What can bouncing oil droplets tell us about quantum mechanics?

A recent series of experiments have demonstrated that a classical fluid mechanical system, constituted by an oil droplet bouncing on a vibrating fluid surface, can be induced to display a number of behaviours previously considered to be distinctly quantum. To explain this correspondence it has been suggested that the fluid mechanical system provides a single-particle classical model of de Broglie’s idiosyncratic ‘double solution’ pilot wave theory of quantum mechanics. In this paper we assess the epistemic function of the bouncing oil droplet experiments in relation to quantum mechanics. Our analysis is framed by a two-way comparison between these experiments and recent philosophical discussions of confirmation via analogue black hole experiments (Dardashti et al., 2015) and explanations via toy models (Reutlinger et al., 2017). We find that the bouncing oil droplets are best conceived as analogue representations of quantum phenomena, rather than analogue simulations, and, furthermore, that their epistemic value should be understood in terms of how-possibly explanation, rather than confirmation. By pointing us towards the distinction between analogue simulation and analogue representation in current scientific practice the walker experiments evidence the wider philosophical moral that the relations of ‘material surrogacy’ and ‘material representation’ are distinct