Fine Structure

MagLev Video Demo

I've seen a couple other demos of a toy maglev train from IFW Dresden before, but this one is the longest one I've seen to date. For something so simple (it's a train going in a circle), these videos are really mesmerizing.

Can anyone explain why the superconducting magnet has to be cooled down at the target height on the track? The suggestion in the video was that the train "memorized" its position on the track but that doesn't really explain what's going on. ]