Jumping Ring (Elihu Thomson Coil)

The plans to the right are from Brown University. Click to go there.

Jumping Ring video from MIT. Embedding disabled. More videos from Wake Forest.

.pdf plans from Sam Sampere are simplier to build.

Magnet Falling in a Copper Pipe

Not me in the video, by the way.

Eddy currents. The magnet falls far slower than you'd expect because it generates electricity in the pipe as it falls. That electricity then generates a magnetic field in opposition to the magnet's field slowing the fall. Coolmagnetman has a good site expaining what is happening and a couple of cool experiments to try with it.

Bill Beaty's (my hero!) has lots of cool stuff about rare earth magnets here including excellent plans and sources for pipe.