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:
-
Gunnerside, Yorkshire Dales National Park, England
-
Rock formations at Sedona, Arizona
-
Diamond Beach, Iceland
-
Looking for peace on the precipice
-
Adorably evolutionary sea sheep
-
Harvest time in the Palouse
-
Even nature needs a backup plan…
-
Totally Thames Festival, London
-
International Polar Bear Day
-
Jan van Eyckplein in Bruges, Belgium
-
Albuquerque International Balloon Fiesta
-
Northern coast of Colombia
-
Going with the floe
-
Social climbing
-
Celebrating whales—and a whale of a tale
-
Manatee Appreciation Day
-
World Wildlife Day
-
Of moose and Maine
-
Darwin Day
-
Whooper swans, Kotoku Pond, Japan
-
Noctilucent clouds
-
Where do those colors come from?
-
Wildebeests in Maasai Mara, Kenya
-
European Day of Parks
-
Cheers! It’s National Wine Day
-
Making it work—in Norway
-
Looking back on 150 years of rail travel
-
2024 Toronto International Film Festival
-
Short-eared owl
-
Alaska National Interest Lands Conservation Act marks 42 years
Bing Wallpaper Gallery

