Electromagnetic Waves

Maxwell’s equations may be manipulated to produce three-dimensional wave equations for electric and magnetic fields. The solutions to these equations are called electromagnetic waves. They have the following properties:

Electromagnetic waves travel through vacuum with the speed of light:

Electromagnetic waves are transverse waves with E ^ B ^ direction of propagation.
E and B oscillate in phase, with E/B = c at all times for which the fields are nonzero.
Electromagnetic waves carry energy in the direction of propagation. The Poynting vector S has magnitude equal to the rate of energy flow through a unit area and direction equal to the direction of propagation:

Electromagnetic waves carry momentum and hence can exert a radiation pressure. If the surface is perfectly absorbing, P = S/c. Reflective surfaces give P = 2S/c.