Physics Demo Number: 20 (modified to create big bubble)Â			Approximate Run Time: 10 min
 Soap Film  Turned into Big Bubble
Demo Description  The soap bubbles requires only washing out the  black plastic tub in the [G-4-4] column and cleaning off the wire frames . Pour some soap from the ‘CostcoÂ’ brand gallon bottle of liquid soap  ( normally found  in the [H-2] column  )    to cover the bottom of the tub. Then add water till you get a pool depth that allows dipping of the frames so that when  the plane of a submerged frame is  horizontal it can be picked up and twisted vertical  to  free the frame from the pool of soap and end up with a stable film surviving intact on the frame.				Â	Scientific Principles ·         Interference of reflected light from a soap film. If the  vertical- frame- stable  film is moved by hand to the side, a large oblong bubble may be separated from the film with some practice by turning the frame back horizontal as you continue to move it to the side.
Equipment  Plastic tub Round and Rectangular Stainless Frames	Â	Equipment Location  See  notes in Description and Principles columns above.
  Instructions  Practice techniques outlined above. Writeup created by David A. Burba Copyright © 2014, Vanderbilt University.   All Rights Reserved. Â