Bohr, Bohm and entwined paths

Niels Bohr and David Bohm had radically different visions of the reality underlying quantum mechanics. Bohr’s picture evolved into the Copenhagen interpretation and is very much part of mainstream physics. Bohm’s theory is observationally equivalent to Bohr’s and is much closer in spirit to classical physics. Bohm’s version has never become mainstream, in part because it requires that a physical particle respond to a self-generated field. How the field could be generated non-locally by the particle is not addressed by the theory. However the new model of ‘Entwined Paths’ shows that, at least in one dimension, a specific space-time geometry allows a single particle to construct the full Dirac propagator. In doing this, the model shows that the contrasting views of Bohr and Bohm may well be complementary.