Ciao Jack!

Jack Steinberger passed away on December 12, 2020, aged 99. My last personal recollections about him are all connected to his presence at most – if not all – of the seminars organized at CERN in the Main Auditorium. Owing to his inexhaustible curiosity, he wouldn't have missed even one! We also used to go skiing together in the French Alps, many, many years ago, with a group of common German friends. He was able to ski even after a hip surgery like it was nothing. And memorable was his answer once to my "how are you" greeting question when meeting him at the CERN cafeteria: "Fine! But this is only part of the answer". I often quote it and sometimes dare to use it myself.

Many obituaries have been written for Jack Steinberger, celebrating the man and the scientist, namely his outstanding research work that earned him the 1988 Nobel Prize in Physics, along with Leon M. Lederman and Melvin Schwartz, for the discovery of the muon neutrino.

What I would like to recall here is his presence in Varenna, Como Lake, Italy, in the beautiful venue of Villa Monastero, at the International School of Physics of the Italian Physical Society (SIF) in 1954. This was his first participation in the School. He was accompanying Enrico Fermi, under whose supervision he had received his PhD in 1948 at the University of Chicago. Fermi was an invited lecturer at the School.

The Varenna Summer School had been established in 1953, just one year earlier, under the initiative of the then SIF President Giovanni Polvani. The 1^st course of the School was titled: "Issues related to elementary-particle detection, with special attention to cosmic radiation". The course was directed by Giampietro Puppi and the lecturers were outstanding scientists like Cecil Powell, Patrick Blackett, Hannes Alfvén, Giuseppe (Beppo) Occhialini, to name but a few. This 1^st course was a real success, to the extent that Puppi was asked to direct another one in the Summer of 1954. The title of the 2^nd course was: "The contribution from existing and planned accelerators to elementary particles physics". Again, eminent physicists were invited to lecture, among them Enrico Fermi, Werner Heisenberg, Gilberto Bernardini and Bruno Rossi. Enrico Fermi and Werner Heinsenberg gave the first two lectures of a series on the physics of pions and nucleons. Gilberto Bernardini, Bernard 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, from Edoardo Amaldi, to John Adams, Gerhard Lüders, Gerry Pickavance, Robert Lévy-Mandel and Giorgio Salvini. Fermi actually gave a total of 16 lectures in Varenna from July 16 to August 6, 1954. This was his last gift to Italy. He passed away a few months later. One year after Fermi’s premature death, the School was named after him.

Jack Steinberger in the Fermi Lecture Hall at Villa Monastero, Varenna, in 2013.

Jack Steinberger came back to Varenna several times since then: in 1964, 1967 and 2013. In 2013 the “Enrico Fermi” School celebrated its 60^th anniversary with a special symposium titled "Passion for Physics". Jack gave a talk on "Personal recollections of Varenna: Physics, Fermi, mountains". Why mountains? Because he had always enjoyed mountaineering and he showed with proud to the audience his card of honorary member of the Club Alpino Italiano, mentioning the beautiful climbing he had been doing in his youth in the spectacular surroundings of Varenna. He recalled Fermi and the "extreme privilege" he had to be with him in Chicago in the years 1946-1948, just after the war, pointing out in particular the "extraordinary kindness of Fermi to his students".

On that occasion, he gave me the nice photograph – reproduced here as cover image for this article – which shows Fermi sitting on the steps of the Villa at the lake water’s edge among the School students. Jack is there, in a bathing suit since at the time students were allowed to go swimming directly from the little pier of the Villa (which is no more possible, alas, for safety reasons).

At the end of his talk at the symposium, Jack sat on the marble steps of the lecture hall of Villa Monastero to answer the many questions coming from the audience, as shown in the above snapshot. He seemed to relax and enjoy the event. This is how we want to remember him.

Ciao Jack!