Polarization -  Tyndall Experiment


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 Code Number :   6H50.20  

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.

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Condition :   Excellent  
Principle :   Polarization of Light, Rayleigh Effect  
Area of Study :  Optics, E & M   
Equipment :   Laser, Silver Nitrate Solution, Large Florence Flasks, Polarizing Plate, Pine-Sol, Non-Dairy Creamer or Milk, Stirring Rod.

  
Procedure :   Rayleigh Effect: Fill a large Florence flask with filtered water. Aim a laser down the neck of the flask as shown.  A polarizing filter should be placed between the laser and the flask unless you are using a polarized laser.  Add a few drops of fresh silver nitrate and look into the side of the flask and as moving 360 degrees around the flask observe the scattered, polarized light. The silver nitrate must be made fresh just before the demonstration as it starts to combine with minerals in the water over time. The polarized light intensity as you go around the flask may be measured with a light meter.

Pine-sol or powered non-dairy creamer will work in place of the Silver Nitrate, and are more environmentally friendly.  However, they do produce a more complicated scattering pattern because of their larger particle size.  

In the file with the laser manuals there is a Metrologic Laser Handbook and Catalog which has 101 uses for a laser described in it including this demo.  

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   References

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

Samuel Derman, "Light Pipes, Hydrostatics, Surface Tension and a Milk Carton", TPT, Vol. 22, # 1, Jan. 1984, p. 42.

 

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

 

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

 

Robert A. Egler, "Interstellar Medium and Stellar Reddening," PIRA Newsletter, May 1991.

Robert Ehrlich,  "Polarization of Scattered Light,"  Turning the World Inside Out.

Joey Green, "Underwater Blue Light Beam", The Mad Scientist Handbook, Vol. 2, p. 101.



Mail Questions and Comments to:  Dale Stille