  Arguments of astronomers against equation of motion for arbitrarily shaped
particle under action of electromagnetic radiation are discussed. Each of the
arguments is commented in detail from the point of view of the required
physics. It is shown that the arguments of astronomers, including referees in
several astronomical and astrophysical journals, are unacceptable from the
physical point of view. Detail explanations should help astronomers in better
physical understanding of the equation of motion. Relativistically covariant
equation of motion for real dust particle under the action of electromagnetic
radiation is derived. The particle is neutral in charge. Equation of motion is
expressed in terms of particle's optical properties, standardly used in optics
for stationary particles.
