Bohmian Mechanics and Its Ontological Commitments

Abstract

One of the putative lessons from quantum mechanics is that the mathematical structure of that theory and empirical evidence demand that we accept a view of our physical world in which fundamental physical processes at the microlevel are irreducibly and ineliminably indeterministic and even that there cannot exist an objective, observer-independent reality (or “truth of the matter”). This is certainly a world view that is consonant with the standard, or “Copenhagen”, interpretation of quantum mechanics, often associated with some of the founding fathers of quantum theory, such as Niels Bohr, Max Born and Werner Heisenberg. I first substantiate this representation of the Copenhagen interpretation by examining typical claims made by these founders and succinctly summarize those positions. I then argue that this common acceptance of the necessity of indeterminism is unfounded, since there exists an alternative version of quantum mechanics, one due to David Bohm, that can be in principle empirically indistinguishable from standard quantum mechanics. Moreover, in Bohmian mechanics (BM), fundamental physical processes at the microlevel are irreducibly and ineliminably deterministic and there exists an objective, observer-independent reality. While this alternative formulation of quantum mechanics does allow one to have an ontology that is much closer to that of classical physics than is usually associated with quantum phenomena, it does at the same time raise foundational questions about the status of the special theory of relativity and about the ontology of spacetime.