The two balloon demo is well done in the film: "Surface Tension and Fluid
Mechanics". This film features an engineer *pointing* at some equations,
but it also has some fantastic examples of surface tension being modified
by heat, charge, etc. If you locate the film being offered on videotape or
disk, let me know, as all I had access to was the old 16mm version. Karl
Dr. Karl I. Trappe Desk Phone: (512) 471-4152
Physics Dept, Mail Stop C-1600 Demo Office: (512) 471-5411
The University of Texas at Austin Home Phone: (512) 264-1616
Austin, Texas 78712-1081