Franco Rasetti (1901–2001) Studying High-Energy Cosmic Rays, and Had Measured the Half-Life of the Recently

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Obituary last graduate student at Laval. He had developed equipment and techniques for Franco Rasetti (1901–2001) studying high-energy cosmic rays, and had measured the half-life of the recently

When Franco Rasetti died on 5 December discovered particle, the p meson. Just as AIP 2001, the scientific world lost one of its in Rome, his inventions and techniques most prolific generalists. Rasetti was a were duplicated in many laboratories. member, with Enrico Fermi, of Italy’s In Canada, Rasetti continued his life- celebrated ‘via Panisperna’ research group long habits of walking and mountain- in the 1930s. He was an acknowledged climbing. An interest in Canadian geology authority not only in spectroscopy, led him into palaeontology and then to nuclear physics and cosmic radiation, but trilobites — fossilized marine creatures also in palaeontology and botany. He of the Cambrian era. Rasetti came to be a made valuable contributions in optics and major influence on the palaeontological entomology; published scores of papers; scene. He sought out trilobite fossils collected, classified and named hundreds everywhere, collecting thousands of of palaeontological specimens; and his specimens, which he described, classified book on Alpine flora has sold tens of and in many cases named. He developed thousands of copies. techniques for preserving and Rasetti was born in Pozzuolo Umbro, photographing them for journals, and his Italy. He inherited a flair for natural collection rivalled that of Washington’s science — his father was a professor of Smithsonian Institution. Just as he had agricultural entomology and botany, and been honoured for his work on nuclear his mother was an accomplished artist, Physicist and physics and Raman spectroscopy, Rasetti specializing in entomology. They educated palaeontologist received numerous awards for his the young Franco themselves. At just contributions to palaeontology; for seventeen, he published his first paper, holder — and eventually to the example, in 1952 he won the Charles on the insects of Pisa and Lucca. development of nuclear reactors and Doolittle Walcott Pre-Cambrian Research When the family moved to Pisa, Rasetti a multi-billion-dollar industry. Medal, which is awarded every five years met a young Roman called Enrico Fermi. In the midst of this activity, Rasetti by the US National Academy of Sciences. Fermi encouraged Rasetti to study physics managed to spend some time at the At the end of the Second World War, rather than entomology and, on long walks, California Institute of Technology in Rasetti finally moved to the United States, the two engaged in furious debates about Pasadena. There, he cobbled together leaving Laval for Johns Hopkins scientific disciplines. In the end, Fermi won equipment to investigate the newly University. There his research centred on Rasetti over, and the two enrolled in the discovered Raman effect — the imprint on radioactivity, particularly the gamma-ray sparsely attended postwar physics course scattered light of the vibrational levels of a spectra and decay schemes of thorium, at the Pisa Institute. Rasetti then moved to medium’s molecules. His studies in 1929 of ionium and radon. In 1949 he married Florence where he completed his PhD. the effect in hydrogen, oxygen and nitrogen Marie Madeline Hennin, a Belgian he had The friendship between the two were hailed as the year’s outstanding work previously met in Québec. The couple matured into a fruitful professional in spectroscopy. His famous spectrum of retired to Waremme, Belgium, in 1977, collaboration. Rasetti was the master of the Raman effect in nitrogen has been and it was there that Franco Rasetti died, experimental work, whereas Fermi had reproduced in many texts. aged 100. a more theoretical bent. By 1927 their As the storm clouds of the Second Today, we hear a great deal about reputation had grown such that Orso World War gathered, research conditions scientific fraud, and commissions and Mario Corbino invited them to join him in Italy became difficult. In 1938, Segrè committees on scientific ethics abound. at the Physics Institute of Rome. With and Fermi left for the United States; For Rasetti, scientific honesty was Edoardo Amaldi, Emilio Segrè and Rasetti was courted by Université Laval in axiomatic and automatic. We speak of Oscar D’Agostino, they became the Québec, Canada, as well as several larger research teams and networks of research famous via Panisperna group — named US institutions. He chose Laval to avoid groups, but Rasetti considered that the after the address of the institute — which becoming involved in war-related research autonomy and independence of the was to revolutionize Italian, and indeed — unlike his friend Fermi, who became a individual scientist were paramount. international, physics. central figure in the Allied project to We hear of national scientific strategies Inspired by Rasetti and Fermi, the develop the nuclear bomb. Rasetti was and policies, but Franco Rasetti resisted group developed research programmes, not a pacifist: his objections to the war politics, believing that the fruits of science enrolled graduate students and visited were not moral or political, rather, he were for all humanity. other laboratories. They imported simply considered war to be foolish and His work and writing are noted for the experimental techniques — and invented did not wish to be involved. elegance, simplicity and beauty which he and exported their own. In particular they On his arrival at Laval in 1939, Rasetti considered to be the innate characteristics started investigating the transmutation of was given the daunting task of creating a of science. Several books and biographies elements by neutron bombardment. They physics department from scratch. But attest to this, most recently the biography quickly discovered sixty new radioactive within eight years a solid physics by Danielle Ouellet and René Bureau: nuclei and used slow neutrons to induce programme was turning out dozens of Franco Rasetti — physicien et naturaliste the fission of uranium. This work led to honours students, and research was (Guérin, 2000). Larkin Kerwin the patent of the chain-reaction process — burgeoning in several fields. It was at this Larkin Kerwin is Professor Emeritus at Université of which Rasetti was the last surviving time that I met Rasetti, and became his Laval, Québec G1K 7P4, Canada.