Skip Navigation

J2-14. Lightning Rod Simulator


To demonstrate how lightning rods really work.


Van de Graaff generator with ground sphere, ground wire with point.




A ground sphere is positioned adjacent to the Van de Graaff generator so that the ground sphere is charged by induction and creates large sparks. While this system is working, a grounded point is aimed at the Van de Graaff dome from a distance of several times the distance between the dome and the ground sphere. The grounded point discharges the dome at a much lower potential, preventing buildup of charge on the ground sphere and the concomitant spark discharge. ◙◙An apparently controversial theory of how a lightning rod works uses this experiment as a model. Being a point, the lightning rod◙a


Price and Crowley, The Lightning-Rod Fallacy, AJP 53, 843-848, (1991). ◙I. M. Benn and S. T. Shanahan, Of lightning rods, charged conductors, curvature, and things, AJP 59, 658-660 (1991). ◙E. R. Doubek, Living with Lightning, Popular Electronics, 32-34, 96, (Oct. 1990). ◙Richard Stone, Electical Storms: Violent and Creative, The Washington Post, A3, (July 30, 1990). ◙M. A. Baker and J. G. Dash, Charge Transfer in Thunderstorms and Surface Melting of Ice, Journal of Crystal Growth, 97,◙770-776, (1989). ◙Richard E. Orville, The Lightening Discharge, TPT 14, 7-13, (1976). ◙Walter Thumm, Question