Quantum Theory at the Crossroads: Reconsidering the 1927 Solvay Conference

TL;DR

This paper revisits the 1927 Solvay conference, revealing that the interpretation of quantum mechanics was unresolved then and remains open today, by translating original proceedings and analyzing diverse perspectives in light of current debates.

Contribution

It provides the first complete English translation of the 1927 proceedings and offers a detailed analysis of the conflicting interpretations discussed, emphasizing the ongoing relevance of historical debates.

Findings

No consensus was reached at the 1927 conference on quantum interpretation.

The proceedings include extensive discussions of de Broglie's pilot-wave theory.

The conference revealed a lack of agreement on wave function collapse and time evolution.

Abstract

We reconsider the crucial 1927 Solvay conference in the context of current research in the foundations of quantum theory. Contrary to folklore, the interpretation question was not settled at this conference and no consensus was reached; instead, a range of sharply conflicting views were presented and extensively discussed. Today, there is no longer an established or dominant interpretation of quantum theory, so it is important to re-evaluate the historical sources and keep the interpretation debate open. In this spirit, we provide a complete English translation of the original proceedings (lectures and discussions), and give background essays on the three main interpretations presented: de Broglie's pilot-wave theory, Born and Heisenberg's quantum mechanics, and Schroedinger's wave mechanics. We provide an extensive analysis of the lectures and discussions that took place, in the light of current debates about the meaning of quantum theory. The proceedings contain much unexpected material, including extensive discussions of de Broglie's pilot-wave theory (which de Broglie presented for a many-body system), and a "quantum mechanics" apparently lacking in wave function collapse or fundamental time evolution. We hope that the book will contribute to the ongoing revival of research in quantum foundations, as well as stimulate a reconsideration of the historical development of quantum physics. A more detailed description of the book may be found in the Preface. (Copyright by Cambridge University Press (ISBN: 9780521814218).)