Dear Dan: I'm thinking that when we provide answers to the FAQs we might include links to those websites which treat the subject in more depth (the excellent analemma website for example) we could also direct the sundial student to specific literature. This would save the answer committee a lot of work.
Thanks so much for your input, John Carmichael >John > >Thanks for the invitation to throw these at you. > >A couple of people have mentioned the Equation of Time as being a bit tricky, >and as a sundial novice who's also trying to crack celestial navigation >(purely out of idle interest) I'm having a hard time getting my head round >this one:- the fact that the inclination of the ecliptic to the equator >causes the sun's apparent angular velocity to vary throughout the year. I >know it makes sense, and I'm reasonably on top of the numbers, but despite >having scoured the Net for some text/diagrams which might unlock it all I >still find it difficult to visualise instinctively. Could be just a personal >mental block and you're wondering what the hell's wrong with me. > >The other bit of the EOT seems relatively straightforward as you can consider >it in just two dimensions. However, a simple diagram showing Kepler's 2nd Law >of Planetary Motion (?) with an exaggerated offset elliptical orbit would >probably be worthwhile. Made it easy for me anyway. > >I agree with the chap who recommended an illustration of each of the various >types of dial. Just beginning to get stuck into Albert Waugh's splendid book, >but there's just a couple of diagrams of sundial variants where I'm not sure >which direction I'm looking from. A simple illustration of the dial in situ, >without construction lines, would do the trick. Incidentally, I'd recommend >'Sundials, Their Theory and Construction' to any idiot like me, i.e., an >idiot who thinks he's smart but still needs everything beautifully explained >from first principles. I can see I'm going to be referring back to that one >for keeps. (Is that a highly-regarded text in the dialling brotherhood?) > >There must be loads more good questions, but you need to know a bit to know >what to ask, no? > >All the best, > >/Dan Simmons > > > > > > >
