Quick math.

We don't see the tube, but assume that it is 1m long. The experimenter picks drops the 100g magnet into the tube once per second and that it has zero velocity at the tube exit. i.e. initial and final kinetic energy is zero, but the experimenter keeps inputting gravitational potential energy, all of which gets converted to heat.

Power = m * g * h / t = 0.1 * 10 * 1 / 1 = 1 W.

So, dropping a magnet every second generates 1 W of heat, which is virtually nothing.

This result is logical. The only energy input is the experimenter repeatedly moving the magnet from the bottom to the top of the pipe, and this simple movement probably won't tire him out. He could, indeed, do it all day.

Without using any math, I believe it would be a safe assumption that between the pause of reloading the magnet manually and the heat his hand would absorb by grabbing the pipe, heat would never accumulate beyond the ambient temperature in the pipe. However, it would be delightful to hear why I am wrong, since it would be very interesting.

You are correct - there's really not that much energy being converted to electric current, much less being converted from current into heat through the resistance of copper.

I would be interested in hearing what would happen if the pipe was a superconductor, though - would the induced current be so strong that the magnet wouldn't drop at all?

Superconductors have some special-case behavior with regard to magnetic fields:

http://en.wikipedia.org/wiki/Superdiamagnetism

Yes. It would hang there. That was one of the demonstrations of why superconductors are so cool back in the day. I remember seeing those nitrogen(I think) liquid cooled super conductors holding a magnet above them.

I don't think so. If I remember the explanation, superconductors "block" magnetism, rather like having another magnet with the same pole opposed. In that case, the magnet would probably just fall as though the tube was made of plastic or other non-conductor. (Just speculation, it has been several years since I read about superconductivity).

They are diamagnetic i believe (so is water' very weakly so. - google for levitating frogs for a laugh.)

Diamagnetic materials create an equal field to what they are exposed to... Causing repulsion. In the case of superconducting, the field generated is very strong and why we can levitate any old magnet over a superconductor.

Levitating a frog (mostly water right?) takes some incredibly strong fields..... Liquid cooled bitter magnets etc....

Side note - rare earth supermagets are toxic. When they shatter, you dont want to ingest any of the bits/dust

You mean...somewhat like this?

http://www.physorg.com/news/2011-10-quantum-levitating-video...

Only somewhat; it's a different set-up, of course.

Now, if only there were a way to capture that energy as electricity ;-)

Of course, all the energy is coming from his arm lifting the magnet from the bottom of the pipe to the top.

Perhaps we could set up a water mill or maybe even an internal combustion engine to do the lifting?

But we can already get energy directly from water mills and engines, and I doubt the magnet-pipe system would be as efficient.

Right. Even if we replace the pipe with a coil, it's much more efficient to just use the mechanical force directly!

I must have misinterpreted the ";-)" in your original post.

Quick, inform Tesla!