Store up an electric charge, then make sparks.

Are you tired of electrostatic experiments that just won’t work? This experiment will produce a spark that you can feel, see, and hear. You rub a Styrofoam plate with wool to give it a large electric charge. Then you use the charged Styrofoam to charge an aluminum [...]

Some light sources may appear to wiggle and flash when you give them the raspberry, but the only thing wiggling is you

Some light sources flash on and off many times a second. When you give them the “Bronx cheer,” you can see the their hidden flickering. [...]