  The interplay between acceleration and radiation harbors remarkable and
surprising consequences. One of the most striking is that the Larmor radiation
emitted by a charge can be seen as a consequence of the Unruh thermal bath.
Indeed, this connection between the Unruh effect and classical bremsstrahlung
was used recently to propose an experiment to confirm (as directly as possible)
the existence of the Unruh thermal bath. This situation may sound puzzling in
two ways: first, because the Unruh effect is a strictly quantum effect while
Larmor radiation is a classical one, and second, because of the crucial role
played by zero-frequency Rindler photons in this context. In this paper we
settle these two issues by showing how the quantum evolution leads naturally to
all relevant aspects of Larmor radiation and, especially, how the corresponding
classical radiation is entirely built from such zero-Rindler-energy modes.
