Quick Physics : The Van de Graaff generator works by static electricity, like shuffling your feet across the carpet and shocking yourself on the doorknob. Big rubber bands move over a piece of felt and strip away the felt's electrons. The electrons move up the rubber band to the metal ball and into the person. The electrons repel each other, so they try to get as far away from each other as possible. We see this effect when the volunteer's hair moves as far away from the body as it can!