  Einstein held that the formalism of Quantum Mechanics (QM) entails "spooky
actions at a distance". Indeed, in the 60's Bell showed that the predictions of
QM disagree with the results of any locally causal description. Accepting
non-local descriptions while retaining causality leads to a clash with the
theory of relativity. Furthermore, the causal arrow of time by definition
contradicts time-reversal symmetry. For these reasons, some authors (Feynman
and Wheeler, Costa de Beauregard, Cramer, Price) have advocated abandoning
microscopic causality. In the present article, a simplistic but concrete
example of following this line of thought is presented, in the form of a
retro-causal toy-model which is stochastic and which provides an appealing
description of the specific quantum correlations discussed by Bell. One
concludes that Einstein's "spooky actions" may occur "in the past" rather than
"at a distance", resolving the tension between QM and relativity, and opening
unexplored possibilities for future reformulations of QM.
