clipped from magazine.wustl.eduOn August 8, 2008, a group of sundial enthusiasts met in St. Louis to tour 15 area sundials, some of historical importance, including one on the campus of Washington University that is marking its centennial anniversary. The sundial on the Cupples I building façade, donated by the Class of 1908, faces south on Brookings Quadrangle. The motto on the sundial is "I am a shadow/So art thou/I mark time/Dost thou?"
| The sundial on the Cupples I building façade on view in Brookings Quadrangle marks 100 years in 2008. |
The tour, organized by Donald L. Snyder, senior professor of electrical and systems engineering in the School of Engineering & Applied Science, was one component of the 2008 Annual Conference of the North American Sundial Society.
Sundials can be traced to antiquity and come in many designs. Some are elaborate and beautiful, others plain and practical, but all measure time by the position of the sun. Key components of sundials are a shadow-casting object called a gnomon and a surface with lines indicating the hours of the day and important dates.
Two other sundials exist at the University, one inlaid on a sidewalk between Crow Hall and the Earth & Planetary Sciences Building and the other in that building itself on a Mars rover-scaled replica. The sundial is in use on Mars with Spirit and Opportunity for color calibration for the rovers' cameras.
The core of sundials is a stew of mathematics and physics. "I'm interested in them because of their mathematical relation to the position of the sun at any time," says Snyder, who has made a number of portable, wooden sundials for family members. "It is a thing of beauty to design an instrument on the basis of mathematics, the physics of solar and Earth motion, and the effects of sunlight."
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