If you needed to illustrate the idea of nineteenth-century America as a land of opportunity, you could hardly improve on the life of Albert Michelson.
Born in 1852 on the German–Polish border to a family of poor Jewish merchants,
he came to the United States with his family as an infant and grew up in a mining camp in California’s gold rush country,
where his father ran a dry goods business.
Too poor to pay for college, he traveled to Washington, D.C., and took to loitering by the front door of the White House
so that he could fall in beside President Ulysses S. Grant when the President emerged for his daily constitutional.
(It was clearly a more innocent age.)
In the course of these walks,
Michelson so ingratiated himself to the President that Grant agreed to secure for him a free place at the U.S. Naval Academy.
It was there that Michelson learned his physics.
Ten years later, by now a professor at the Case School in Cleveland,
Michelson became interested in trying to measure something called the ether drift—a kind of head wind produced by moving objects as they plowed through space.
One of the predictions of Newtonian physics was that the speed of light as it pushed through the ether should vary with respect to an observer
depending on whether the observer was moving toward the source of light or away from it, but no one had figured out a way to measure this.
It occurred to Michelson that for half the year the Earth is traveling toward the Sun and for half the year it is moving away from it,
and he reasoned that if you took careful enough measurements at opposite seasons and compared light’s travel time between the two, you would have your answer.
注：据考，文中“Ten years later...”音频中误读作“Two years later...”。