The equitorial drive of a telescope mount also turns at the rate of the earths rotation but in the opposite direction, so as to keep a specific point in the sky in the telescopes field of view. But you have different rates for different kinds of objects and you have to account for refraction.
> Hello; > > I have an idea to build a mechanical sundial. > > It would have a moving gnomon that would track the sun. > > If the gnomon was a hollow pipe, a spot of light would > shine out of the bottom that could be used to indicate a > time and date. > > With all of the photo voltaic systems available now the > hardware is fairly easy to find. > > I'm thinking I could use a simple dual axis photo sensor > tracking device such as this: > > http://cgi.ebay.com/Complete-Solar-Tracker-Sun-Tracker-Kit-/400187219850 > > Has anyone seen a sun dial like my idea before? > > I Googled solar tracker and they also talk about a > chronological tracker. That rotates one axis at the speed > of the earth but in the opposite direction. That would make > a fun sundial as well. > > Modern technology offers lots of new possibilities for > sundials. Is anyone trying new designs? > > thanks; > brent > > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial