2A15.21 - Catenoid/Catenary

Code Number:
Demo Title:
Surface Tension
Area of Study:
Heat & Fluids
2 Hoops (One Slightly Smaller than the Other) and Soap Bubble Solution.

Dip the hoops into the soap bubble solution and position so that one hoop is inside the other.  Pop the film that is in the middle of the smaller hoop.  Slowly draw the two hoops apart and the soap film should show the minimum energy catenoid.

  • Thomas B. Greenslade Jr., "Keeping Our Readers in Suspense", TPT, Vol. 56, #5, May 2018, p. 276.
  • F. Behroozi, "In Praise of the Caternary", TPT, Vol. 56, #4, Apr. 2018, p. 214.
  • Thomas B. Greenslade Jr., "An Old Favorite: The Noncircular 'Wheel'", TPT, Vol. 44, #4, Apr. 2006, p. 244.
  • James A. Flaten, "Curves of Constant Width", TPT, Vol. 37, #7, Oct. 1999, p. 418. 
  • Charles L. Adler, "Catenaries on the Computer: A Freshman Physics Assignment", TPT, Vol. 37, #4, Apr. 1999, p. 254.
  • Jeffrey R. Regester, "A Long and Bumpy Road", TPT, Vol. 35, #4, Apr. 1997, p. 232.
  • H. Richard Crane, "Three Intuition Teasers", TPT, Vol. 29, #9, Dec. 1991, p. 593.
  • R. D. Edge, "The Wobbler", TPT, Vol. 28, #2, Feb. 1990, p. 122.
  • George W. Ficken, "Catenary Curve Application", TPT, Vol. 16, #7, Oct. 1978, p. 487.
  • C. Criado and N. Alamo, "Solving the Brachistochrone and Other Variational Problems With Soap Films", AJP, Vol. 78, #12, Dec. 2010, p. 1400.
  • Robert O'keefe, "A Circular Caternary', AJP, Vol. 64, #5, May 1996, p. 660.
  • F. Behroozi, P. Mohazzabi, and J. P. McCrickard, "Remarkable Shapes of a Catenary Under the Effect of Gravity and Surface Tension", AJP, Vol. 62, #12, Dec. 1994, p. 1121.
  • Eli Honig, "New Wine into Old Bottles: A Nuptial Arch", AJP, Vol. 59, #5, May 1991, p. 472.
  • Harold S. Zapolsky, "A Simple Solution of the Center Loaded Catenary", AJP, Vol. 58, #11, Nov. 1990, p. 1110.
  • "M-837. Stand on Egg", DICK and RAE Physics Demo Notebook, 1993.
  • Tik Liem, "Fission and Fusion", Investigation to Science Inquiry, p. 188.
  • Jearl Walker, "2.122, Soap Bubble Shapes", The Flying Circus of Physics Ed. 2, p. 135.
  • Robert Ehrlich, "H.17. Water Bridge", Turning the World Inside Out and 174 Other Simple Physics Demonstrations, p. 111.

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.