Hi John, -----Original Message----- Let's say you have a spherical room, built like a planetarium, where the walls curve up into the ceiling and you locate your mirror in the center. (Actually, the room would be a quarter sphere, like an orange segment, with one flat side being the floor, and the other flat side the southern wall with the window with mirror). Would the sunspot be perfectly round all the time? Also, what would the hour and declination lines look like? (Like the lines on a hemispherium?) Would this be called an "Equatorial Ceiling Sundial"? ----- Original Message -----
I believe what you're describing is rather like the Helios XXII sculpture by Barry Mason, except he uses a pond rather than a mirror to much more dramatic effect. See http://www.rbs.org.uk/cgi-bin/getMember.cgi?member=083 Barry gave a talk on his sun sculptures at the 2000 BSS annual meeting 2000. Regards Ian Maddocks
