This comes courtesy of Taylor S:
This is a video about ferrofluid. Ferrofluid is a liquid that becomes strongly magnetized when exposed to a magnetic fluid. Ferrofluid is composed of a ferromagnetic solute is dissolved in a solute. The spikey portions are where the electromagnetic field is the strongest. I love ferrofluid because of the really cool-looking and interesting shapes it makes when the electromagnetic field is turned on and off.