ELECTROMAGNETIC ALUMINUM LEVITATOR
Photograph by Sam Murphy
POWERS OF INDUCTION
This simple AC-powered coil device uses magnetism to levitate aluminum rings and shoot them into the air — and aluminum isn’t even magnetic!
About 13 years ago I learned of some military research into a satellite- and missile-defense device that would propel projectiles using Lenz’s law, which governs the direction of electrical current induced by a changing magnetic field. I decided to make a little gadget based on the same principle for my kids, to get them interested in science and electronics. The gadget worked — both at levitating and shooting ...