Demonstrations

Thin Film Interference - Soap Films

Code Number :	6D30.20
Disclaimer:	Reprinted by permission of Dick Berg, University of Maryland, for use on this website. The demonstrations contained and referenced herein are listed for the purposes of cataloging and describing physics demonstrations which should be conducted only under the direction of a trained instructional support professional or physicist. These demonstrations are not presented for the purpose of being conducted by persons unconnected to this Facility and/or persons not consulting with or being supervised by the recognized instructional support professional or physicist and his/her staff. The University is responsible only for those demonstrations carried out using its own equipment using established safety and scheduling policies, and bears no responsibility for those choosing to use this source material for their own purposes. All demonstrations described and contained herein are public domain, and can also be found in reference materials in libraries, bookstores, and electronic sources. Further information regarding legal liability in use of demonstrations and labs will be found on the web site Injuries in School/College Laboratories in USA. The University of Iowa Disclaimers: University of Iowa Disclaimer All Rights Reserved..
Condition :	Good
Principle :	Thin Film Interference
Area of Study :	Optics
Equipment :	Enclosed box with bubble maker and bubble liquid, Film Strip Projector, 8 inch by 8 inch 252mm lens, Bubble Blowing Liquid, Bubble Blowing Rings and Accessories, Fluorescent Light (if needed), Video Camera and Power Supply, Book: Soap Bubbles by C. V. Boys, Focusing Lens, Bubble Kit, 2-L bottle with hole in bottom.
Procedure :	The enclosed box with bubble maker and bubble liquid should be ready to go with no preparation. The procedure is to shoot light from the projector into one face of the box, and the image of the bubble will be reflected onto a screen at a 90 degree angle to the incident light. This is due to the bubble maker being set at a 45 degree angle inside the box. The large 8 inch by 8 inch, 252 mm lens is then used to focus the reflected image on the screen. For the classroom conditions that we usually experience a bubble mixture of our own making seems to work best. The mixture is as follows: 8 oz. of 'Wonder Bubble', 1 to 2 oz. of 'Joy' dishwashing Liquid, 1 to 2 oz. of Glycerin. To observe better thin film interference use 2 to 3 times as much glycerin. When you want to observe thin films influenced by gravity, support the bubble ring on a stand and look through the film onto a white screen background. The pattern can be easily seen in reflected light. A bubble will also show the interference pattern, but is usually harder to view or project. An inexpensive bubble holder that will enclose the bubble and make it last for long periods of time can be made from a 2-L bottle. Poke a hole in the bottom of the bottle and suck the soap film in through the mouth. When the bubble is well into the bottle, screw on the cap. This can be used on the overhead projector.

References

L.M. Gratton and S. Oss, "Soap, Colors, Holes, and Much More", TPT, Vol. 43, # 6, p. 338, (Sept. 2005).

James Huhn, "Cheap Interference," TPT, Vol. 34, # 1, p. 5, (Jan. 1996).

Andrew DePino, Jr., "Making Permanent Thin-Film Interference Patterns," TPT, Vol. 33, # 4, p. 228, (April 1995).

Haym Kruglak, "Thin-Film Interference Bands", TPT, Vol. 33, # 6, Sept. 1995, p. 326.

Bill Reid, "Animate Glue", TPT, Vol. 33, # 6, Sept. 1995, p. 326.

G.R. Davies, "Interference and Diffraction Corridor Demonstrations," TPT, Vol. 33, # 4, p. 244 - 247, (April 1995).

Goran Ramme, "Videotaping the Lifespan of a Soap Bubble," TPT, Vol. 33, # 9, p. 558 - 561, (Dec. 1995).

Goran Ramme, "Colors on Soap Films - An Interference Phenomenon," TPT, Vol. 28, # 7, p. 479, (October 1990).

Peter Insley, "Bubble Maker Interference", TPT, Vol. 26, # 3, March 1988, p. 184.

Chris Chiaverina, "An Interactive Soap Film Apparatus", TPT, Vol. 26, # 4, Apr. 1988, p. 238.

H. L. Armstrong, "Interference Colors in Thin Films", TPT, Vol. 17, # 5, May 1979, p. 311.

John A. Davis, "Soap Film Interference Projection", TPT, Vol. 12, # 3, March 1974, p. 177.

Phillip E. Highsmith, "The Beautiful World of Interference", TPT, Vol. 8, # 5, May 1970, p. 270.

Sidney E. Lang, "How Thick Is a Soap Bubble?", TPT, Vol. 8, # 6, Sept. 1970, p. 335.

L. J. Bruner, "Stable Black Soap Films," AJP, p. 177, Vol. 53, No. 2, (February 1985).

Ol-16: Freier and Anderson, A Demonstration Handbook for Physics.

O-465: "Soap Film-Flat & Hemispherical," DICK and RAE Physics Demo Notebook.

O-467: "Colors in Soda Bottle", DICK and RAE Physics Demo Notebook.

Jearl Walker, "The Bring Colors in a Soap Film Are a Lesson in Wave Interference," The Amateur Scientist, (September, 1978).

C.L. Stong, "How to Blow Soap Bubbles That Last for Months or Even Years," The Amateur Scientist, (May, 1969).

Brown, "Rainbows in a Bubble," 200 Illustrated Science Experiments for Children, p. 123-124.

"Bubble Tray," Exploratorium Science Snackbook, p. 16.1 - 16.2.

Louis Pearl, "Bubble Bubble-ology Guide," Tangent Toy Co. 1995.

Raymond Bruman, "Soap Bubbles," Exploratorium Cookbook I, p. 10.1 - 10.2.

Robert Ehrlich, "Colorful Soap Bubbles," Why Toast Lands Jelly-Side Down, p. 173-175.

Robert Ehrlich, "Interference in Thin Films," Turning the World Inside Out, p. 205-206.

Ron Hipschman, "Soap Film Painting," Exploratorium Cookbook III, p.172.1 - 172.3.

"Soap Film Painting," Exploratorium Science Snackbook, p. 89.1 - 89.2.

"7.3: Interference and Diffraction," Cunningham and Herr, Hands-On Physics Activities, p. 467.

"Low Cost Bubble Holder", Tap-L Discussions.

Mail Questions and Comments to: Dale Stille