  It is well known that an accelerated charged particle radiates away energy.
However, whether an accelerated neutral composite particle radiates away energy
is unclear. We study decoherent Larmor radiation from an accelerated neutral
composite object. We find that the neutral object's long wavelength radiation
is highly suppressed because radiation from different charges is canceled out.
However, the neutral object radiates high energy or short wavelength radiation
without any suppression. In that case, radiation from each particle can be
treated independently, and it is called the decoherent radiation. We compare a
hydrogen atom's decoherent Larmor radiation with its gravitational radiation
while the atom is in a circular orbit around a star. Gravitational radiation is
stronger than the electromagnetic radiation if the orbital radius is larger
than some critical radius. Since the decoherent radiation is related to the
object's structure, this implies that the strong equivalence principle which
states that gravitational motion does not depend on an object's constitution
has severe limitations..
