Your username reminds me of a "magic trick" I used to do when I volunteered as a presenter at my local science museum and was stationed at the electricity and magnetism section. To demonstrate Lenz's law, I had a magnetic ball and copper pipe and when you drop the magnetic ball through the copper pipe it falls slowly. This is just physics as even though the copper pipe isn't magnetic, it is conductive and so the very strong magnet creates strong eddy currents. I would give the ball and pipe to guests to show them they could do it themselves. I was actually given two magnetic balls, so I came with a plan to spice things up with a trick. I would palm another magnet in my hand and when they handed the pipe to me, the ball would not just fall slowly but would never come out because it was attracted to the other magnet. Then I would hand the pipe to them and the ball would then fall out since it was away from my palmed magnet. While explaining the electromagnetism to them I would put the magnet in my hand in my pocket pretending I was getting my badge or something. No guest ever figured out my trick, probably because they were expecting a science trick and not a magic one. But it's funny to think that I used to do this as a joke. It was a little deceptive but I told anyone who asked it was a magic trick.