  We perform numerical measurements of the moments of the position of a tracer
particle in a two-dimensional periodic billiard model (Lorentz gas) with
infinite corridors. This model is known to exhibit a weak form of
super-diffusion, in the sense that there is a logarithmic correction to the
linear growth in time of the mean-squared displacement. We show numerically
that this expected asymptotic behavior is easily overwhelmed by the subleading
linear growth throughout the time-range accessible to numerical simulations. We
compare our simulations to the known analytical results for the variance of the
anomalously-rescaled limiting normal distributions.
