  According to the classical Einstein-Maxwell theory of gravity and
electromagnetism, a light-wave traveling in empty space-time is accompanied by
a gravitational field of the pp-type. Therefore point masses are scattered by a
light wave, even if they carry no electric or magnetic charge, or dipole
moment. In this paper I present the explicit form of the metric and curvature
for both circularly and linearly polarized light, and discuss the geodesic
motion of test masses. This is followed by a discussion of classical scattering
of point particles by the gravitational field associated with a circularly
polarized electromagnetic block wave. A generalization to a quantum theory of
particles in the background of these classical wave fields is presented in
terms of the covariant Klein-Gordon equation. I derive the energy spectrum of
quantum particles in the specific case of the circularly polarized block wave.
Finally, a few general remarks on the extension to a quantum light wave are
presented.
