Abstract The old guard reacted predictably to Bohm’s theory, but were obliged to concede its logical consistency. Oppenheimer denounced it as ‘juvenile deviationism’. With the help of his communist assistant, Jean-Pierre Vigier, de Broglie re-embraced the pilot wave theory he had abandoned in 1927. Pauli claimed that de Broglie had relapsed to his ‘shadow physics beer-idea wish dreams’ under Bohm’s ‘devilish influence’. The old guard rallied in the face of this French recidivism. Bohm and Vigier argued that the wave field could be modelled as a fluid and a particle as an inhomogeneity in the fluid, subject to many small random fluctuations. Owing to these vicissitudes, any arbitrary statistical distribution of inhomogeneities will tend towards the value dictated by the Born rule. Few were persuaded. The squabbling between Einstein and Born continued as the old guard began to fall, and as Bohm left Brazil first for Israel, and then England.
Abstract The old guard reacted predictably to Bohm’s theory, but were obliged to concede its logical consistency. Oppenheimer denounced it as ‘juvenile deviationism’. With the help of his communist assistant, Jean-Pierre Vigier, de Broglie re-embraced the pilot wave theory he had abandoned in 1927. Pauli claimed that de Broglie had relapsed to his ‘shadow physics beer-idea wish dreams’ under Bohm’s ‘devilish influence’. The old guard rallied in the face of this French recidivism. Bohm and Vigier argued that the wave field could be modelled as a fluid and a particle as an inhomogeneity in the fluid, subject to many small random fluctuations. Owing to these vicissitudes, any arbitrary statistical distribution of inhomogeneities will tend towards the value dictated by the Born rule. Few were persuaded. The squabbling between Einstein and Born continued as the old guard began to fall, and as Bohm left Brazil first for Israel, and then England.
Abstract When Oppenheimer was drawn to Los Alamos, his student David Bohm stepped in to co-present his Berkeley lectures on quantum mechanics. The effort led to a textbook, which Bohm published in 1951. Although inclined towards Copenhagen teachings, he remained enough of a Marxist to explore the possibility that the radical probabilities of the theory might be removed using hidden variables. The book included a detailed analysis of the EPR experiment, cast in a much more accessible form. A subsequent encounter with Einstein at Princeton led him to become interested in whether a deterministic extension of quantum theory could be found. He rediscovered a version of the mathematically equivalent but deterministic pilot wave theory. Its hidden variables were obliged to be non-local, which caused Bohm no discomfort. But Einstein did not like it, calling it ‘too cheap’. Driven from McCarthyite America, Bohm argued his case from exile in Brazil.
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.
Abstract David Bohm published his “Suggested Interpretation of Quantum Theory in Terms of Hidden Variables” some twenty five years after Louis de Broglie first presented his similar Pilot Wave theory of quantum mechanics. In the following 30 years what became known as the de Broglie–Bohm approach to quantum theory was to a large extent ignored within the physics community. Even David Bohm himself became somewhat disillusioned with the lack of impact of his interpretation of quantum theory and he directed his interest elsewhere. But some 27 years after Bohm had published his interpretation of quantum theory, interest was rekindled in part by new, detailed calculations that demonstrated clearly and graphically, exactly how his interpretation explained quantum phenomena in terms of well defined individual particle trajectories. These computations encompassed two-slit interference, quantum tunnelling, neutron interferometry, Wheeler’s delayed choice experiment, orbital and intrinsic angular momentum, quantum measurement and Einstein–Podolsky–Rosen nonlocal correlations for orbital angular momentum, intrinsic angular momentum and correlated particle interferometry. Since then, the acceptance of the validity of de Broglie–Bohm theory has steadily grown, as has the interest in the consequences of the approach. For my contribution to the current celebratory volume I was asked to provide a personal review specifically of this novel work within its historical context of the last quarter of the twentieth century.
In our approach we have combined knowledge of Old Masters (working in this field before the year 1905), New Masters (working in this field after the year 1905) and Dissidents under the guidance of Louis de Broglie and David Bohm. In our model the quantum particle is represented as the Huygens-de Broglie’s particle on the helical path (full wave) guided by the Newton-Bohm entangled helical evolute (Bohmian Pilot Wave). These individual Huygens - de Broglie particles in the Young - Feynman double - slit experiment react with Wilhelm Wien’s photons that are always present inside of the apparatus (Wien’s displacement law). Wilhelm Wien’s photons form collectively the Wien filter guiding the Huygens - de Broglie particles through the double - slit barrier towards a detector (BohEmian Pilot Wave). The interplay of those events creates the observed interference pattern. In the very well-known formula describing the intensity of double-slit diffraction patterns we have newly introduced the concept curvature κ of the Huygens - de Broglie particle and thus giving a physical interpretation for the Newton - Bohm guiding wave (the Bohmian Pilot Wave): for photons κ = π/λ, for electrons κ = 2π/λ. Moreover, we have introduced into that formula the expression λmax from the Wien’s displacement law to describe geometry of the double - slit barrier. We propose to modify the value λmax by the change of the system temperature. There is a second experimental possibility - we can insert into those slits filters to remove Wien’s photons while the Huygens - de Broglie particles continue towards a detector - we should observe the particle behavior. The similar situation might occur in the Mach - Zehnder interferometer. In this case the individual Huygens - de Broglie particle reacts in the first beam splitter with the Wien photon: the Huygens - de Broglie particle goes through one path while the Wien photon goes through the second path. In the second beam splitter they interact again and create the interference pattern on one detector. We can experimentally modify the resulting interference pattern in the Mach - Zehnder interferometer - by the temperature change of the system or by inserting filters to remove Wien’s photons from one or both paths. Can it be that Nature cleverly creates those interference patterns while the Bohmian pilot wave and the BohEmian pilot wave are hidden in plain sight? We want to pass this concept into the hands of Readers of this Journal better educated in the Mathematics and Physics.
Abstract This conference was lauded by Heisenberg as, “officially, the completion of the quantum theory,” while Langevin remarked it was, “where the confusion of ideas reached its peak.” The conference was held just as the theory had reached maturity, only two years after Heisenberg’s matrix mechanics was invented. De Broglie argued for his pilot wave theory, which was shot down by Pauli using an incorrect argument and in later years was re-introduced as the de Broglie–Bohm theory. Heisenberg and Dirac debated the meaning of superposition and the “collapse” of the wave function. Bohr and Einstein engaged in their legendary debate. In the conference proceedings, we see the main contributors to the new theory attempt to come to terms with its enigmas.
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).