Historical Background

Maxwell's Equations, in the late 19th century, did for E&M what Newton's Laws had done for Mechanics two centuries earlier.

Maxwell's Equations predicted a wave in E & M fields with a speed of

v = 3 x 108 m/s,

surprisingly close to the measured speed of light of

c = 3 x 108 m/s.

Remember A A Michelson, and his measurements of the speed of light, starting in 1877,

Michelson invented the interferometer to measure the speed of light in different directions, looking for the luminiferous ether!

Look back on our moving observers A and B,

What do they observe for the speed of light?

Experimentally, both observers find the same value for the speed of light !

How can this be?

Galilean Relativity

Einsteinean Relativity and SpaceTime Coordinates

Return to Ch 27, Special Relativity

(c) Doug Davis, 2002; all rights reserved