Just How Radical is Hyperplane Dependence

Recently Tim Maudlin of Rutgers University has published a book, entitled Quantum Nonlocality and Relativity (1994), in which some of the peculiar twists taken by the quantum measurement problem in the relativistic domain are discussed in depth, albeit at a rather non-technical level. In the chapter entitled “Points of View” he considers, as one of several approaches, my arguments concerning hyperplane dependent state vector reduction (Fleming 1985, 1989). While he does not embrace my view, nor that of any other author he discusses, his account is fair and I welcome this opportunity to respond to some of his observations. In particular, while clearly understanding the nature of the requirement of Lorentz covariance in a realist account of state reduction, and fully acknowledging that hyperplane dependent reduction satisfies that requirement, Maudlin is troubled by what he perceives as the proliferation of ontology thereby entailed. This prompts his comment, “We are here faced with a radically new ontological conception of the world..” Hence my title.