ABSTRACT
The problem of establishing what happens to the film becomes a two-dimensional one of seeing how the film links up the pins. It is identical to the problem in two dimensions of the minimum length required to join a number of points. Soap films are constrained between parallel plates such that their overall length is minimized in order to minimize energy. The equilibrium film patterns established to link up various arrangements of pins are described. To trap a single bubble within a soap-film pattern, the perspexpin arrangement is dipped into the soap solution to set up the film pattern. It is withdrawn from the solution and then reinserted to trap the required bubble. A little judicious blowing with a straw usually enables the removal of any undesirable complex patterning of the film, such as to leave a single bubble with as many sides as there are symmetrically arranged pins.
