Foucault's pendulum Google doodle
Google changed its doodle to honor Leon Foucault, inventor of the famed pendulum that demonstrated Earth's rotation. (Google / September 18, 2013)
Happy birthday, Jean Bernard Leon Foucault, and thanks for the pendulum.
The French physicist and inventor was born in Paris on this day in 1819.
It may be hard to fathom, but the idea of Earth rotating on its axis, first proposed in the 6th century, took many centuries to gain favor, and many more to be demonstrated. The Copernican theory of celestial motions was well accepted by science by the time Foucault was born. It elegantly explained the apparent "rise" and "set" of the sun, but it was difficult to "prove" by experiment.