It looks more like a charcoal briquette than anything, but the black brittle thing at the bottom of [Ben Krasnow]’s crucible is actually a superconducting ceramic that can levitate magnets when ...

WHAT YOU NEED: stationery to make a small box, cardboard, insulated wire, wire cutters and sandpaper, an LED bulb and strong ceramic bar magnets. STEP 4 - CONNECT LED: Cut the wire to leave two ...