This exhibit demonstrates how a lightning beam works.
Air does not conduct electricity, unless there is too much electricity. Then the isolation fails and a path through the air is formed. The electricity flows through this path, showing itself as a lightning like beam. A small spark starts at the bottom of a pair of “V” shaped electrodes, travelling up and getting larger as the space between the electrodes widens. The spark pops off at the top of the electrodes and the cycle repeats.