Ferrofluids
This interactive experiment deals with magnetic liquids. Under a glass dome is a bath of ferromagnetic fluid a liquid that becomes strongly magnetized in the presence of a magnetic field.
With a joystick, it is possible to apply a strong magnetic field to the Iron-spiral. The ferrofluid not just defies gravity and flows upwards on the spiral the surface also forms a regular pattern of peaks and valleys. This effect is known as the Rosensweig or normal-field instability. The instability depends on the strength of the magnetic field and its appearance can be explained by considering which shape of the fluid minimizes the total energy of the system.
