Notes on Italian Physics between the two World Wars

For various reasons (cultural, economical, etc.) related to a long history (starting perhaps from Galileo’s times), Italian physics at the beginning of XXth century was not particularly advanced. This was mirrored in the very slow diffusion, as regard education as well research programs, of new revolutionary theories such as relativity and old quantum theory. But in a few decades this gap was more or less filled, thanks to a new generation of young outstanding scientists (first of all, Enrico Fermi and Bruno Rossi), and to the far-sightedness of some influential scientists holding important political positions (such as Orso Mario Corbino and Giorgio Antonio Garbasso). I will present here, in a very schematic way, the main contributions and the prominent figures in this “renaissance” of Italian physics. In particular, I will focus on some fundamental aspects of the activity of the two physicists who promoted, in the 1930s, nuclear and subnuclear physics in Italy: Enrico Fermi and Bruno Rossi. The first was the leader of the Rome school, mainly devoted to theoretical and experimental nuclear physics, and the latter was the founder of the Italian cosmic-ray school. 1938, the year of the infamous fascist racial laws, marks the beginning of the dispersion when, as it is well known, the roads of many Italian physicists diverged: some, like Amaldi and Bernardini, stayed in Italy to keep the research alive; others, like Rossi and Fermi themselves, Occhialini, Rasetti and many others emigrated.