Bet on a Rolling Ball

My friend and I will each allow a sphere of the same size to roll down the channel of an aluminum bracket and be stopped by a towel lying on the other end of the table. I make a bet with my friend for 99 Rubles and 10 apples that I can slow the fall of my sphere and make it stop even before the towel only by using psycho-kinetic powers and deep concentration. Further, his sphere will roll uncontrolled into the towel.

My friend takes the bet and is allowed to roll his sphere first. It flies down the aluminum bracket and reaches the towel in about one second.

I concentrate fully on my task ;-) then let my sphere roll down the bracket. Unlike my friends sphere, mine rolls slowly, requiring nearly 10 seconds to reach the table and even stops before reaching the towel. I've won the bet hands down.

The explanation: I gave my friend a steel ball but myself used a SuperMagnet sphere made of neodymium-iron-boron of the same diameter.

The rolling movement of the magnetic sphere inside the aluminum angle bracket creates a voltage of approximately 10 microvolts (Dynamo Principle). The electrical current created by this voltage differential causes a magnetic field in the aluminum. This magnetic field is out-of-phase with the magnet itself, i.e. it moves against the magnetic sphere, acting like a brake. For this reason the forward motion of the magnetic sphere is strongly reduced.