Танцующая ферромагнитная жидкость

A magnetic liquid or ferrofluid is a colloidal mixture of magnetic particles (~10 nm in diameter) in a liquid carrier. Ferrofluids can be suspended in water or in an organic fluid. When no external magnetic field is present the fluid is not magnetic and the orientation of the magnetite particles is random. However, when an external magnetic field is applied, the magnetic moments of the particles align with the magnetic field lines. When the magnetic field is removed, the particles return to random alignment