[redrobein]

Any conductive material for the tube will have a similar effect. It isn't specific to copper.

The moving magnet induces a current in the tube which in turn creates the magnetic field that interacts with the magnet.

[TheSpiceIsLife]

Not any conductive material, obviously won’t work won’t work, nor magnetic steel / stainless steel alloys.

[TheSpiceIsLife]

I meant: obviously iron won’t work.

[soligern]

Eddy currents

[sjcsjc]

“Eddies,” said Ford, “in the space-time continuum.”

“Ah,” nodded Arthur, “is he? Is he?”