3D40.45 - Dancing Soap Bubbles

Tilt the Plexiglas or PVC tube so that the speaker end is on the table and the other end is at about the same height as the projector lens.  Place the lens so that it focuses the reflected light from the soap bubble film onto the screen.  Turn on the tape player or CD player and adjust the volume until the soap bubble starts to vibrate with the bass and midrange tones coming from the speaker.  Tracks 12 and 19 of the Tran-Siberian Orchestra CD have good bass tracks for this demonstration.
Code Number:
3D40.45
Demo Title:
Dancing Soap Bubbles
Condition:
Excellent
Principle:
Vibrating soap films.
Area of Study:
Acoustics
Equipment:
Soap bubble solution, Plexiglas tube with mounted speaker, film strip projector, focusing lens, tape player
Procedure:

Tilt the Plexiglas or PVC tube so that the speaker end is on the table and the other end is at about the same height as the projector lens.  Place the lens so that it focuses the reflected light from the soap bubble film onto the screen.  Turn on the tape player or CD player and adjust the volume until the soap bubble starts to vibrate with the bass and midrange tones coming from the speaker.  Tracks 12 and 19 of the Tran-Siberian Orchestra CD have good bass tracks for this demonstration.

 

References:
  • Goran Ramme, "Science and Art - Rotating and Vibrating Soap Films", TPT, Vol. 31, Feb. 1993, p. 124 and referenced in Resource Letter TLC-1 Teaching Light and Color, Demonstration Experiments Resource Articles.
  • Peter Insley, "Bubble Maker Interference", TPT, Vol. 26, # 3, March 1988, p. 184. 
  • Tung H. Jeong and Bailey Donnally, "Demonstration of Vibrating Membrane Using Soap Films",  AJP, 33, # 11, Oct. 1965, p. xvii.
  • W-170, "Soap Films Driven by Speaker",  DICK and RAE Physics Demo Notebook,  
  •  W-175, "Very Large Films - Glycerine",  DICK and RAE Physics Demo Notebook, 
  • "Demonstration of Vibrating Membrane Using Soap Films", Apparatus Notes, July 1965-December 1972, p. 9.
  • Jearl Walker,  "Music and Ammonia Vapor Excite the Color Pattern of a Soap Film",  The Amateur Scientist, August, 1987.

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