Superconducting Trains

John writes:

Hey Marc,

This is pretty bizarre. It made some degree of sense until it was turned upside down. Any thoughts?

My reply:

Here’s another YouTube video - longer, and in English.

I’ve forgotten enough physics that it seems like magic to me. Apparently the key is what kind of magnetic field you first induce in the superconducting material. Once it’s locked in, it will maintain it, since current in the superconductor has no resistance. Magically that translates to maintenance of a fixed distance, no matter what direction the gravitational force is. Think of the roller coaster fun you can have with that!