  Thermal scalar radiation in two spacetime dimensions is treated within
relativistic classical physics. Part I involves an inertial frame where are
given the analogues both of Boltzmann's derivation of the Stefan-Boltzmann law
and also Wien's derivation of the displacement theorem using the scaling of
relativitic radiation theory. Next the spectrum of classical scalar zero-point
radiation in an inertial frame is derived both from scale invariance and from
Lorentz invariance. Part II involves the behavior of thermal radiation in a
coordinate frame undergoing (relativistic) constant acceleration, a Rindler
frame. The radiation normal modes in a Rindler frame are obtained. The
classical zero-point radiation of inertial frames is transformed over to the
coordinates of a Rindler frame. Although for zero-point radiation the two-field
correlation function at different spatial points at a single time is the same
between inertial and Rindler frames, the correlation function at two different
times at a single Rindler spatial coordinate is different, and has a natural
extension to non-zero temperature. The thermal spectrum in the Rindler frame is
then transferred back to an inertial frame, giving the familar Planck spectrum.
