Hi All: One last question about reflected sundials that I've been wondering about..
What is the mathematical formula that gives the diameter of the reflected sunspot if you know the diameter of the mirror and the projection distance? Let's say you're designing a ceiling sundial and are trying to decide how big to make your mirror. (Bigger rooms require bigger mirrors I would think. If the mirror is too small and the projection distance is very large, the sunspot would disappear I should think; and if the mirror is too large and the room is small, then the sunspot would be very big and precision would be sacrificed). As we have discussed, the projection distance and the size of the mirror are the principal factors that determine sunspot size, but I have a strong feeling that the size of the sunspot is also determined by the apparent diameter of the sun. Any thoughts on this and what the formula might be? John John L. Carmichael Jr. Sundial Sculptures 925 E. Foothills Dr. Tucson Arizona 85718 USA Tel: 520-696-1709 Email: [EMAIL PROTECTED] Website: <http://www.sundialsculptures.com>
