6D30.20 - Thin Film Interference - Soap Films

Code Number:
6D30.20
Demo Title:
Thin Film Interference - Soap Films
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 252 mm 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, and 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:
  • Paul Hewitt, "Figuring Physics", TPT, Vol. 60, #9, Dec. 2022, p. 770.
  • Daniela Rapava, "Freezing Bubble", TPT, Vol. 53, #4, Apr. 2015, p. 256.
  • Leslie J. Atkins, "Thin-Film Interference Using a Computer's Screen and Camera", TPT, Vol. 49, #1, Jan. 2011, p. 62.
  • L. M. Gratton and S. Oss, "Soap, Colors, Holes, and Much More", TPT, Vol. 43, #6, Sept. 2005, p. 338.
  • Göran Rämme, "Videotaping the Lifespan of a Soap Bubble", TPT, Vol. 33, #9, Dec. 1995, p. 558.
  • Bill Reid, "Animate Glue", TPT, Vol. 33, #6, Sept. 1995, p. 326.
  • Haym Kruglak, "Thin-Film Interference Bands",TPT, Vol. 33, #6, Sept. 1995, p. 326.
  • G. R. Davies, "Deck the Halls: Interference and Diffraction Corridor Demonstrations", TPT, Vol. 33, #4, Apr. 1995, p. 244.
  • Andrew DePino Jr., "Trick of the Trade: Making Permanent Thin‐Film Interference Patterns", TPT, Vol. 33, #4, Apr. 1995, p. 228.
  • Göran Rämme, "Colors on Soap Films–An Interference Phenomenon", TPT, Vol. 28, #7, Oct. 1990, p. 479.
  • Chris Chiaverina and Joe Pizzo, "An Interactive Soap Film Apparatus", TPT, Vol. 26, #4, Apr. 1988, p. 238.
  • Peter Insley, "Bubble Maker Interference", TPT, Vol. 26, #3, Mar. 1988, p. 184.
  • H. L. Armstrong, "Interference Colors in Thin Films", TPT, Vol. 17, #5, May 1979, p. 311.
  • Robert Gardner, "Teachers' Pet III:"How Thick is a Soap Bubble?", TPT, Vol. 14, #1, Jan. 1976, p. 40, also A Potpourri of Physics Teaching Ideas - Fluids and Heat, p. 124.
  • John A. Davis, "Apparatus for Teaching Physics: Soap Film Interference Projection", TPT, Vol. 12, #3, Mar. 1974, p. 177.
  • Sidney E. Lang, "Apparatus for Teaching Physics: How Thick Is a Soap Bubble?", TPT, Vol. 8, #6, Sept. 1970, p. 335.
  • Phillip E. Highsmith, "Apparatus for Teaching Physics: The Beautiful World of Interference", TPT, Vol. 8, #5, May 1970, p. 270.
  • Y. D. Afanasyev, G. T. Andrews, and C. G. Deacon, "Measuring Soap Bubble Thickness with Color Matching", AJP, Vol. 79, #10, Oct. 2011, p. 1079.
  • F. Behroozi and D. W. Olson, "Colorful Demos with a Long-Lasting Soap Bubble", AJP, Vol. 62, #9, Sep. 1994, p. 856.
  • David T. Kagan and Louis J. Buchholtz, "Demonstrations of Normal Modes on a Bubble Membrane", AJP, Vol. 59, #4, Apr. 1991, p. 376.
  • L. J. Bruner, "Stable Black Soap Films", AJP, Vol. 53, #2, Feb. 1985, p. 177.
  • Jearl Walker, "The Amateur Scientist: The Bring Colors in a Soap Film Are a Lesson in Wave Interference", Scientific American, Vol. 239, #3, Sept. 1978, p. 232.
  • C. L. Stong, "The Amateur Scientist: How to Blow Soap Bubbles That Last for Months or Even Years", Scientific American, Vol. 220, #5, May 1969, p. 128.
  • "O-467. Colors in Soda Bottle", DICK and RAE Physics Demo Notebook, 1993.
  • "O-465. Soap Film-Flat & Hemispherical",  DICK and RAE Physics Demo Notebook, 1993.
  • G. D. Freier and F. J. Anderson, "Ol-16", A Demonstration Handbook for Physics.
  • Don Rathjen and Paul Doherty, "Soap Film in a Can", Square Wheels, 2002, p. 101.
  • Bill Franklin, "Observing Colors in a Soap Film", Teaching about Color & Color Vision, 1996, p. 3C-3.
  • Bill Franklin, "Understanding Interference Colors", Teaching about Color & Color Vision, 1996, p. 2C-4.
  • Jodi and Roy McCullough, "Thin Film Interference with a Soap Bubble", The Role of Toys in Teaching Physics, p. 4.162.
  • Jodi and Roy McCullough, "Simple Machines with a Bubble Machine", The Role of Toys in Teaching Physics, p. 4.80.
  • Pat Murphy, Ellen Macaulay, and the staff of the Exploratorium, "Soap-Film Stars", Exploratopia, p. 310.
  • Borislaw Bilash II and David Maiullo, "How Thin Is the Film", A Demo a Day: A Year of Physics Demonstrations, p. 354.
  • Jearl Walker, "6.119. Anticounterfeiting: Color-Shifting Inks", The Flying Circus of Physics Ed. 2, p. 292.
  • Jearl Walker, "6.116. Pearls", The Flying Circus of Physics Ed. 2, p. 291.
  • Jearl Walker, "6.115. Structural Colors of Insects, Fish, Birds, and Monkey Butts", The Flying Circus of Physics Ed. 2, p. 289.
  • Jearl Walker, "6.114. Colors of Oil Slicks, Soap Films, and Metal Cooking Pots", The Flying Circus of Physics Ed. 2, p. 288.
  • Ed Sobey, Woody Sobey, "Bubble Gun", The Way Toys Work, p. 28.
  • 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, "11.3 - Colorful Soap Bubbles", Why Toast Lands Jelly-Side Down, p. 173 - 175.
  • Robert Ehrlich, "Q.14. Interference in Thin Films", Turning the World Inside Out and 174 Other Simple Physics Demonstrations, 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.
  • James Cunningham and Norman Herr, "7.3. Interference and Diffraction", Hands-On Physics Activities with Real-Life Applications, p. 467.
  • "Low Cost Bubble Holder", Tap-L Discussions.

Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.