Abstract ‘Origins of Pilot-Wave Theory’ delves into the historical origins of pilot-wave theory and clarifies many of the misunderstandings surrounding it. We begin with an account of Louis de Broglie’s work in the 1920s, including his lecture at the famous but widely misunderstood 1927 Solvay conference. We show how this troubled theory has been repeatedly dismissed and frequently misrepresented. We describe the rise of the notorious measurement problem, the widespread confusion about the nature of probability in pilot-wave theory, as well as attempts to associate the theory with mysticism and the paranormal. The chapter ends with a careful assessment of the scientific evidence for nonlocality (action at a distance), in the form of measured violations of Bell’s inequality.
Abstract ‘Origins of Pilot-Wave Theory’ delves into the historical origins of pilot-wave theory and clarifies many of the misunderstandings surrounding it. We begin with an account of Louis de Broglie’s work in the 1920s, including his lecture at the famous but widely misunderstood 1927 Solvay conference. We show how this troubled theory has been repeatedly dismissed and frequently misrepresented. We describe the rise of the notorious measurement problem, the widespread confusion about the nature of probability in pilot-wave theory, as well as attempts to associate the theory with mysticism and the paranormal. The chapter ends with a careful assessment of the scientific evidence for nonlocality (action at a distance), in the form of measured violations of Bell’s inequality.
Abstract The pilot-wave theory of de Broglie and Bohm has a special place in the history of contemporary physics, being it the very first alternative formulation of quantum mechanics. As is well-known, such a framework established itself as a leading interpretation of the quantum formalism in virtue of the solutions provided to the major technical and conceptual challenges affecting the orthodox view. The de Broglie-Bohm theory in fact not only solves the famous measurement problem, one of the most cogent issues faced by standard quantum mechanics, but also it clarifies the formal structure of the latter theory as a consequence of a consistent set of principles and an precise, unambiguous ontology. This volume aims to provide the reader with a discussion of the pilot-wave perspective which is as informative, comprehensive and accessible as possible, while at the same time clarifying confusions and misunderstandings that are unfortunately still common in literature despite the long history of this theoretical framework. The book features chapters about the various perspectives on the pilot-wave theory, its extensions to relativity and quantum field theory, and its experimental applications to various branches of physics, as for instance quantum electrodynamics, quantum chemistry, and quantum engineering. Moreover, the volume includes essays on the history and philosophy of de Broglie-Bohm theory in order to delineate its developments and the vicissitudes of its pioneers, as well as to understand the scientific image of the universe it provides.
At the 1927 Solvay conference, three different theories of quantum mechanics were presented; however, the physicists present failed to reach a consensus. Today, many fundamental questions about quantum physics remain unanswered. One of the theories presented at the conference was Louis de Broglie's pilot-wave dynamics. This work was subsequently neglected in historical accounts; however, recent studies of de Broglie's original idea have rediscovered a powerful and original theory. In de Broglie's theory, quantum theory emerges as a special subset of a wider physics, which allows non-local signals and violation of the uncertainty principle. Experimental evidence for this new physics might be found in the cosmological-microwave-background anisotropies and with the detection of relic particles with exotic new properties predicted by the theory.
At the 1927 Solvay conference, three different theories of quantum mechanics were presented; however, the physicists present failed to reach a consensus. Today, many fundamental questions about quantum physics remain unanswered. One of the theories presented at the conference was Louis de Broglie's pilot-wave dynamics. This work was subsequently neglected in historical accounts; however, recent studies of de Broglie's original idea have rediscovered a powerful and original theory. In de Broglie's theory, quantum theory emerges as a special subset of a wider physics, which allows non-local signals and violation of the uncertainty principle. Experimental evidence for this new physics might be found in the cosmological-microwave-background anisotropies and with the detection of relic particles with exotic new properties predicted by the theory.
Abstract ‘Seeing the Impossible’ delves into the details of pilot-wave theory and of how it can account for the mysteries of quantum physics. We begin with the iconic two-slit experiment and show how it can be understood in terms of particles moving through one hole or the other (despite widespread claims to the contrary). We give a clear explanation for so-called quantum randomness in terms of unknown ‘initial conditions’. We also show how Born’s usual formula, for quantum probability, can emerge from the peculiar particle motions predicted by the laws of pilot-wave theory. The chapter ends with a detailed discussion of how pilot-wave theory explains nonlocality, or spooky action at a distance, between widely separated particles.
As we discussed in Section 2.4, in his Solvay lecture of 1927 de Broglie presented the pilot-wave dynamics of a non-relativistic many-body system, and outlined some simple applications of his ‘new dynamics of quanta’ (to interference, diffraction and atomic transitions). Further, as we saw in Section 10.2, contrary to a widespread misunderstanding, in the general discussion de Broglie's reply to Pauli's objection contained the essential points needed to treat inelastic scattering (even if Fermi's misleading optical analogy confused matters): in particular, de Broglie correctly indicated how definite quantum outcomes in scattering processes arise from a separation of wave packets in configuration space. We also saw in Section 10.4 that de Broglie was unable to reply to a query from Kramers concerning the recoil of a single photon on a mirror: to do so, he would have had to introduce a joint wave function for the photon and the mirror. De Broglie's theory was revived by Bohm 25 years later (Bohm 1952a,b) (though with the dynamics written in terms of a law for acceleration instead of a law for velocity). Bohm's truly new and very important contribution was a pilot-wave account of the general quantum theory of measurement, with macroscopic equipment (pointers, etc.) treated as part of the quantum system. In effect, in 1952, Bohm provided a detailed derivation of quantum phenomenology from de Broglie's dynamics of 1927 (albeit with the dynamical equations written differently).
Abstract Objections to pilot-wave theory frequently come in three mutually-contradictory categories: that the theory is too bizarrely different from ordinary physics, that the theory is not radically different enough, and that the physics of pilot-wave theory is after all just the same as quantum physics. After a brief review of pilot-wave theory, we critically evaluate these objections. We show how the radical nature of pilot-wave theory is often misunderstood or overlooked. We highlight the novelty of its dynamics, and clarify its implications for our understanding of measurement, as well as discussing the status of Lorentz invariance, conservation laws, and the Born rule. We examine Einstein’s early work on pilot-wave theory and argue that he turned away from it for reasons which are no longer compelling. We urge that the theory be understood on its own terms, as a generalised nonequilibrium theory empirically distinct from quantum mechanics, with all its potentially revolutionary implications