A Foucault pendulum, or Foucault's pendulum, named after the French physicist Leon Foucault, was conceived as an experiment to demonstrate the rotation of the Earth; its action is a result of the Coriolis effect.

It is a tall pendulum free to oscillate in any vertical plane and ideally should include some sort of motor so that it can run continuously rather than have its motion damped by air resistance.

At either the North Pole or South Pole, the plane of oscillation of a pendulum remains pointing in the same direction with respect to the fixed stars, while the Earth rotates underneath it, taking one sidereal day to complete a rotation.

When a Foucault pendulum is suspended somewhere on the equator, then the plane of oscillation of the Foucault pendulum is at all times co-rotating with the rotation of the Earth.

What happens at other latitudes is an intermediate between these two effects..

For more information about the topic Foucault pendulum, read the full article at Wikipedia.org, or see the following related articles:

Oscillation — Oscillation is the variation, typically in time, of some measure as seen, for example, in a swinging pendulum. The term vibration is sometimes used ...  > read more

Newton's cradle — Newton's cradle or Newton's balls, named after Sir Isaac Newton is a device that demonstrates conservation of momentum and energy. It is constructed ...  > read more

Seismometer — Seismometer are used by seismologists to measure and record seismic waves. By studying seismic waves, geologists can map the interior of the Earth, ...  > read more

Coriolis effect — The Coriolis effect caused by the rotation of the Earth is responsible for the precession of a Foucault pendulum and for the direction of rotation of ...  > read more

Related Stories

Real And Virtual Pendulums Swing As One In Mixed Reality State (March 11, 2008) — Using a virtual pendulum and its real-world counterpart, scientists have created the first mixed reality state in a physical system. Through bidirectional instantaneous coupling, each pendulum ...  > read more

Pendulum Links Virtual Reality To Real System (June 18, 2007) — What's nerdier than creating an online avatar that fights dragons and raids strongholds? Creating a virtual pendulum that you can sync up to your real-life pendulum. Leave it to physicists to do just ...  > read more

Optical Atomic Clock: A Long Look At The Captured Atoms (February 8, 2008) — Optical clocks might become the atomic clocks of the future. Their "pendulum", i.e. the regular oscillation process which each clock needs, is an oscillation in the range of the visible light. As its ...  > read more

Being Isaac Newton: Computer Derives Natural Laws From Raw Data (April 3, 2009) — If Isaac Newton had access to a supercomputer, he'd have had it watch apples fall -- and let it figure out the physical matters. But the computer would have needed to run an algorithm, just developed ...  > read more

Optical Atomic Clock Becomes Portable (September 8, 2009) — Optical clocks like the strontium clock in the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig could be the atomic clocks of the future; some of them though are already ten times more ...  > read more

Search ScienceDaily

Are Saturn's Rings Disappearing?