We study classical radiation and the quantum bremsstrahlung effect of
a moving point scalar source. Our classical analysis provides another
example of resolving a well-known apparent paradox, that of whether or
not a constantly accelerating source radiates. Quantum mechanically,
we show that for a scalar source with arbitrary motion the tree level
emission rate of scalar particles in the inertial frame equals the sum
of emission and absorption rates of zero-energy Rindler particles in
the Rindler frame. We then explicitly verify this result for a source
undergoing constant proper acceleration.