6F40.80 - Scattering - Fogged Glass - Halos

Astronomy Picture of the Day, Dec. 3, 2012., A Quadruple Lunar Halo Over Spain, Image Credit & Copyright: Dani Caxete
Code Number:
6F40.80
Demo Title:
Scattering - Fogged Glass - Halos
Condition:
Excellent
Principle:
Scattered Interference
Area of Study:
Optics, Astronomy
Equipment:
Laser, Screen with hole, dust, mounted regular mirror (not a front surface mirror).
Procedure:

Breath on the glass plate or microscope slide to "fog" it up.  Look throught the fog at the Maglite point source or some other distant light and observe the rainbow type rings around the point of light.  Observe that these rings may only be visible for a short time as the fog evaporates.  

References:
  • "Photo of the Month, 'Fire Rainbow'", TPT, Vol. 44, #6, Sept. 2006, p. 391.
  • Thomas T. Amy, "Demonstrating Atmospheric Diffraction Rings with a Tensor Lamp", AJP, Vol. 55, #1, Jan. 1987, p. 87.
  • E. Hecht, "Random Multiple Aperture Diffraction", AJP, Vol. 41, #5, May 1973, p. 714.
  • Robert Ehrlich, "Q.15, Diffraction of Rings Through a Mist", Turn the World Inside Out, p. 206.
  • Jearl Walker, "6.110, Colored Rings from a Misty or Dusty Mirror", The Flying Circus of Physics Ed. 2, p. 287.
  • Jearl Walker, "6.48, Frosty Glass Corona", The Flying Circus of Physics Ed. 2, p. 261.
  • N. James Bridge, "A Novel Effect of Scattered-Light Interference in Misted Mirrors", Physics Education, July 2005, p. 359.
  • Editors of Portable Press, "Who's the Rarest of Them All", Strange Science, p. 367.

Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.