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:
-
Ravens
-
Crested caracaras
-
World Space Week begins
-
Spotted Lake emerges
-
Plate-billed mountain toucan with orchids, Ecuador
-
Long-eared owl in the Czech Republic
-
World Book Day
-
Medieval towers in Mestia, Upper Svaneti, Georgia
-
The Crown Jewel of the North Atlantic
-
Tesla, the visionary
-
Happy Panda Day!
-
The otherworldly red river
-
Rapa Valley in Sarek National Park, Sweden
-
Weaverbird nests at Kenya’s Samburu National Reserve
-
Celebrating Bike to Work Week, May 14-18
-
International Day of Human Space Flight
-
Light show in the forest
-
World Book Day
-
Glendurgan Garden hedge maze is 186 years old
-
Humpbacks return to the Inside Passage
-
The Alhambra in Granada, Spain
-
Thorrablot: The Icelandic midwinter festival
-
Travel Sunday: On the Ganges in Varanasi, India
-
Virginia Creeper Trail, Damascus, Virginia
-
The Canary Islands, Spain
-
Mid-Autumn Festival
-
Let s get lost
-
Third Thai-Lao Friendship Bridge connecting Laos and Thailand
-
Hnausapollur crater lake, Fjallabak Nature Reserve, Iceland
-
Summer solstice
Bing Wallpaper Gallery

