  We argue that the effective theory for electromagnetic fields in spatially
varying meson condensations in dense nuclear and quark matter is given by the
axion electrodynamics. We show that one of the helicity states of photons there
has the nonrelativistic gapless dispersion relation $\omega \sim k^2$ at small
momentum, while the other is gapped. This "nonrelativistic photon" may also be
realized at the interface between topological and trivial insulators in
condensed matter systems.
