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[Phys-L] Buoyant cubes and magnets.

Diego Saravia pointed us to a video clip showing the dynamic effect of spinning an object on its intermediate axis of inertia.This looks quite strange in a zero-gravity field. I am reminded of two other effects: floating a cube on water and floating a magnet in air, both of which have a paradoxical aspect
A Quora user asked for the relative density of a unit cube which floats with a visible height of one tenth its unit length.One can suppose a cube might float with a face up, and edge up or a vertex up.It turns out that for a range of relative densities, the cube does NOT float face up, but rather with its top face at some lazy angle (e.g around 11 degrees) to the water surface

LevitationHere's the levitron - a magnetic spinner hovering over a magnet

or this one... .

Here's a still magnet hovering under a fast-spinning magnet