Foucault's pendulum - 2

Last year when scientists mounted a pendulum above the South Pole and watched it swing, they were replicating a celebrated demonstration performed in Paris in 1851. Using a steel wire 220 feet long, the French scientist Jean-Bernard-Léon Foucault suspended a 62-pound iron ball from the dome of the Panthéon and set it in motion, rocking back and forth. To mark its progress he attached a stylus to the ball and placed a ring of damp sand on the floor below.

The audience watched in awe as the pendulum inexplicably appeared to rotate, leaving a slightly different trace with each swing. Actually it was the floor of the Panthéon that was slowly moving, and Foucault had shown, more convincingly than ever, that the earth revolves on its axis. At the latitude of Paris, the pendulum's path would complete a full clockwise rotation every 30 hours; on the Southern Hemisphere it would rotate counterclockwise, and on the Equator it wouldn't revolve at all. At the South Pole, as the modern-day scientists confirmed, the period of rotation is 24 hours.

The swing of Foucault's pendulum depends on the way we set it into the motion. If we set the pendulum in motion by a short push at the position of equilibrium it will swing as it is shown in animation. Actually the speed of the pendulum in the extreme positions is the speed of the earth rotation in the point of observation.

When we set the pendulum in motion by a short push at the position of equilibrium it will swing as it is shown in the second animation. Actually the speed of the pendulum in the extreme positions is the speed of the earth rotation in the point of observation.

http://physics-animations.com/

Category:

Science & Technology

Tags:

• physics
• mechanics
• animations
• education
• learning
• pendulum
• oscillation
• earth
• rotation
• experiment
• science
• university

[Randomnod]

@PawelKolasa That's incorrect. The electromagnets only help to maintain its constant motion. It's like having an unlimited supply of fuel in your gas tank; it doesn't affect the direction of the car, only the distance it travels. The pendulum falls victim to friction due to air resistance, so the electromagnet counters those forces so that the experiment can continue and the main focus of the project can be observed. In a frictionless environment, it would never stop swinging.

[thomasgoodey]

It is in English. This is a physics video, and it requires some level of linguistic and mechanical competence to understand what is going on.

[jtban1611]

Is there any relation between the rotation of the stars and the rotation of the pendulum? Stars rotate CCW around the celestial north pole; the pendulum rotates CW. Stars rotate CW around the celestial south pole; the pendulum rotates CCW. Both stars and the pendulum do not rotate at the equator.

jtb

[prk30]

@Noshoesworn By the way, with your exigences you are not certain if Earth rotates, until an independent observer reproduces the experiment.

[prk30]

@Noshoesworn . Revision by specialists can confirm ou impugnate such elements in a given test, what leads to the conclusion that peer-reviewing is a way to discuss a experiment, but it does not “adds” science to it.

[prk30]

@Noshoesworn Peer-reviewing is only a rule to publish experiments in scientific publications, not a rule of the science speech. It has nothing to do with the internal logic of the experiment itself, neither with the logic nexus with factual premises, demonstration process, verification criteria and results. All these must be found in the structure of the proposed experiment.

[rafalokasioo]

@Noshoesworn thats because not everybody can use a steel wire 220 feet long, suspend a 62-pound iron ball and calculate the exact flux of magnetic induction necessary to counter the friction... and THEN, build a foulcault's pendulum... you moron

[independence8]

to explain the motion one needs to take into account the coriolis force!

[darkqueen12]

@PawelKolasa

The magnets aren't there to make it move, it's there just to make sure that pendule continues moving despite the interaction with air, and the movement of a pendule is independent from the earth, so what is beneath that pendul is connected to earth and is affected by its rotation, that's how we prove earth turns.

And what you said is just stupid, you treated something that has been in place for years by great scientist as fake?! You are fake!

[johnbunsenburner]

@geneous42 A pendulum, without any other device(such as a tosion spring) would not swing if no external force were applied, instead it would rotate around the point to which it is fixed (since gravity pulls the pendulum back down when it reaches its apex).