ascribed to this side of Dirac’s otherwise very valuable theory any real import until, quite suddenly and unexpectedly, the first anti-particle, the positive electron, was discovered by Anderson in cosmic radiation in the year 1931. Continued investigations showed that the new particle behaved in all respects according to Dirac’s theory: that it was manifested, namely, in connection with some energetic process, always together with an ordinary electron, and that it disappeared in the same way and with equal suddenness. Today nothing is better known and clearly elucidated than this process of pair formation and annihilation.

Dr. Emilio Segr&egrave, April 28, 1954.
Nonetheless it now seemed desirable to test the validity of this remarkable theory upon the anti-particle to the proton, the nucleus of the hydrogen atom–a process which required, however, about 2,000 times as great an amount of energy. Such quantas of energy do, certainly, occur in cosmic radiation, but in such a random way that it was finally realized that the only systematic way of investigating the process was through the controlled production of the anti-proton by means of an accelerator with a sufficiently high capacity.

Left to right are Dr. Emilio Segr&egrave, Dr. Clyde Wiegand, Dr. Edward Lofgren, Dr. Owen Chamberlain and Tom Ypsilantis, then a graduate student. The photograph was taken at Lawrence Berkeley Laboratory in October, 1955 at the time of the discovery of the antiproton.
It has been said of the bevatron, the great proton accelerator at Berkeley University in California, that it was constructed chiefly with a view to the production of anti-protons. This is perhaps an exaggeration, but in so far correct as its peak achievement, 6 milliard electron volts, was set with a view to the energy required for the pair-formation of protons–anti-protons. That it was constructed in Berkeley was due to the tradition established there ever since Lawrence built the first cyclotron and McMillan developed the principle for the synchronization of relativistic particles.

But even if anti-proton research was thus first made possible through this technologically very impressive machine, the actual discovery and investigation of the anti-proton was chiefly the merit of Chamberlain and Segr&egrave. With similar methods an anti-particle to the neutron has subsequently been discovered, a discovery whose importance lies in the fact that the concept of the anti-particle was thereby extended to include also the neutral elementary particles.

© the Nobel Foundation 1960

• Second Presentation Speech

Dr. Emilio Segr&egrave and Dr. Owen Chamberlain at the reception for Yuan T Lee, Nobel Prize recipient, 1986.
Your discovery of the anti-proton was made possible through the excellent resources at the Radiation Laboratory in Berkeley. It is, however, your ingenious methods for the detection and analysis of the new particle that the Royal Swedish Academy of Science wishes to recognize on this occasion.

I need surely not remind you, Professor Segrè, of the occasion, twenty-one years ago, when your compatriot Enrico Fermi received his Nobel prize in this self-same place. You and he were intimate friends and you had been collaborating with great success. Both of you belonged to that group of distinguished Italian scientists that was westward bound in those days.

Also you, Professor Chamberlain, must surely have an intimate and abiding recollection of your years together with Fermi in Chicago.

Gentlemen, I now ask you to receive your prize from the hands of His Majesty the King.

© the Nobel Foundation 1960

• Acceptance Speeches

M. Chamberlain
Owen Chamberlain checking the polarized proton target apparatus. He and Emilio Segr&egrave shared the Nobel Prize in physics in 1959 for their discovery of the antiproton.
Your Majesties, Your Royal Highnesses, Your Excellencies, Ladies and Gentlemen:
I am deeply moved by the great honor the Royal Swedish Academy of Science has bestowed upon me. I doubt that any man could feel himself worthy of this great distinction. Certainly I am filled with humility, for the list of the Nobel laureates includes many men of truly outstanding genius.

The development of physics, like the development of any science, is a continuous one. Each new idea is dependent upon the ideas of the past. The whole structure of science gradually grows, but only as it is built upon a firm foundation of past research. Each generation of scientists stands upon the shoulders of those who have gone before.

Dr. Owen Chamberlain
In a different way, each generation of scientists depends upon the previous generation for instruction and training. I was 21 years old when I came as a graduate student to the University of California in Berkeley. Within a short time I found myself working under Professor Emilio Segrè. Whenever there was a pause in the routine parts of our work, his agile mind produced intriguing questions and scientific puzzles to tease my intellect. A few years later, I worked under the late Professor Enrico Fermi, who was, I believe, the most intelligent man I have ever met. For a considerable period he devoted several hours per week to helping me with my research toward the doctor’s degree. When I faltered, he found a method of circumventing the difficulty. Professor Segrè has taught me the value of asking the right question, for by asking the right question one may find a key to new knowledge. From Professor Fermi I have learned that even the simplest methods may give answers to difficult questions.

Each generation of scientists also depends upon its own environment. Our researches are supported by the society in which we live. I have had the privilege of using the marvelously equipped Lawrence Radiation Laboratory in which so much of my work has been carried out.

The most that any scientist can ask is that he help to lay a few stones of a partially-built edifice that we call scientific knowledge. To him this edifice is a beautiful structure, although it will never be finished.

The late Alfred Nobel, through the medium of the Nobel prizes, has done much to dramatize this search for knowledge. In so doing, I am sure he has quickened the pace of scientific history.

