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A Foucault pendulum is a pendulum allowed to oscillate in 2 directions, unlike the pendulum in a clock which is restricted to 1 dimensional oscillation.

On Earth, (except at the equator) the plane of the pendulum's motion will slowly rotate, demonstrating that the Earth's frame is rotating.

enter image description here Source

In orbit, a pendulum would have to use a different restoring force, A spring pendulum is one example but there could be others.

While the Earth's frame rotates once in about 24 hours, a space station in LEO rotates about 16 times faster, about once every 1.5 hours.

Has similar phenomenon to the Foucault pendulum ever been demonstrated in orbit for purely educational, fun, or scientific purposes?

For the purposes of this question, gyroscope precession doesn't count. This needs to be a pendulum's oscillation induced by a restoring force.

If there's video, something like this illustration of the tennis racket theorem by space tourist Richard Garriott, that would be great!

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  • $\begingroup$ The single spring pendulum will not work in zero gravity, at least two springs in opposite direction will be necessary for oscillation. But on Earth Foucault pendulums should be very large to show the effect. I doubt a small pendulum in orbit would show the frame rotation. The pendulum should oscillate for at least half an hour, not easy for a small one. $\endgroup$ – Uwe May 9 at 8:20
  • $\begingroup$ @Uwe what kind of spring has been powering wristwatches, pocket watches and clocks for hundreds of years? commons.wikimedia.org/wiki/File:Alarm_Clock_Balance_Wheel.jpg Wouldn't one of these, allowed to rotate about a 2nd axis, do the job nicely? Also, as far as I know, at least for a gravity pendulum the size is important only to reduce damping and has nothing to do with rate. The rate is simply 360 degrees/day times sin(latitude). $\endgroup$ – uhoh May 9 at 8:37
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    $\begingroup$ For another striking demonstration of the intermediate axis theorem, see the dancing handle. $\endgroup$ – Michael Seifert Jun 4 at 15:31
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    $\begingroup$ A "mass on a spring" oscillator in space would keep oscillating along a fixed axis in space while the ISS rotated around it. I would worry that any Coriolis rotation of this apparatus would be masked by rotations induced by air currents. You'd also have to release it precisely enough that it didn't have any initial rotation relative to the ISS, or the residual angular momentum would also mask the desired effect. Effectively, you need some way to guarantee that the mass's oscillation axis will stay fixed in space axis for a significant portion of an orbit. $\endgroup$ – Michael Seifert Jun 4 at 15:57
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    $\begingroup$ Don Petit did some demonstrations of physics in zero-G for students and also did a bunch of other random cool experiments I'd recommend checking out. The time he spent on the ISS was never wasted because he enjoyed playing with random objects he could find in zero-G and relaying results he'd observe to people who might be interested. Saw him talk and he was pretty proud of some papers he got published simply because he was "playing with X" as he put it. $\endgroup$ – Magic Octopus Urn Jun 4 at 16:51

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