Theory Versus Experiment: The Case of the Positron

The history of positron discovery is an interesting case-study of complex relationship between theory and experiment, and therefore could promote understanding of a key issue on the nature of science (NoS) within a learning environment. As it is well known we had indeed a theory, P.A.M. Dirac’s theory of the anti-electron (1931), before the beginning of the experiments leading to the experimental discovery of the positive electron (Anderson, 1932). Yet, this case is not merely an instance of successful corroboration of a theoretical prediction since, as it will be shown, the man who made the discovery, Anderson, actually did not know from the start what to look for.