Electromagnetic Field

A description of the field from a current which changes in time is much more complicated, but is calculable owing to James Clerk Maxwell (1831–1879). His equations, which have unified the laws of electricity and magnetism, are called Maxwell's equations. They are differential equations which completely describe the combined effects of electricity and magnetism, and are considered to be one of the crowning achievements of the nineteenth century. Maxwell's formulation of the theory of electromagnetic radiation allows us to understand the entire electromagnetic spectrum, from radio waves through visible light to gamma rays.