Giant films: photos and movies

by
Dr. Maarten A. Rutgers

These photos were taken on April 27, 1996, at the Carnegie Science Center in Pittsburgh. Most were taken by Urbashi Mitra, and a few by Maarten Rutgers (copyright). Videos were made by Brian Martin.

Movies

The film is started with the two nylon vertical wires together. Once soap solution has had time to dribble to the bottom, and the wires are completely wet, we pull the vertical wires apart using a secondary set of thinner strings. You can see people standing behind the film who are doing this. As the wires spread, we increase the flow rate to keep up with the film's demands.
Quicktime Movie (1.0 MB, be patient while loading)

Once started the film can last for minutes. It is affected by air currents and dust. It never really dries out, since it is constantly being replenished from the top, and draining into a bucket at the bottom. We managed to get it as wide as the whole atrium, about 15 feet. By opening and closing the flow rate control valve, you can change the thickness, and thereby the color, of the flowing film
Quicktime Movie (1.4 MB, be patient while loading)

Someone standing 8 feet behind the film is blowing against it. If you blow with all your might, and wait a few seconds, you can get the film to bulge out.  Stop blowing, and it relaxes back.  While bulged, the film simply flows around the obstructing airmass.
Quicktime Movie (0.6 MB, be patient while loading)

Photos

You can click on any photo to see it enlarged.
A typical soap film, at 1 to 2 meters wide, as seen from the ground floor. The boom from which the wires hang is visible at the fourth floor railing. Also note the strings which separate the main bounding lines. Once the film is more than a meter wide, one can blow at the film to produce large undulations. The film proceeds to flow around the undulation. Here Douglas Miller attempts to close the wires to separate a bubble.
A typical view from the top of the channel. The film terminates at the ground floor in a 50 gallon trash can. Note its size for scale. A similar photo. One sees both interference colors and also reflected colors from the red and white features on the museum walkways.
Another bottom view. Note the expression on the face of the small boy looking over the second floor railing. (expanded for detail) This tended to be the reaction of most people, including ourselves.