6H50.10 - Polarization - Scattering

Code Number:
Demo Title:
Polarization - Scattering
Polarization of Light by Particle Scattering
Area of Study:
Optics, E & M
Slide Projector, Pinhole Slide, Refraction Trough, Milk or Non-Dairy Creamer, Polarizing Plates, Eyedropper, and Stirring Rod.

Place masking plate with the 1.5" diameter hole on the overhead projector.  Over the hole in the masking plate place a beaker of water that contains some milk or non-dairy creamer.  If this is added without appreciable stirring the light emitted from the side of the beaker should be polarized.

Put the pinhole slide into the slide projector and then set the projector so that it points into the tank at an angle.  The mirror in the tank is also set at an angle so that a round oval of light is projected onto the ceiling.  Due to the index of refraction between the air and the water one of the rims of the oval is red and the other is blue or violet.  Now if you add a few drops of milk or coffee creamer, the milk particles add scattering and as the shorter wavelengths are scattered most the rims start to change colors.  If the right amount of milk is added the blue rim goes from violet to green.

The above experiment can also be used to show forward and back scattering.  Add the milk or coffee creamer to the water.  Instead of using the projector, shine a laser through the tank.  If you look at the tank from the laser position or the side you will see some back scattering.  If you look at the beam from in front of the laser you will see that the forward scattering is much more intense than the back scattering.

  • Raymond E. Benenson, "Light Polarization Experiments with a Diode Laser Pointer", TPT, Vol. 38, #1, Jan. 2000, p. 44.
  • Jay S. Huebner, "'A Golden Oldie': Projecting a Sunset", TPT, Vol. 32, #3, Mar. 1994, p. 147. 
  • Paul Chagnon, "Animated Displays IV: Linear Polarization", TPT, Vol. 31, #8, Nov. 1993, p. 489, Referenced in Resource Letter TLC-1 Teaching Light and Color, Demonstration Experiments Resource Articles.
  • G. R. Davies, "Polarized Light Corridor Demonstration", TPT, Vol. 28, #7, Oct. 1990, p. 464.
  • John D. McGervey, "Polarization of Scattered Light", TPT, Vol. 24, #7, Oct. 1986, p. centerfold section.
  • Craig F. Bohren and Alistair B. Fraser, "Colors of the Sky", TPT, Vol. 23, #5, May 1985, p. 267.
  • Wallace A. Hilton, "An Experiment on Sky Polarization and Brightness", TPT, Vol. 16, #5, May 1978, p. 294.
  • Glenn S. Smith, "The Polarization of Skylight: An Example From Nature", AJP, Vol. 75, #1, Jan. 2007, p. 25.
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  • D. E. Shaw, F. J. Wunderlich, and M. J. Hones, "Polarization Characteristics of Scattered Light", AJP, Vol. 45, #7, July 1977, p. 638.
  • "O-040. Simulated Sunset", DICK and RAE Physics Demo Notebook, 1993.
  • Richard Manliffe Sutton, "L-127", Demonstration Experiments in Physics.
  • Borislaw Bilash II and David Maiullo, "Why Is the Sky Blue?", A Demo a Day: A Year of Physics Demonstrations, p. 324.
  • Jearl Walker, "6.139. Sunglasses and Smog", The Flying Circus of Physics Ed. 2, p. 300.
  • Jearl Walker, "6.127. Sky Polarization", The Flying Circus of Physics Ed. 2, p. 295.
  • "19. Polarization of Skylight", Clouds in a Glass of Beer.
  • "Departures from Complete Polarization", Clouds in a Glass of Beer,  p. 150.
  • Robert Ehrlich, "O.1. Polarization of Scattered Light", Turning the World Inside Out and 174 Other Simple Physics Demonstrations, p. 171.
  • T. D. Rossing and C. J. Chiaverina, "7.4. Polarization By Scattering", Light Science, Physics and Visual Arts, p. 159.

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