Discuss the dual nature of electromagnetic waves and how they travel in a vacuum and through a medium.

Question

anonymous · Answer

Electro-magnetic wave are the addition of two perpendicular sinusoidal waves one the. Electric the other magnetic. The energy streaming through space  in the form of an EM wave is shared equally between the constituents electric and magnetic fields. 
U =Ue+Ub .. the transmission of light into a medium that is homogeneous results in repetitive scattering and rescattering. Each event introduced a phase shift into the light field that corresponds to the apparent phase shift velocity of the transmitted beam from the nominal velocity in a vacume . n=c/v called index of refraction even tho photons exist only  at speed c.