  The capillary levelling of cylindrical holes in viscous polystyrene films was
studied using atomic force microscopy as well as quantitative analytical
scaling arguments based on thin film theory and self-similarity. The relaxation
of the holes was shown to consist of two different time regimes: an early
regime where opposing sides of the hole do not interact, and a late regime
where the hole is filling up. For the latter, the self-similar asymptotic
profile was derived analytically and shown to be in excellent agreement with
experimental data. Finally, a binary system of two holes in close proximity was
investigated where the individual holes fill up at early times and coalesce at
longer times.
