My Research to Date 

My post-dissertation work has consisted of a set of connected investigations centred around the interpretation of quantum mechanics.  This issue concerns the question of what, if anything, we can infer about the way the world is from the unquestioned empirical success of quantum mechanics.  There are a number of disparate approaches to this issue, and one attitude that has been taken is that a choice between interpretative programmes is ultimately a matter of taste.  I believe that this attitude stems from too narrow a construal of the way in which empirical considerations can bear on physical theories; there seems to be a prevailing attitude—sometimes explicit, sometimes not—that all options not conclusively ruled out by experiment are on a par evidentially. 

One way that evidential concerns can be brought into play is via investigations of compatibility with relativity theory.  The fact of quantum nonlocality has been thought by some to show that no interpretation of quantum mechanics can be compatible with relativity theory; I have argued, in two papers, “On Peaceful Coexistence,” and “Relativistic Quantum Becoming,” that such a conclusion is premature. 

My paper, “On Some Early Objections to Bohm’s Theory,” is also addressed, in part, to the notion that there are no rational reasons to prefer one interpretation of quantum mechanics over another.  There is a prevalent myth that Bohm’s hidden-variables interpretation was either ignored by the physics community at the time of its proposal or met only with ridicule; this myth tends to reinforce the notion that there can be no cogent argumentation comparing interpretational programmes.  My motives in writing this paper were partly to set the historical record straight, but also in part to consider the bearing of the arguments raised at the time on current debates.  It turns out that certain aspects of these arguments have only recently been given precise form; my Physics Letters A paper is an extension of some recent work relevant to these 50-year-old debates. 

The Foundations of Physics paper shows how the violation of relativity exhibited by the Bohm theory must also be shared by a wide class of interpretations of quantum mechanics.  

My work on confirmation theory, consisting of the joint PSA paper with Harper, and “A Bayesian Account of the Virtue of Unification,” may seem, prima facie, to be distantly connected with the other work.  However, I believe that much of the discussion of the foundations of quantum mechanics is hampered by too narrow a construal of the bearing of empirical considerations on matters of theory, and it is important for such discussions to get clear about the nature of the relation of empirical evidence to theory.  For example, on the Bayesian approach to scientific inference, it is not possible to hold that all theories compatible with a body of evidence are equally well supported by it, and in my paper, “A Bayesian Account of the Virtue of Unification,” I demonstrate that what has often been regarded as a merely aesthetic virtue of a theory—namely, the ability of the theory to unify disparate phenomena—must, on a Bayesian approach to scientific inference, be regarded as contributing to the evidential support lent to the theory by the phenomena.   The collaboration with Harper also concerns the extent to which a virtue often regarded as aesthetic, namely, simplicity, can be regarded as having epistemic import. 

I am currently working on a collaborative project with Antony Valentini of the Perimeter Institute for Theoretical Physics, investigating the ways in which Lucien Hardy’s axioms for quantum theory break down in the context of de Broglie-Bohm pilot-wave theory with non-equilibrium distributions of particle positions.  It is hoped that this investigation will yield insight into the physical significance of these axioms.

I am also engaged in a collaborative project with William L. Harper, tentatively entitled “Why Bayesians should countenance objective chance,” addressed at those Bayesians who hold that all probabilities are epistemic.  This paper, or a sequel, will argue that physicists who approach quantum-mechanics from the point of view of information theory should nevertheless regarded quantum probabilities as objective chances rather than subjective degrees of belief. 

A third project, near completion,  is a sequel to my Philosophy of Science paper, “A Bayesian Account of the Virtue of Unification,” which will be more accessible to a wide philosophical audience, and also compare my views to what other philosophers have said about unification.