The "floating magnet trick" is shown in Figure 10.50. If the disk on the bottom were a permanent magnet, rather than a superconductor, the trick wouldn't work. The superconductor does produce an external field very similar to that of a permanent magnet. What other characteristic is necessary to explain the effect? (Him: What happens when you hold two ordinary magnets so that they repel, and then you release one of them?)

We need to explain why replacing a superconductor with a permanent magnet on the bottom disk will fail the floating magnet trick.

Superconductors exhibit the Meissner effect, making them perfect diamagnetic materials. When two magnets are held together so that they repel, releasing one of them will at first push it away and then eventually rotates and places itself at an angle and can turn 180° and attach its opposite pole with the other.

Permanent magnets are made of ferromagnetic materials that carry magnetic fields in bulk although they can exhibit zero resistance to low temperatures, due to their ferromagnetic property, the field lines do not get totally repelled and can pass through the material thus "failing the floating magnetic trick"