Wigner's friend within a realist toy model.

Wigner's gedankenexperiment is often taken as requiring a reassessment of the notion of objective reality. In this brief note however we present a classical toy model in which (i) The relevant quantum mechanical predictions of Wigner's thought experiment are reproduced (ii) Every system is in a well-defined state at all times. The toy model shows how puzzles such as Wigner's friend's experience of being in a superposition, conflicts between different agents' descriptions of the experiment, the positioning of the Heisenberg's cut and the apparent lack of objectivity of measurement outcomes can be explained within a classical model where there exists an objective state of affairs about every physical system at all times. Within the model, the debate surrounding Wigner's friend thought experiment and its resolution have striking similarities with arguments concerning the nature of the second law of thermodynamics. The same conclusion however does not straightforwardly apply to more recent extensions of the gedankenexperiment featuring multiple encapsulated observers.