  We discuss the existence of an acceleration scale in galaxies and galaxy
clusters. The presence of the same acceleration scale found at very different
scales and in very different astrophysical objects strongly supports the
existence of a fundamental acceleration scale governing the observed
gravitational physics. We also comment on the implication of such a fundamental
acceleration scale on the problem of dark matter. We discuss the relevance of
the fundamental acceleration for the nature of dark matter as well as for
structure formation to be explored in future numerical simulations.
