  A renewed analysis of the H.E. Ives and G.R. Stilwell's experiment on moving
hydrogen canal rays (J. Opt. Soc. Am., 1938, v.28, 215) concludes that the
spectral emission of a moving atom exhibits always a redshift which informs not
the direction of the atom's motion. The conclusion is also evident from a
simple energy relation: atomic spectral radiation is emitted as an orbiting
electron consumes a portion of its internal energy on transiting to a
lower-energy state which however has in a moving atom an additional energy
gain; this results in a redshift in the emission frequency. Based on auxiliary
experimental information and a scheme for de Broglie particle formation, we
give a vigorous elucidation of the mechanism for deceleration radiation of
atomic electron; the corresponding prediction of the redshift is in complete
agreement with the Ives and Stilwell's experimental formula.
