  If electromagnetic parameters of a medium vary in time, quantum light waves
traveling in it become nonstatic. A recent report shows that such nonstatic
waves can also appear even when the environment is static where the parameters
of the medium do not vary. In this work, the properties of nonstatic waves in a
static environment are investigated from their $p$-space analysis, focusing on
the interrelation between the $q$- and $p$-space nonstatic waves. The
probability densities in $p$-space (as well as in $q$-space) for both the
nostatic Fock and Gaussian states evolve in a periodic manner, i.e., they
constitute belly and node in turn successively as time goes by. If we neglect
the displacement of waves, the $q$- and $p$-space wave phases are opposite each
other. Since the intensity of the wave in each space is relatively large
whenever the wave forms a belly, such a phase difference indicates that
periodical intensity exchange between the $q$- and $p$-component waves takes
place through their nonstatic evolutions. This is the novel reciprocal optical
phenomenon arisen on account of the wave nonstaticity.
