A permanent magnet levitating over a superconductor is found to spontaneously spin, overcoming resistance to air friction. We explain the physics behind this remarkable effect.
@article{arxiv.cond-mat/0303574,
title = {Spontaneous spinning of a magnet levitating over a superconductor},
author = {J. E. Hirsch and D. J. Hirsch},
journal= {arXiv preprint arXiv:cond-mat/0303574},
year = {2009}
}
Comments
See http://physics.ucsd.edu/~jorge/spinning.html for movie clips of the effect