Proceedings of the International Conference “Enrico Fermi and the Universe of Physics” Rome, September 29 – October 2, 2001 Ministero per i Beni e le Attività Culturali Direzione Generale per i Beni Librari e gli Istituti Culturali Comitato Nazionale per le celebrazioni del centenario della nascita di Enrico Fermi Proceedings of the International Conference “Enrico Fermi and the Universe of Physics” Rome, September 29 – October 2, 2001 Accademia Nazionale dei Lincei Istituto Nazionale di Fisica Nucleare SIPS Proceedings of the International Conference “Enrico Fermi and the Universe of Physics” Rome, September 29 – October 2, 2001 2003 ENEA Ente per le Nuove tecnologie, l’Energia e l’Ambiente Lungotevere Thaon di Revel, 76 00196 - Roma ISBN 88-8286-032-9 Honour Committee Rettore dell’Università di Roma “La Sapienza” Rettore dell’Università degli Studi di Roma “Tor Vergata” Rettore della Terza Università degli Studi di Roma Presidente del Consiglio Nazionale delle Ricerche (CNR) Presidente dell’Ente per le Nuove tecnologie, l’Energia e l’Ambiente (ENEA) Presidente dell’Istituto Nazionale di Fisica Nucleare (INFN) Direttore Generale del Consiglio Europeo di Ricerche Nucleari (CERN) Presidente dell’Istituto Nazionale di Fisica della Materia (INFM) Presidente dell’Agenzia Italiana Nucleare (AIN) Presidente della European Physical Society (EPS) Presidente dell’Accademia Nazionale dei Lincei Presidente dell’Accademia Nazionale delle Scienze detta dei XL Presidente della Società Italiana di Fisica (SIF) Presidente della Società Italiana per il Progresso delle Scienze (SIPS) Direttore del Dipartimento di Fisica dell’Università di Roma “La Sapienza” Index 009 A Short Presentation of the Fermi Centennial Conference Carlo Bernardini 013 Enrico Fermi: a Guiding Light in an Anguished Century Giorgio Salvini 033 Fermi’s Contribution to the World Energy Supply Carlo Rubbia 043 Enrico Fermi and his Family Alice Caton 053 The Birth and Early Days of the Fermi Group in Rome Gerald Holton 071 Fermi toward Quantum Statistics (1923-1925) Fabio Sebastiani, Francesco Cordella 097 The Evolution of Fermi’s Statistical Theory of Atoms Jan Philip Solovej 105 Nuclear Physics at the Cavendish Laboratory in the Thirties Jeff Hughes 119 Cooperation and Competition among Nuclear Physics Laboratories during the Thirties: the Role of Frédéric Joliot Michel Pinault 133 From Fermi to Fission: Meitner, Hahn and Strassmann in Berlin Ruth Lewin Sime 145 Slow Neutrons at Via Panisperna: the Discovery, the Production of Isotopes and the Birth of Nuclear Medicine Ugo Amaldi 169 Funds and Failures: the Political Economy of Fermi’s Group Giovanni Battimelli 185 Fermi and Quantum Electrodynamics (QED) Sam Schweber 7 217 Fermi and Applied Nuclear Physics during the War (1939-1945) Michelangelo De Maria 219 New Large Accelerators in the World in the Forties and Early Fifties Dominique Pestre 221 Enrico Fermi and the Birth of High-Energy Physics after World War II Giulio Maltese 259 Enrico Fermi, High-Energy Physics and High Speed Computing Robert Seidel 269 Women in Physics in Fermi’s Time Nina Byers 289 Documents on Fermi’s Life Harold Agnew 295 Fermi and the Ergodic Problem Giovanni Gallavotti 303 Fermi and General Relativity Tullio Regge 305 Fermi’s Tentativo and Weak Interactions Nicola Cabibbo 317 Enrico Fermi, the Man. Excerpts from some documents Jay Orear 341 Experimental Nuclear Physics in the Thirties and Forties John L. Heilbron 361 The Beginnings of Pion and Muon Physics Leon Lederman 365 Perspectives in High Energy Particle Physics Luciano Maiani 389 Enrico Fermi Chen Ning Yang 395 Concluding Remarks Giorgio Salvini 399 Report on the Celebrations for the Centenary of Enrico Fermi’s Birth Carlo Bernardini, Rocco Capasso 8 A Short Presentation of the Fermi Centennial Conference Carlo Bernardini nrico Fermi was born on September 29, 1901; he died on November 28, E1954: a very short life indeed. Nevertheless, his scientific legacy is by far richer than that of most physicists in the last century. This can be easily appreciated by the extremely frequent recurrence of his name in most topics of the so called “modern” physics: Fermi coordinates, Fermi-Dirac statistics, fermions, Fermi-Thomas atom, Fermi motion, Fermi surface, Fermi energy, Fermi’s golden rule, Fermi constant, Fermi theory of beta decay, fermi as a unit of length, Fermi age of neutrons, and so on (it is common to forget some in this list). This also shows that his fields of interest went from gener- al relativity to statistical mechanics, from atomic physics to solid state, from quantum electrodynamics to nuclear physics, from elementary particles to astrophysics: actually, there is no field of modern physics in which Fermi did not contribute in a memorable way. This, I believe, is the reason why so many distinguished people agreed to contribute to this Conference: everybody had, in some way, to pay a debt to an undisputed master of the 20th century, both the organizers and the speakers. Italy is a nice country, beloved by visitors from abroad because of monu- ments, museums, climate, perhaps people; arts and