  The classical dynamics in stationary potentials that are random both in space
and time is studied. It can be intuitively understood with the help of Chirikov
resonances that are central in the theory of Chaos, and explored quantitatively
in the framework of the Fokker-Planck equation. In particular, a simple
expression for the diffusion coefficient was obtained in terms of the average
power density of the potential. The resulting anomalous diffusion in velocity
is classified into universality classes. The general theory was applied and
numerically tested for specific examples relevant for optics and atom optics.
