Observability, Unobservability and the Copenhagen Interpretation in Dirac's Methodology of Physics

TL;DR

This paper reevaluates Dirac's philosophical stance, arguing he was not strictly a positivist or Copenhagen supporter, and highlights his diverse and sometimes contradictory methodological principles in quantum physics.

Contribution

It challenges the common view of Dirac as a Copenhagen supporter by analyzing his works and revealing his varied philosophical approaches.

Findings

Dirac's work does not align strictly with positivism.

He employed diverse and sometimes contradictory methodologies.

He should be disentangled from the Copenhagen interpretation.

Abstract

Paul A. M. Dirac has been undoubtedly one of the central figures of the last century physics, contributing in several and remarkable ways to the development of Quantum Mechanics (QM); he was also at the centre of an active community of physicists, with whom he had extensive interactions and correspondence. In particular, the British physicist was in close contact with Bohr, Heisenberg and Pauli. For this reason, among others, Dirac is generally considered a supporter of the Copenhagen interpretation of QM. Similarly, he was considered a physicist sympathetic with the positivistic attitude which shaped the development of quantum theory in the twenties. Against this background, the aim of the present essay is twofold: on the one hand, we will argue that, analyzing specific examples taken from Dirac's published works, he can neither be considered a positivist nor a physicist methodologically guided by the observability doctrine. On the other hand, we will try to disentangle Dirac's figure from the mentioned Copenhagen interpretation, since in his long career he employed remarkably different - and often contradicting - methodological principles and philosophical perspectives with respect to those followed by the supporters of that interpretation.