A balloon filled with a gas that has a different sound speed than that of air has been used as an acoustic lens. One purpose of the lens is to show refraction of sound waves in an analogy to geometric optics. We discuss the physics of the balloon lens demonstration. To determine the validity of a gas-filled balloon as a classroom demonstration of an acoustic lens and to understand the corresponding phenomena, its physics is considered analytically, numerically, and experimentally. Our results show that although a geometric analogy is a good first-order approximation, scattering theory is required to fully understand the observed phenomena. Thus this demonstration can be adapted to a wide range of students, from those learning the basic principles of refraction to advanced students studying scattering.
Skip Nav Destination
Article navigation
March 2009
PAPERS|
March 01 2009
A balloon lens: Acoustic scattering from a penetrable sphere Available to Purchase
Derek C. Thomas;
Derek C. Thomas
a)
Department of Physics and Astronomy,
Brigham Young University
, Provo, Utah 84602
Search for other works by this author on:
Kent L. Gee;
Kent L. Gee
Department of Physics and Astronomy,
Brigham Young University
, Provo, Utah 84602
Search for other works by this author on:
R. Steven Turley
R. Steven Turley
Department of Physics and Astronomy,
Brigham Young University
, Provo, Utah 84602
Search for other works by this author on:
Derek C. Thomas
a)
Department of Physics and Astronomy,
Brigham Young University
, Provo, Utah 84602
Kent L. Gee
Department of Physics and Astronomy,
Brigham Young University
, Provo, Utah 84602
R. Steven Turley
Department of Physics and Astronomy,
Brigham Young University
, Provo, Utah 84602a)
Currently at the University of Texas at Austin. Electronic mail: [email protected]
Am. J. Phys. 77, 197–203 (2009)
Article history
Received:
February 06 2008
Accepted:
November 13 2008
Citation
Derek C. Thomas, Kent L. Gee, R. Steven Turley; A balloon lens: Acoustic scattering from a penetrable sphere. Am. J. Phys. 1 March 2009; 77 (3): 197–203. https://doi.org/10.1119/1.3041420
Download citation file:
Pay-Per-View Access
$40.00
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Citing articles via
All objects and some questions
Charles H. Lineweaver, Vihan M. Patel
On the analogy between spinning disks coming to rest and merging black holes
Domenico Davide Meringolo, Francesco Conidi, et al.
Ergodic Lagrangian dynamics in a superhero universe
I. L. Tregillis, George R. R. Martin
Quantum solutions for the delta ring and delta shell
Luis F. Castillo-Sánchez, Julio C. Gutiérrez-Vega
Detecting gravitational waves with light
Markus Pössel
Online “Advanced Labs” in physics
Peter A. Bennett
Related Content
Physics of a balloon lens
J. Acoust. Soc. Am. (May 2007)
A ray model of sound focusing with a balloon lens: An experiment for high school students
J. Acoust. Soc. Am. (March 2012)
Using a High-Speed Camera to Measure the Speed of Sound
Phys. Teach. (January 2012)
Investigating Diffusion and Entropy with Carbon Dioxide‐Filled Balloons
Phys. Teach. (September 2010)
Fidelity of infrasound measurements with balloon-borne sensors
J. Acoust. Soc. Am. (December 2024)