Purpose:Show soap film interference and minimum energy soap surfaces.
Description:This wonderful apparatus was copied shamelessly from a corridor demonstration at the University of Minnesota. Five wire shapes are continually dipped into a tank of soap solution and withdrawn by a series of cam mechanisms on a shaft which rotates about once every 5 seconds. The type of surface which the soap solution forms can be nicely viewed as well as the beautiful soap film interference patterns. We have had it set up in a display case with switches which operate either a light or the rotation or both. Below are close-up photographs of the soap film geometrical figures.