Quantum Theory at the Crossroads Reconsidering the 1927 Solvay Conference

The 1927 Solvay conference was perhaps the most important in the history of quantum theory. Contrary to popular belief, questions of interpretation were not settled at this conference. Instead, a range of sharply conflicting views were extensively discussed, including de Broglie's pilot-wave theory (which de Broglie presented for a many-body system), Born and Heisenberg's 'quantum mechanics' (which apparently lacked wave function collapse or fundamental time evolution), and Schrödinger's wave mechanics. Today, there is no longer a dominant interpretation of quantum theory, so it is important to re-evaluate the historical sources and keep the debate open. This book contains a complete translation of the original proceedings, with essays on the three main interpretations presented, and a detailed analysis of the lectures and discussions in the light of current research. This book will be of interest to graduate students and researchers in physics and in the history and philosophy of quantum theory.

Part I. Perspectives on the 1927 Solvay Conference: 1. Historical introduction; 2. De Broglie's pilot-wave theory; 3. From matrix mechanics to quantum mechanics; 4. Schrödinger's wave mechanics; Part II. Quantum Foundations and the 1927 Solvay Conference: 5. Quantum theory and the measurement problem; 6. Interference, superposition, and wave packet collapse; 7. Locality and incompleteness; 8. Time, determinism, and the spacetime framework; 9. Guiding fields in 3-space; 10. Scattering and measurement in de Broglie's pilot-wave theory; 11. Pilot-wave theory in retrospect; 12. Beyond the Bohr-Einstein debate; Part III. The Proceedings of the 1927 Solvay Conference: The intensity of X-ray reflection; Disagreements between experiment and the electromagnetic theory of radiation; The new dynamics of quanta; Quantum mechanics; Wave mechanics; General discussion; Appendix; References; Index.

Guido Bacciagaluppi is a Senior Research Fellow at the Centre for Time, University of Sydney. His research interests lie mainly in the philosophy of physics. He has contributed significantly to the development and critique of modal interpretations of quantum mechanics, and he has since worked widely in various approaches to the foundations of quantum theory, as well as in the philosophy of probability and time and in the history of quantum mechanics.
Antony Valentini is a Research Associate in the Theoretical Physics Group, Imperial College London. He proposed that the universe began with a non-quantum distribution of hidden variables, which later relaxed to the quantum equilibrium state we see today. He has pioneered the development of new physics of quantum nonequilibrium, de Broglie-Bohm theory, and hidden-variables theories generally, and has explored its possible role in cosmology, black holes, and information theory. He also works in the history and philosophy of modern physics.