Eddy Current Tubes
Description from Youtube:
<< Eddy Current Tubes -- Drop the Magnets down the tube. An eddy current is set up in a conductor in response to a changing magnetic field. Lenz's law predicts that the current moves in such a way as to create a magnetic field opposing the change; to do this in a conductor, electrons swirl in a plane perpendicular to the changing magnetic field.
Because the magnetic fields of the eddy currents oppose the magnetic field of the falling magnet; there is attraction between the two fi