Its magnetic fluid. Feel free to make your own with print toner, and oil! Its dangerously carcinogenic of course...
(, Sun 5 Oct 2008, 15:32, Reply)
Ferromagnetism only works because the metal atoms are close enough together in the solid state to undergo magnetic superexchange - I wonder what makes this stuff work?
(, Sun 5 Oct 2008, 15:59, Reply)