In conclusion, I wish to express thanks, for myself and for my family, to the Nobel Foundation and to all of you here for a warm and very hospitable reception.

© the Nobel Foundation 1960

M. Segrè — First Address
Your Majesties, Royal Highnesses, Ladies and Gentlemen.

My eloquence is totally inadequate to add anything to the thanks so well expressed by the laureates who preceded me on this rostrum. I am sure that apart from our ability to express them, our feelings are similar and very deep indeed.

Dr. Emilio Segr&egrave with 25 volumes of ….
Alfred Nobel, as an idealist and as a man living in the second half of the 19th century, had high hopes for the future of mankind through science.

To use his own words:

The conquests of scientific research and its constantly enlarged fields of activity arouse a hope in us that microbes–both those of the soul and body–will gradually be eradicated and that the only war to be waged in the future by humanity will be the war against these microbes.

Sixty years after his death, after two world wars and other terrible experiences that have affected a large part of mankind, we might find his hopes too optimistic, based as they possibly were on the extraordinary period of peace and progress during the last part of the 19th century. Thus we find that in some respects his hopes for science have even been surpassed by the events. Indeed, the microbes of the body, in the literal sense, have suffered some defeats from which they will not easily recover. Also in other fields the progress of science during the last fifty years has been astonishing. Things which were unknown in my student days such as the neutron, have become of decisive importance to all mankind. At my age–and I’m only 54–I find that I have known and met persons which my students consider no less historic and almost as remote as Columbus.

But what about the microbes of the soul?

Here, after the lessons of the first half century, I think we are less optimistic than at the time of Nobel. It seems that the influence of science on human affairs has been different from what was postulated in Nobel’s time. Instead of being an unmixed blessing, it has brought out primarily a great increase in human technological possibilities, but whether they would be used for good or evil was left to Man to decide. The use of the tools was not prescribed a priori.

However, it is here that men of science have given us an interesting and profitable lesson. First of all, let me immediately make clear that I do not think of them as supermen or even as men who are in any way morally superior. They are like their fellow humans, sharing the same passions and weaknesses but they have learned to use the appendages on their necks a little better, or at least differently, from other men.

This skill is not too painful to acquire, but it demands some courage and some effort. The novice must be prepared to try to look at things in a detached way and to use his intellectual faculties, even if they sometimes collide with his desires. He must try to be honest with himself. ‘Bleibe Dir selbst treu’ (To thine own self be true) was a principle emphasized by Max Planck, although it was not original with him.

The results reaped by the scientific habit of mind have been impressive even with respect to some of the serious political problems confronting us all.

Scientists over the whole earth have been able to converse easily with each other. I do not think that this is due as much to their having the common language of mathematics as to their common mental attitude.

To a large extent, they have escaped some of the worst aberrations and collective insanities that have afflicted mankind in recent years, and when the very foundations of civilization seemed in peril they generously welcomed their fellow scientists to the islands of safety then prevailing. I, for one, cannot forget my debt of gratitude for this.

They have been able to select and appreciate good things in their field wherever they were to be found, and thus brought about true international cooperation. If my English is not perfect (as you see, I am an optimist) my colleagues have consoled themselves with my passable knowledge of Italian, and similarly I have been able to help scientifically just because my physics was in many ways different in outlook from what I learned in California.

Finally, scientists have tried to alert everybody to the serious dangers we are facing and have spent much effort and energy in order to make these dangers clear to governments and populations.

I think that this attitude which I have briefly outlined is one of the most valuable aspects of science and the humanitarian Nobel might have liked to see these prizes foster not only great intellectual and technical achievements but also this way of thinking and living which perhaps approaches his lofty ideals.

Once more my deep gratitude.

© the Nobel Foundation 1960

M. Segrè — Second Address
Seven LBL Nobel laureates, posed in front of Ernest Lawrence’s 37-inch cyclotron magnet. Left to right are Owen Chamberlain, Edwin McMillan, Emilio Segr&egrave, Melvin Calvin, Donald Glaser, Luis Alvarez and Glenn Seaborg. March 7, 1969.
Students, Ladies and Gentlemen:
Although we have a poet in our midst who would be far more eloquent than I could be, I’ve been chosen to answer your gracious and heart-felt greeting, and I will do my best.

We Nobel laureates, although we work in widely diversified fields, share at least one thing in common: we spend a good part of our lives 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.

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’m going to tell you. Perhaps it’s Swedish and so you may have already heard it. The person who taught it to me was an old Quaker lady from Pennsylvania.

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.

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

Much to their consternation they found that there was no island in the pond of cream. 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 were 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 so he was saved.

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

© the Nobel Foundation 1960
• Biography Submitted by Dr. Segrè to the Nobel Committee

Dr. Emilio Segr&egrave, May 1954.
Born in Tivoli (Rome) on February 1, 1905, son of Giuseppe Segrè, industrialist, and Amelia Segrè Treves. Went to school in Tivoli and Rome. Entered University of Rome as a student of engineering in 1922. Transferred to the study of physics in 1927 and took his Doctor’s degree in 1928 under Professor Fermi. His was the first Doctor’s degree conferred under the sponsorship of Professor Fermi.

