ESHS/HSS Annual Meeting

Bruno Rossi and the chambers of secrets: evolution of cosmic-ray techniques in the interwar period

• In Event: Through Archival and Material Sources: New Perspectives in the History of Physics (19th–20th Centuries)

English Abstract

In the late 1920s and, most noticeably, in the 1930s, the experimental practices for studying cosmic rays evolved significantly, enabling physicists to address their composition and behaviour. From ionization chambers to Geiger-Müller counter tubes and cloud chambers, the phenomenology of this new kind of radiation was recorded in multiple and complementary ways.
In this talk, I will start from the case study of the cloud chamber built under the supervision of Professor Bruno Benedetto Rossi (1905-1993)—one of the parents of cosmic-ray physics—at the University of Padua, now on display at the “Giovanni Poleni” Museum. This instrument had an unusually long and tumultuous life, marked by numerous modifications and decades of debate over its authorship. After situating its life within the partially overlooked panorama of the few Italian cloud chambers built during that period, I will reconstruct the complex interplay between these different kinds of cosmic-ray detectors over time. For instance, Rossi himself—most famous for his work with counters alone—performed measurements with them throughout his career, exploring their versatility and potential, as well as their limits. Sometimes single protagonists of entire surveys, sometimes combined, their history is entangled with the process that led to the birth of particle physics.
The main goal of this contribution is to examine how cosmic-ray physicists like Rossi reinvented the scope and role of these chambers multiple times, giving rise to an interesting and fruitful interweaving of scientific practices.

Author

• Luca Campagnoni, University of Padua