Lift both discs upwards and drop them freely.
Watch the speed at which they move.
How it works
One of the discs is a magnet, the other is made of aluminium. The only force acting on the aluminium disk is a gravitational force – that is why it drops quickly. Something else happens to the magnet. The magnetic field of the moving magnet induces the so-called eddy currents in the copper pipe. They, in turn, are the source of a magnetic field with such a direction and sense of a vector that the interaction of magnetic fields results in slowing the movement of the disk.
The induction of eddy currents by an oscillating magnetic field is used in the so-called induction cookers.
Dangerous for people with artificial pacemakers!
Do not put your phone next to the magnet!
Do not put your fingers on the base of the device!