Served in the Italian Army in 1928 and 1929 and entered the University of Rome as assistant to Professor Corbino in 1929. In 1930 he had a Rockefeller Foundation Fellowship and worked with Professor Otto Stern at Hamburg, Germany, and Professor Pieter Zeeman at Amsterdam, Holland. In 1932 returned to Italy and was appointed Assistant Professor at the University of Rome, working continuously with Professor Fermi and others.

In 1936 Professor Segrè was appointed Director of the Physics Laboratory at the University of Palermo and remained there until 1938.

In 1938 Professor Segrè came to Berkeley, California, first as a research associate in the Radiation Laboratory and later as a lecturer in the Physics Department. From 1943 to 1946 he was a group leader in the Los Alamos Laboratory of the Manhattan District. In 1946 he returned to the University of California at Berkeley as a Professor of Physics, and still occupies this position.

The work of Professor Segrè has been mainly in atomic physics and nuclear physics. In the first field he worked in atomic spectroscopy, making contributions to the spectroscopy of forbidden lines and the study of the Zeeman effect. Except for a short interlude on molecular beams, all his work until 1934 was in atomic spectroscopy. In 1934 he started the work in nuclear physics by collaborating with Professor Fermi on neutron research. He participated in the discovery of slow neutrons and in the pioneer neutron work carried on in Rome 1934-35. Later he was interested in radio chemistry and discovered together with Professor Perrier the element technetium; together with Corson and Mackenzie the element astatine, and together with Kennedy, Seaborg and Wahl, plutonium-239 and its fission properties. His other investigations in nuclear physics cover many subjects, e.g., isomerism, spontaneous fission, and lately, high energy physics: here he, his associates and students, have made contributions to the study of the interaction between nucleons and on the related polarization phenomena. In 1955 together with Chamberlain, Wiegand and Ypsilantis he discovered the antiproton. The study of antinucleons is now his major subject of research.

Professor Segrè has taught in temporary appointments at Columbia University, New York, at the University of Illinois, at the University of Rio de Janeiro and in several other institutions. He is a member of the National Academy of Science of the United States, of the Academy of Science at Heidelberg (Germany), of the Accademia Nazionale dei Lincei of Italy, and of other learned societies. He has received the Hofmann Medal of the German Chemical Society and the Cannizzaro Medal of the Italian Accademia dei Lincei. He is an honorary Professor of San Marcos University in Peru and is Dr. h.c. of the University of Palermo (Italy). Together with Owen Chamberlain, he received the Nobel Prize in physics for 1959 for the discovery of the antiproton. Professor Segrè is married and has three children.

[Dr. Segrè died in 1989]

© the Nobel Foundation 1960

• Biography Submitted by Dr. Chamberlain to the Nobel Committee

Dr. Owen Chamberlain, November 1955.
Owen Chamberlain was born in San Francisco on July 10, 1920. His father was W. Edward Chamberlain, a prominent radiologist with an interest in physics. His mother’s maiden name was Genevieve Lucinda Owen.

He obtained his bachelor’s degree at Dartmouth College in 1941. He entered graduate school in physics at the University of California, but his studies were interrupted by the involvement of the United States in World War II. In early 1942 he joined the Manhattan Project, the U.S. Government organization for the construction of the atomic bomb. Within the Manhattan Project he worked under Professor Emilio Segrè both in Berkeley, California, and in Los Alamos, New Mexico, investigating nuclear cross sections for intermediate-energy neutrons and the spontaneous fission of heavy elements. In 1946 he resumed graduate work at the University of Chicago where, under the inspired guidance of the late Professor Enrico Fermi, he worked toward his doctorate. He completed experimental work on the diffraction of slow neutrons in liquids in 1948 and his doctor’s degree was awarded in 1949 by the University of Chicago.

In 1948 he accepted a teaching position at the University of California in Berkeley. His research work includes extensive studies of proton-proton scattering, undertaken with Professor Segrè and Dr. Clyde Wiegand, and a important series of experiments on polarization effects in proton scattering culminating in the triple-scattering experiments with Professor Segrè, Dr. Wiegand, Dr. Thomas Ypsilantis, and Dr. Robert D. Tripp. In 1955 he participated with Dr. Wiegand, Professor Segrè, and Dr. Ypsilantis in the discovery of the antiproton. Since that time he has taken part in a number of experiments designed to determine the interactions of antiprotons with hydrogen and deuterium, the production of antineutrons from antiprotons and the scattering of pi mesons.

He is a fellow of the American Physical Society and was awarded a Guggenheim fellowship in 1957 for the purpose of doing studies in the physics of antinucleons at the University of Rome. He was appointed Professor of Physics at the University of California, Berkeley, in 1958.

In 1943 he married Beatrice Babette Copper. He has three daughters and one son.

© the Nobel Foundation 1960

Ernest Orlando Lawrence Berkeley National Laboratory
Last modified Tuesday, 23-Mar-2010 14:51:11 PDT