Things You'll Need
Instructions
Place a magnet into the bottom of the clear plastic or glass tube, with its north pole facing upward. The magnet itself needs to be a round-style magnet slightly smaller than the width of the tube.
Construct the floating magnet of enough magnets that it won't be able to spin while it is in the tube. If the magnet is only slightly smaller than the tube, it may be possible to use only one magnet, though its chances of getting stuck in the tube are greatly increased, because it is trying to spin.
Place the tube on a flat surface, with the magnet at the bottom of the tube and the opening at the top of the tube. Drop the magnet you constructed so that its north pole is facing downward. When the magnet reaches the magnetic field of the magnet in the base of the tube, it will bounce as though it were connected to a spring. It will then settle and float above the magnet at the base of the tube.