  The growth and dynamics of solid surfaces displays a multitude of power law
relationships, which are often associated with geometric self-similarity. In
many cases the mechanisms behind these power laws are comparatively trivial,
and require little more than dimensional analysis for their derivation. The
information of interest to surface physicists then resides in the prefactors.
This point will be illustrated by recent experimental and theoretical work on
the growth-induced roughening of thin films and step fluctuations on vicinal
surfaces. The conventional distinction between trivial and nontrivial power
laws will be critically examined in general, and specifically in the context of
persistence of step fluctuations.