literature are apparently the most congenial activities to the population. At first, it might seem that science doesn’t have a central role, if any, in the Italian culture; therefore, the sudden appearance of such outstanding personalities as Galilei or Fermi (and many others, indeed) looks like a miracle. Undoubtedly, this is a good rea- son to examine how and why the “miracle” happened and to illustrate, par- ticularly to Italians, that it is perfectly possible at any moment to repeat the prodigy. With this in mind, some years ago the old and glorious Società Italiana per il Progresso delle Scienze (SIPS, of which Fermi was a member) decided to ask government financial support to invite people of the interna- tional physics community in some way or other related to Fermi, to recon- struct in a public occasion both the achievements of the Scientist and the cir- cumstances in which his activity developed. 9 Thanks to the above-mentioned far-sightedness of SIPS, the Ministero dei Beni Culturali (especially the general director, Francesco Sicilia, who was extremely cooperative) gave us the opportunity to organize a National Committee and I had the honor to chair it with the task to prepare a detailed proposal. I accepted in the second half of 1999, well knowing that it is extremely difficult to do “the best”. Now that the event is concluded, I can and want to say that I would never had reached any result without the invaluable help of Rocco Capasso, secretary-general of SIPS, and Luisa Bonolis, who had a special grant from the INFN (Istituto Nazionale di Fisica Nucleare) to assist the activity of the Comitato. It was decided from the very beginning that the Accademia Nazionale dei Lincei should have a role in the organization of the Conference, so that the Comitato agreed in assigning a part of the program (about one third) to a special commission of the Accademia. During and after the Conference an Exhibition was open to the public con- taining some documents, pictures, films and original instruments; the Exhibition was installed in a theather in Rome, the “Teatro dei Dioscuri” near the Presidential residence at the Quirinale. The President of the Italian Republic actually was the first visitor of the Exhibition at the opening cere- mony, on September 29, 2001. A large representation of the Fermi family, up to the great-granddaughter Ishbel who delighted all people present, had been there since a couple of days before, because of a ceremony we had pro- moted in via Gaeta 19, were Enrico was born; also, many members of the Capon family were there, the family of Laura Fermi. The conference was, in my opinion, very satisfactory; all the aspects of the scientific activity of Enrico Fermi were considered and the peculiarities of his approach to the problems were analyzed. Here you can find the written ver- sion of the talks that, all together, constitute an important recollection of original thoughts on Fermi’s ideas, Fermi’s role, Fermi’s time. Almost all the speakers have sent their text in due time to allow a quick preparation of the Proceedings thanks to the full commitment of Diana Savelli and ENEA (Ente per le Nuove tecnologie, l’Energia e l’Ambiente) helped by Rocco Capasso of SIPS and Giovanna Dall’Ongaro (who was engaged by the Comitato in the Conference Secretariat). Professor Chen Ning Yang and professor Leon Lederman, who were not able to join the Conference because of the serious difficulties with international flights after September 11, 2001, were both so kind as to mail a short written contribution to the event: we are very grateful to them for their intention to participate in difficult moments. 10 A lot of open questions arise when examining Fermi’s life: why was he such a precocious child? Which were the books he studied? Where came his inter- est in analytical mechanics from? How was he able to get a chair in theoret- ical physics at the age of 25 in a hostile academic surrounding? Where did he get the idea of his statistics? How did he became quickly reknown in the international physics community and which were his relations with English, Germans and French laboratories? What was his genuine con- tribution to the new-born Quantum Electrodynamics and how did this prel- ude to the theory of beta decay? Why did he decide to convert from atomic to nuclear physics? How did he understand slow neutrons? Why did his group miss uranium fission? How was he able to realize the first nuclear reac- tor in such a short time? What was his contribution at Los Alamos? What was his commitment in political decisions at and after the end of WWII? What were his ideas in elementary particle physics? What the problems he con- tributed to in astrophysics? What his suggestions for helping Italian physics to restart after the war? How and why did he become interested in comput- ing devices? All these questions will find answers in the Proceedings of this Conference; this is the reason why I feel very indebted to all the speakers and want to express my gratitude to all of them and to the colleagues who chaired the sessions and conducted the discussion.