A great way to demonstrate a basic principle of electrostatics. The metallized ball, when first brought near the dome, is attracted by induction until it touches. It is immediately charged to the full dome potential and repelled. The ball then floats at a distance from the dome. The silver snake is also attracted by induction, but as soon as it touches the dome, it too is repelled. Where as the ball retains the charge, the ribbon does not and repeatedly strikes back!