Physics Photo of the Week

Warren Wilson College

October 15, 2004

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Moonrise over Willoughby Lake, Vermont

Several physical phenomena are illustrated in this scenic view of the full moon rising above Willoughby Lake, Vermont.  The photograph was made soon after sunset on July 29, 2004.

The most obvious phenomenon is "specular reflection".  Specular reflection is the reflection of the moon's image in the foreground by the relatively smooth water.  The reflection is called "specular" because the reflection is caused by the partial reflection by a surface (water or glass) which has a different refractive index from air.  You can see a similar specular or partial reflection of light with an ordinary window - especially when you are trying to see inside a house from the outside.  The moon's image in the foreground is distorted by the small waves on the lake. 

There are at least two additional optical phenomena demonstrated in the photo.  See if you can identify the other optical effects.  Click on this link to see the answers.

Total Lunar Eclipse - October 27, 2004.   Don't forget the total lunar eclipse Wednesday, October 27, 2004.  This eclipse is visible over much of the Western Hemisphere (see Sky and Telescope web site).  The moon begins its entry into earth's dark shadow at 9:14 pm EDT, the eclipse will be total from 10:23 pm to 11:25 pm.  The Warren Wilson Physics Department will have telescopes for public viewing at the Garden Cabin on Warren Wilson Campus.  Please: no alcohol or tobacco use at the public viewing.  Click here to see images of an eclipse in May, 2003.

Due to Fall Break there will be no Physics Photo of the Week next week (October, 22).  The next Physics Photo of the Week will be published soon after the eclipse -  October 29, 2004.

Photo by Donald F. Collins, Warren Wilson College

Physics Photo of the Week is published weekly during the academic year on Fridays by the Warren Wilson College Physics Department.  These photos feature an interesting phenomena in the world around us.  Students, faculty, and others are invited to submit digital (or film) photographs for publication and explanation.  Atmospheric phenomena are especially welcome.  Please send any photos to

Click here to see all Physics Photo of the Week for 2004.