On Wednesday, Google replaced its homepage logo with an interactive Google Doodle animation of the Foucault pendulum in celebration of the 194th birthday of French physicist Leon Foucault.
The Foucault pendulum featured in the animation was a device designed by Foucault to demonstrate the Earth’s rotation. The pendulum was unveiled in 1851, where it was displayed in the Meridian of the Paris Observatory.
The interactive virtual Foucault pendulum in Wednesday’s Google Doodle demonstrates how the pendulum works through interactive sliders that simulate the effect that Earth’s rotation and the geographic location of the pendulum have on it. The original Foucault pendulum swung constantly throughout the day, with its plane swing rotating clockwise at 11 degrees per hour, making a full circle 32.7 hours.
Leon Foucault was born Sept. 18, 1819, in Paris, where he was home-schooled. While he is best-remembered for his pendulum, his other works included one of the earlier measurements of the speed of light, the discovery of eddy currents and naming the gyroscope.
Foucault died of multiple sclerosis on Feb. 11, 1868, in Paris.
Take a look at a still of the Google Doodle here and check out the full interactive animation on the Google homepage.