Christian Joas: Many-body Physics and Transfer of Knowledge in Postwar Physics, c. 1950–1970

Based on several case studies, the project analyzes mechanisms of knowledge transfer between the emerging subdisciplines of physics in the first two decades after World War II. After the War, physics underwent momentous changes and many of today’s well-established subdisciplines of physics—such as particle, nuclear, or solid-state physics—gained an identity of their own, both institutionally and intellectually. The entailing specialization of physicists led to an emergence of increasingly diverging research practices: actors from different subdisciplines began using different terminologies, methods, and techniques.

Mottelson, Mayer, Jensen, and Aage Bohr at a 1957 conference in Rehovot.

The project aims at studying this inner tension in the history of postwar physics through a historical-epistemological analysis of processes of knowledge transfer across the emerging subdisciplinary boundaries. The main focus lies on quantum many-body physics, a hybrid field of research that, during the 1950s and 1960s, attracted physicists of various subdisciplinary backgrounds and thus enabled transfer of knowledge. Among the cases studied are the Bohm-Pines collective theory of the electron gas in metals, Bohr-Mottelson nuclear structure theory (developed chiefly here in Copenhagen), Brueckner many-body theory, quantum field theoretic methods for the treatment of solids, and spontaneously broken symmetries in both solid-state and particle physics.