  I present an alternative explanation of flat rotational curves of galaxies
that does not require dark matter but rather relies on classical Newtonian
dynamics and an overlooked effect of quantum tunneling. I introduce a
rotational drag force, which arises from subatomic particle tunneling through
potential barriers caused by energy fluctuations in rotating gravitational
field, and present a model for a galactic rotational curve based on Newtonian
dynamics, rotational drag force and galactic mass-density distribution. To
support the rotational drag force hypothesis I supply the results of analytical
modeling and numerical simulation of effects of the rotational drag force on
stellar orbits and galactic morphology. The obtained results provide a clear
indication that the rotational drag force can be successfully applied to
explaining a wide variety of observational phenomena ranging from flat
rotational curves of galaxies and Tully- Fisher relation to origination of
spiral galactic arms, galactic bars, and galactic warps as well as anomalous
Pioneer 10/11 acceleration and possibly high-velocity galactic clouds.
