Question

how is light propogated

Answer 1

The oscillations of the two fields are perpendicular to each other and perpendicular to the direction of energy and wave propagation, forming a transverse wave. The wavefront of electromagnetic waves emitted from a point source (such as a light bulb) is a sphere.

Answer 2

Still the fields are there! Therefore, just as a matter wave (which is nothing but a particle), light waves, i.e. waves in the electromagnetic field, canpropagate through such a "perfect vacuum".