In a message dated 1/8/2002 4:19:42 AM Eastern Standard Time, [EMAIL PROTECTED] writes:
> Since a caustic is a very different animal from an image, is there any > chance of getting around the 2 minute limit on sundial accuracy due to the > sun's angular diameter? Art, I can't address the issue of caustics, but the 2 minute barrier can be broken by using two focused images of the sun, side-by-side, separated by a tiny amount of space. This space could be, say, 15 seconds of time, and would serve as the time indicator. If you have any doubt that this is feasible, I have a close up photo of my dial which operates using a single focused image of the sun, and although the image is 2 minutes wide, it is readable to better than 1 minute. The edges of the image are razor sharp, and it is easy to see that a design with two of these images side-by-side is achievable. Someday I may make one, but it is not high on my list of things to do. This JPEG is available to any who request it. Bill Gottesman Burlington, VT 44.4674N, 73.2027W
