If you know that the earth rotates (And if you didn’t, surprise!) you have French physicist Léon Foucault to thank.
While he wasn’t the first to float the theory, his 1851 demonstration on the Foucault pendulum was the first easy-to-see proof that the earth was not, in fact, unmoving. This demonstration involved suspending a 67-metre, 28kg pendulum suspended from the Panthéon’s dome in Paris. “The plane of its motion, with respect to the earth, rotated slowly clockwise. The experiment sparked a pendulum-mania across Europe and the United States, and crowds were attracted to observe so-called ‘Foucault pendulums’ in major cities on both sides of the Atlantic,” according to The Guardian.
A recreation of his famous pendulum – along with buttons to manipulate the movement – is Google’s Doodle today, on what would have been Foucault’s 194th birthday. Clicking on the search icon takes you to info about Foucault; on the homepage, users can change both the speed and the angles of the ball to see how it affects rotation.
Just be sure to keep it away from Miley Cyrus.