Plane wave solutions have unphysical properties. They are of infinite
length and the wave fronts have infinite area. Everywhere in an infinite plane
normal to the direction of propagation
E(t) and B(t) are the same. This is an attempt to
visualize a sinusoidal plane wave propagating along the z-direction,
i.e. E only varies along the z-direction, and not along any direction in
the xy plane.