Statistical mechanics Microscopic chaos from brownian motion?

Gaspard et al. have analysed a time series of the positions of a brownian particle in a liquid, and claimed that it provides empirical evidence for microscopic chaos on a molecular scale. An accompanying comment emphasized the fundamental nature of the experiment. Here we show that virtually identical results can be obtained by analysing a corresponding numerical time series of a particle in a manifestly microscopically non-chaotic system.