Foucault pendulum

American  

noun

Physics.

1. a pendulum that demonstrates the rotation of the earth by exhibiting an apparent change in its plane of oscillation.

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Foucault pendulum Scientific  

1. A pendulum suspended from a long wire, set into motion, and sustained in motion over long periods. Due to the axial rotation of the earth, the plane of motion of the pendulum shifts at a rate and direction dependent on its latitude, clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere. At the poles the plane rotates once per day, while at the equator it does not rotate at all.

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Etymology

Origin of Foucault pendulum

First recorded in 1850–55; named after J.B.L. Foucault

Example Sentences

The Foucault pendulum is a way to demonstrate that Earth is turning.

From Textbooks • Oct. 13, 2016

Last week, in the idle elevator shaft, installed and ready to operate was a 120-foot Foucault pendulum, the longest in existence.

From Time Magazine Archive

The first thing I noticed was that the duct tape had come off my Foucault pendulum.

From "Schooled" by Gordon Korman

I stepped out of the house, careful not to disturb my science project—the Foucault pendulum suspended from the porch roof.

From "Schooled" by Gordon Korman

From February 26th to April 20th, Professor Rumi made observations on the after-shocks by means of the Foucault pendulum erected at Genoa for demonstrating the rotation of the earth.

From A Study of Recent Earthquakes by Davison, Charles