A lightning disk is cool by itself, but it's even cooler if you bring a small flourescent tube light bulb near it. The tube will light up! This is because the lightning disk generates an electric field, which excites the electrons in the atoms in the tube and makes them emit light.

• Lightning disk is available pre-made
• a small flourescent light bulb
• a box
• black paint or paper

Cover the flourescent tube bulb with clear packing tape, so that if it breaks, the glass is all contained inside the layer of tape. Tape up the ends with duct tape, so that the pointy metal contacts are covered. Tape it to a string and tape the other end to the base of the disk or the exhibit box. Paint the inside of the box black, or line it with black paper, for better visibility. Cut a small hole in the back of the box for the power cable, if the lightning disk is not battery-powered.