"Lectures on pions and nucleons"

special issue dedicated to E. FERMI

Rivista del Nuovo Cimento Vol. 31, N. 1 (2008).

DOI 10.1393/ncr/i2008-10029-9

Preface by L. Cifarelli

In 1953, Giovanni Polvani, President of the Italian Physical Society (Società Italiana di Fisica, SIF) appointed Giampietro Puppi, from the University of Padua, to organize the first Course of the International School of Physics of the Society.

The seat of the School was chosen to be Villa Monastero in Varenna, a most beautiful and characteristic village in the eastern bank of Como Lake. Villa Monastero, once a monastery then transformed into a residential palace, is one of the most ancient and famous villas of the region with a magnificent botanic garden. All physicists who have been there cannot but remember a superb centuries-old magnolia tree whose fronds dive into the clear waters of the lake.

The 1953 Course was focused on the contribution from cosmic rays to elementary particle physics. Patrick M. S. Blackett and Cecil Powell were invited to lecture in Varenna. The School was indeed very successful and it was decided by SIF to ask Giampietro Puppi to organize a second Course in 1954.

This second Course was again devoted to elementary particle physics but the emphasis was on the contribution from existing and planned accelerators. In his opening address Puppi, illustrating other future physics Courses to be possibly held in Varenna, said, "Per ora accontentiamoci delle particelle elementari e più propriamente seguiamole nei fenomeni di grande energia, in quel fantastico mondo nel quale tutto si svolge in volumetti di spazio incredibilmente piccoli e in intervalli di tempo straordinariamente brevi, ma portando in gioco energie tali che, se si potessero ridurre in scala, macroscopicamente, risulterebbero spaventose." ("For the time being let us content ourselves with elementary particles and more properly let us follow them in high-energy phenomena, in that fantastic world where everything happens in tiny volumes of space incredibly small and in time intervals extraordinarily short, involving however energies which, if macroscopically scaled, would appear as frightening.")

To illustrate this "fantastic world", a selected board of distinguished lecturers was called for the 1954 Course and an intense programme established. Enrico Fermi and Werner Heinsenberg gave the first two lectures of a series on the physics of pions and nucleons. Gilberto Bernardini, Bernard T. Feld and others took care of a second group of lectures on photoproduction. Bruno Rossi lectured on fundamental particles and on the origin of cosmic rays. Various particle accelerator facilities and projects in different laboratories in Europe were illustrated by a number of world experts. A selected group of about 40 students attended this Course.

In his opening address of 1954, Puppi presented the lecturers and the main subjects of the School to trigger the interest of the students, just floodlighting the relevance of Fermi's lectures: "E` di questa Fisica dei nucleoni e dei mesoni pi che desidero parlarvi oggi, della sua evoluzione, delle prospettive future, della sua importanza nella economia del nostro Universo e del nostro sapere". ("It is about this Physics of nucleons and mesons pi that I wish to talk to you today, about its evolution, about its future perspectives, about its relevance in the economy of our Universe and of our knowledge".)

Fermi gave 16 lectures on the subject of pions and nucleons, from the 19th of July up to the 6th of August 1954. He left Varenna the next day. His lectures were recorded on magnetic tape and transcribed by the students. Although he had checked this transcription during his stay in Varenna all the way long, on the eve of his departure Fermi expressed to Polvani, his worry about the transcribed text that he had no time to rearrange in what he considered a due form for publication in the Proceedings.

Fermi passed away a few months later.

Exactly one year after his last lecture in Varenna, on the 6th of August 1955, an official commemorative ceremony was organized by President Polvani, in the presence of Fermi's wife, Mrs. Laura Fermi Capon, and Fermi's sister, Mrs. Maria Sacchetti Fermi. During the first phase of the ceremony, in Varenna, a porphyry plaque bearing a Latin epigraph and a bronze medallion with his low-relief effigy were unveiled in memory and in honour of Enrico Fermi in the Aula of Villa Monastero.

The second phase of the ceremony took place in Como at the Tempio Voltiano, where Isidor I. Rabi was invited to give the official commemorative address in honour of Enrico Fermi. On that occasion the volume of the Proceedings of the International School of Physics, Varenna 1954, Course II, edited by G. Puppi and dedicated to E. Fermi, was presented. Copies were offered to Mrs. Fermi, Mrs. Sacchetti and to the authorities. President Polvani also announced that the School would be named after Enrico Fermi. The SIF School is now worldwide known as the International School of Physics "Enrico Fermi".

On the 70th anniversary of the Nobel Prize award to Enrico Fermi in 1938, the Italian Physical Society is reprinting in this special issue of La Rivista del Nuovo Cimento the original Lectures on Pion and Nucleons by Enrico Fermi.

Much has been said and written about the outstanding quality of these lectures, starting from the early witness by Feld in his preface. The discussion and perspective on nuclear forces these lectures contain make them an exemplar reference in scientific literature. In this respect let me just report the touching words of Rabi during his address of 1955 in Como: "Here in Italy where his memory is so alive and where so many have heard Fermi lecture I do not have to describe the remarkable fascination he could induce in any audience. He used no histrionics in his delivery. It was always calm and deliberate. The fascination lay in the feeling of clarity and simplicity he could impart to the audience. They felt illuminated and had the sense of participating in profound and beautiful insight." This is what Fermi's lectures still inspire.

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