On Time, Causation and Explanation in the Causally Symmetric Bohmian Model of Quantum Mechanics

Abstract

Quantum mechanics portrays the universe as involving non-local influences that are difficult to reconcile with relativity theory. By postulating backward causation, retro-causal interpretations of quantum mechanics could circumvent such influences and, accordingly, increase the prospects of reconciling these theories. The postulation of backward causation poses various challenges for retro-causal interpretations of quantum mechanics and for the existing conceptual frameworks for analyzing counterfactual dependence, causation and causal explanation, which are important for studying these interpretations. In this chapter, we consider the nature of time, causation and explanation in a local, deterministic retro-causal interpretation of quantum mechanics that is inspired by Bohmian mechanics. This interpretation, the ‘causally symmetric Bohmian model’, offers a deterministic, local ‘hidden-variables’ model of the Einstein-Podolsky-Rosen/Bohm experiment that presents a new challenge for Reichenbach ’s principle of the common cause. In this model, the common cause – the ‘complete’ state of the particles at the emission from the source – screens off the correlation between its effects – the distant measurement outcomes – but nevertheless fails to explain it.