  Over the past two decades, a large number of studies addressed the topic of
crystal nucleation in suspensions of hard spheres. The shared result of all
these efforts is that, at low super-saturations, experimentally observed
nucleation rates and numerically computed ones differ by more than ten orders
of magnitude. We present precise simulation results of crystal nucleation rate
densities in the meta-stable hard sphere liquid. To compare these rate
densities to experimentally measured ones, we propose an interpretation of the
experimental data as a combination of nucleation and crystal growth processes
(rather than purely the nucleation process). This interpretation may resolve
the long standing dispute about the differing rates.
