Fenerit wrote:Yeah, Andrea: all the time do you have need! It's just for a strange idea that brought to my mind: if those systems were erroneos for the real world, probably even in Celestia it do not works! How do you think to give at that systems those two contemporary motions without violate the Kepler's laws? Perhaps the solution (in educational mode) should be a cmod sphere mapped with the stars and planets as "mirrors", that turns indipendently from the annual motions of planets around the Earth. Was the impossibility of having this two motions at the same time that lead Ptolemy in consider your system apart of physical reality.
I'm not so expert of Ptolemy's feelings with his system, even if I know of his dissatisfaction for the results, being imperfect and moreover possible only with a lot of "inventions" (Mars. Jupiter and Saturn epicycles all orbiting in 1 year, just for an example, or the line connecting Mercury and Venus epicycles center linked to Sun's orbit (Sun is the only object not moving along an epicycle, you know), in order to explain the East-West movement around the Sun of these two planets.
I would be not so sure of what you say about the Celestia impossibility to draw something against Kepler's laws, because I'm looking just now at Mars, Jupiter and Saturn taking the same time to orbit the Earth's equant, and Mercury-Venus equant barycenters linked on a straight line from Earth's equant to the Sun, so... the third Kepler?€™s law is OFF, do you agree?
Regarding the Almagest stars, they are already drawn on a cmod sphere, but sincerely we have not yet faced the problem of its rotation.
As I told you, the stc and ssc expert of our team is Buggs Moran, actually on holiday, so upon his return we?€™ll go back to the drawing board.
Bye soon
Andrea
