The causal theory revisited

Abstract

Review of Quantum Causality, by Peter J. Riggs. Springer. 2009.Ward StruyveInstitute of Theoretical Physics, Institute of PhilosophyK.U.LeuvenLeuven, BelgiumWhile standard quantum theory is empirically extremely successful, it is a measurementtheory, making predictions about possible outcomes of measurements. Since the notionof measurement is rather ambiguous, it can not be regarded as a fundamental theoryof nature. An alternative theory which is free of this problem and yet reproducesthe predictions of standard quantum theory (at least when those are unambiguous) isthe deBroglie-Bohm theory. This theory forms the subject of Riggs’ book \QuantumCausality".The book is centered around some novel elements, of which I think the most im-portant ones are: a new notion of energy, an alternative view on the nature of thewavefunction, a proposal for experimentally distinguishing the deBroglie-Bohm theoryfrom standard quantum theory and an attempt to derive the exclusion principle. I wantto critically assess these elements here.The deBroglie-Bohm theory, or Causal Theory as Riggs prefers to call it, is a theoryabout particles that follow trajectories in a deterministic way, inuenced by the wave-function. The possible trajectories x