Something that drew me into superconductivity when I was an undergraduate student thinking myself about what to do when I was introduced to superconductivity and levitation in particular, I thought this is magic. If the wheel would not have been and went so far, we would not need any more, we can do it just by levitation. There is a settled difference between levitation and suspension. Perfect levitation requires ideal mice in the state and is not possible to suspend superconductor under deferromagnet. Suspension requires magnetic flux to penetrate the interior of superconductor and be pinned. All of the things floating magnets and floating trains can see that there is virtually no loss as the magnet moves across the superconductor. This is readily understandable in terms of forces on the magnet because the magnet is moving in a uniform field so there is no force on it. However, if you look at it from the point of view of the superconductor, you have got these pinned flux lines. So one might ask why are these being pulled along with the magnet? Which is an interesting question. The answer is that the flux lines can cut and join in free space. This is something which is not easy in a superconductor, but in free space in the right geometry, the flux lines can cut and rejoin because the flux lines don't actually exist. This is true in a uniform field, it's only when you've got non-uniformities that changes and movement will cause you to have forces.