The Ferrofluid Magnetic Bottle uses ferrofluid, a liquid that contains tiny magnetic nanoparticles suspended in a carrier fluid. These particles respond strongly to magnetic fields. When you bring the included magnets close to the tube, the magnetic field causes the ferrofluid to form striking patterns and spikes along the field lines. This happens because the magnetic force pulls the nanoparticles together, overcoming the fluid’s surface tension and creating those iconic spiky shapes.
The motion and shapes you see are a direct visualization of magnetic field lines in action. The ferrofluid moves dynamically as you change the magnet’s position, demonstrating principles of magnetism, fluid dynamics, and particle physics.