Assertion: sound wave's medium | /r/HasProperty | anisotropic
Facets:
Source sentences:
text: If the medium is anisotropic, the wave vector in general points in directions other than that of the wave propagation.
text: The condition for the wave vector to point in the same direction in which the wave propagates is that the wave has to be homogeneous, which isn't necessarily satisfied when the medium is anisotropic.