22.1. Galilean Relativity http://www.ck12.org
form of electric and magnetic phenomena). Were Maxwell’s equations incorrectly stated, perhaps? Or, maybe,
Galilean relativity did not apply to light?
Resolving the Paradox
Many explanations were proposed to explain the null result of the Michelson-Morley experiment. Two prominent
late 19th century physicists, Hendrick Antoon Lorentz (1853-1928) and G.F. Fitzgerald (1851-1901),indepen-
dently suggested that the arm of the interferometer, when parallel to the motion through the ether, was shortened
(contracted) by an amount just enough to account for the smaller round trip time of the light. Lorentz suggested
that the forces between the molecules of matter, being electrical, would perhaps explain the effect. No evidence
supported that conjecture, however. The physics community was flabbergasted.
Finally, in 1905, Albert Einstein’s famous paper containing what’s now known as the special theory of relativity
was published, giving a much better explanation for the Michelson-Morley experiment. The mathematics which
Lorentz (and Fitzgerald) developed in order to explain the apparent length contraction was the same developed by
Einstein in his special theory and is now called the Lorentz transformation. What Lorentz (and Einstein) transformed
was Galilean relativity (the Galilean equations of motion), in order that electromagnetic phenomena be described
properly.