Demonstrations

Distortion due to Atmospheric Scattering

Code Number :	6F40.10
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 :	Good
Principle :	Refraction in a Medium, Atmospheric Scattering
Area of Study :	Astronomy, Optics
Equipment :	Variac, Light bulb (100 watt), Box for Light bulb, Scattering Screens, Coffee Creamer, Beaker, Stirring Rod, Overhead Masking Plate, Pine-Sol.
Procedure :	Place the masking plate on the overhead projector. Place the beaker of water over the hole in the masking plate. Start adding small amounts of coffee creamer and stirring. As more coffee creamer is added the color projected from the overhead should go from white to orange to yellow and then eventually to extinction. During this process, you may insert different color filters between the light source and the beaker and observe how far each color travels into the beaker before it is absorbed or scattered. Hook the light bulb to the Variac. Place the light bulb in the blacked box. Hold the screens in front of the light and observe that the screens with greater amounts of particles give the fuzziest image. (Atmospheric Scattering) A couple of drops of Pine-Sol can be used in place of the creamer. This is a timed reaction so it will take up to one min. for the solution to turn cloudy. For a "timed" sunset, you can use a mixture of sodium thiosulfate and hydrochloric or sulfuric acid. Mix the thiosulfate with water until you have a saturated solution. When ready to use, dilute this saturated solution with 10 parts water. Make another solution with 2 ml of hydrochloric acid in 400 ml of water. Pour 50 ml of this into the diluted thiosulfate solution and observe the precipitation rate. ( This should turn milky white within 30 seconds. ) Dilute one or both of the solutions further until the desired reaction rate is obtained.

References

Gordon McIntosh, "A Simple Photometer to Study Skylight", TPT, Vol. 44, # 8, Nov. 2006, p. 540.

Gregory A. Dilisi and Colleen M. Winters, Lori A. Dilisi, Kristina M. Peckinpaugh, " A Beer's Law Experiment", TPT, Vol. 43, # 3, March 2005, p. 144 - 147.

E-Qing Zhu and Se-yuen Mak, "Demonstrating Colors of Sky and Sunset," TPT, Vol. 32, # 7, p. 420- 421, Oct. 1994.

William R. Kuhn and Susan E. Postawko, "Solar Radiation and the Earth's Atmosphere," TPT, Vol. 26, # 5, p. 266, May 1988.

Craig F. Bohren and Alistair B. Fraser, "Colors of the Sky," TPT, Vol. 23, # 5, p. 267, May 1985.

Joe Ferguson, "Dye Blue is Not Sky", TPT, Vol. 16, # 4, Apr. 1978, p. 243.

Thomas A. Mitchell, "Why is the Sky Blue and the Sunset Red?", TPT, Vol. 16, # 5, May 1978, p. 282.

Ben M. Doughty, A Pinch of Coffee-Mate", TPT, Vol. 12, # 2, Feb. 1974, p. 132.

Marla H. Moore, "Blue Sky and Red Sunsets", TPT, Vol. 11, # 7, Oct. 1973, p. 436.

Haym Kruglak, "A Simplified Sunset Demonstration", TPT, Vol. 11, # 9, Dec. 1973, p. 559.

A. J. Cox, Alan J. DeWeerd, Jennifer Linden, "An Experiment to Measure Mie and Rayleigh Total Scattering Cross Sections", AJP, Vol. 70, # 6, June 2002, p. 620.

Charles L. Adler, James A. Lock, "A Simple Demonstration of Mie Scattering Using an Overhead Projector", AJP, Vol. 70, # 1, Jan. 2002, p. 91.

Craig F. Bohren and Alistair B. Fraser. "At What Altitude Does the Horizon Cease to be Visible?" AJP, p. 222, Vol. 54, No. 3, March 1986.

Thomas T. Arny, "Demonstrating Atmospheric Diffraction Rings with a Tensor Lamp," AJP, p. 87, Vol. 55, No. 1, January 1987.

B. G. Eaton and John B. Johnston. "More About Light Scattering Demonstrations." AJP, 184, Vol. 53, No. 2, February 1985.

On-1: Freier and Anderson, A Demonstration Handbook for Physics.

O-040: "Simulated Sunset," DICK and RAE Physics Demo Notebook.

O-615: "Blue Sky and Powdered Cream," DICK and RAE Physics Demo Notebook.

Tik Liem, "The Confused Flashlight," Investigation to Science Inquiry, p. 289.

Tik Liem, "The Simulated Sunset," Investigation to Science Inquiry, p. 288.

"A Green Rim Demonstration," Clouds in a Glass of Beer," p. 99.

"Blue Sky," Exploratorium Hands-On Science, p. 25- 26.

Janice VanCleave, "Blue Sky, "200 Gooey, Slippery, Slimy, Weird & Fun Experiments, p. 3.

Janice VanCleave, "See Through," 201 Awesome, Magical, Bizarre, & Incredible Experiments, p. 93.

Janice VanCleave, "Thick," Astronomy for Every Kid. p. 20.

Janice VanCleave, "Twilight," 200 Gooey, Slippery, Slimy, Weird & Fun Experiments, p. 70.

Robert A. Egler, "Interstellar Medium and Stellar Reddening," PIRA News, Vol. 5, # 6, May 1991.

Ron Hipschman, "Blue Sky," Exploratorium Cookbook II, p. 95.1 - 95.3.

Ron Hipschman, "The Colors of Light," Exploratorium Cookbook III, p. viii - xvi.

"Scattering of Light," PIRA News, Vol. 9, No 3.

Shawn Carlson, "When Hazy Skies Are Rising," The Amateur Scientist, (May 1969).

5.22, "Demonstration 2", Project & Demonstrations in Astronomy by D. Tattersfield, p. 107.

5.24, "Demonstartion 3", Project & Demonstrations in Astronomy by D. Tattersfield, p. 109.

T. D. Rossing, C. J. Chiaverina, "#3, Experiments for Home, Laboratory, and Classroom Demonstration", Light Science, Physics and Visual Arts, p. 20.

Mail Questions and Comments to: Dale Stille