Here, we see a skull magnet interact with a mass of ferrofluid. A ferrofluid is a liquid that becomes strongly magnetized in the presence of a magnetic field. Ferrofluid was invented in 1963 by NASA’s Steve Papell as a potential liquid rocket fuel. Basically, they are colloidal liquids made of nanoscale ferromagnetic particles suspended in a carrier fluid (usually an organic solvent or water). Yes, this is how strangely they behave in the presence of a magnetic field.