Science: Atomic Clocks

The famed Michelson-Morley experiment of 1887, in which perpendicular beams of light were raced against each other, seemed to show that a light-carrying ether pervading all space did not exist. Fitzgerald, Larmor and Lorentz shored up the collapsing ether-concept by showing—theoretically—that a moving body must contract slightly in the direction of motion, that a moving clock would therefore slow down. Though imperceptible except at speeds approaching light's velocity (186,000 mi. per sec.), these changes would affect a Michelson-Morley apparatus just enough to cancel any possible observation of the ether-drift—by altering the timing...