Electric fields: Lines of force shown on an OHP.

Electric fields: Lines of force shown on an OHP. This setup enables one to see the lines of force in various electrostatic field configurations. The bottom part of the apparatus consists of a thin tank of silicon oil, glycerol, and wood chips. One of the plates with the desired electrode configuration is inserted over the tank. A piezoelectric charging gun creates a temporary high-voltage electric field between the electrodes, causing the wood chips to line up with the electric field vectors. (This is a visual representation of the Teledeltos experiment performed in the labs.)