In 1851, when French physicist Léon Foucault performed his pendulum experiment in Paris, he became the first to prove what many scientists of his day already suspected—that the Earth spins on an axis. He conducted his first experiments 170 years ago, in early January 1851, with a relatively small prototype in the cellar of his home. Just a month later, Foucault performed his most famous pendulum demonstration, using a 62-pound spherical weight attached to a 220-foot wire, which was hung from the dome of the Panthéon, a Parisian monument. As the pendulum swung back and forth in a fixed plane, the pointed end of the weight traced lines in a compass-like circle of sand below it. As time passed, the angle of these lines began to change, demonstrating to onlookers that the Earth itself was rotating underneath the pendulum, and by extension, everyone watching was rotating as well, spinning on the surface of the great blue marble around its axis.
Take this for a spin...
Today in History
More Desktop Wallpapers:
-
Giraffes at sunset in the Masai Mara National Reserve, Kenya
-
China s colorful terraced pools
-
International Zebra Day
-
Happy Halloween!
-
Pretty, pretty…butterfly?
-
National Take the Stairs Day
-
Chicagohenge
-
Hispanic Heritage Month
-
Nazca boobies, Wolf Island, Galápagos Islands, Ecuador
-
The Girl Scouts celebrate 110 years
-
Black History Month
-
Shark Fin Cove, California
-
Gone ‘lightseeing’ in Berlin
-
Dragons Eye, Uttakleiv Beach, Norway
-
From pirate port to nature preserve
-
A stunning sight in Mexico s wilderness
-
Listening to the sea
-
A plot was afoot
-
Crested caracaras
-
The Millennium at 20
-
Everglades National Park, Florida
-
Classical music takes center stage
-
It’s Art Deco Weekend in Miami
-
Satla marshland in Bangladesh
-
Where the bearded reedling sings
-
Easter Sunday
-
National Library Week
-
Endangered Species Day
-
Oh, to sleep under the northern lights
-
Oud-West, Amsterdam, Netherlands
Bing Wallpaper Gallery

