Demonstrations

Refraction - Variable Index of Refraction - Sugar Water

Code Number :	6A40.40
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 :	Excellent
Principle :	Variable Index of Refraction
Area of Study :	Optics
Equipment :	Optics tank, laser, jack stands, cork pad, stirring rods, front surface mirror, and sugar water.
Procedure :	Mix up 5 liters of saturated sugar water. Pour 2 liters of that solution into the bottom of the tank. With the remainder of the stock make 1500 ml solutions that are 75%, 50%, 25%, and 10% saturated. Float the cork pad on the 2 liter saturated solution in the tank and pour the 75% saturated solution over the cork pad then repeat this procedure with the other three solutions. Shine a laser in the flat end of the tank and you should see the laser beam bend toward the bottom of the tank. For an added effect you may place a front surface mirror at the point where the laser beam hits the bottom of the tank. This will give you another curved beam reflected outward. A variation on this demo is to carefully pour Ethyl Alcohol on top of a layer of water. In this case the beam will curve upward instead of downward.

References

Richard M. Heavers, "Oscillations in a Linearly Stratified Salt Solution," TPT, Vol. 45, # 4, April 2007, p. 241.

Paul Gluck, "Material and Optical Densities", TPT, Vol. 45, # 3, March 2007, p. 140.

Se-yuen Mak, "Showing the Light Path of a Mirage", TPT, Vol. 31, # 8, Nov. 1993, p. 476.

Jinsong Cui, "A Demonstration of the Apparent Ellipticity of the Rising or Setting Sun", TPT, Vol. 29, # 9, p. 566, Dec. 1991.

William P. Crummett, "Hard Rock Optics," TPT, Vol. 24, # 7, p. 414, (October 1986).

John B. Johnston, "Atmospheric Refraction", TPT, Vol. 42, March 2004, p. 184. (Reprinted from TPT, Vol. 15, # 5, May 1977, p. 308.)

John B. Johnston, "Atmospheric Refraction", TPT, Vol. 15, # 5, May 1977, p. 308.

C. Gaffney, Cheuk-Kin Chau, "Using Refractive Index Gradients to Measure Diffusivity Between Liquids", AJP, Vol. 69, # 7, p. 821, July 2001.

P. R. Barker et al, "A Superior "Superior" Mirage," AJP, p. 953, Vol. 57, No. 10, (October 1989).

A. J. Barnard, B. Ahlborn, "Measurement of Refractive Index Gradient By Deflection of A Laser Beam", AJP, Vol. 43, # 7, July 1975, p. 573.

G. Ramamurti, K. Ranganathan, L. R. Ganesan, "Solution of Legendre's Equation - Simple Proof", AJP, Vol. 40, # 6, June 1972, p. 913.

Jearl Walker, "Bouncing a Light Beam," The Flying Circus of Physics with Answers, p. 119.

C. Harvey Palmer, "A Note on the Properties of Inhomogeneous Media," Optics - Experiments and Demonstrations, John Hopkins Press, 1962

Mail Questions and Comments to: Dale Stille