Maxwell - Electricity & Magnetism
Maxwell’s equations show that electric and magnetic forces travel at a definite predicted speed -- NOT instantaneous “action at a distance”
Travel as electromagnetic waves - recall that a changing electric field generates a magnetic field and vice versa
Travel in free space (vacuum) at a speed determined by the constants in Coulomb’s law and Faraday’s law
Using values for the constants measured in the laboratory, speed predicted to be equal to the speed of light! c = 3.0 x 108 m/s