Luke Coletti <[EMAIL PROTECTED]> writes: > Now I'm not sure I understand what you mean by Perihelion > being fixed relative to the stars. If it is moving (eastward) I > don't see how it can be viewed as fixed. Also, Perihelion isn't > shifting due to precession, like the Equinoxes, instead perturbation > and relativistic effects are the cause.
I meant effectively fixed, in the sense that it hardly moves on the 10,000 year time scale we are talking about. Is that right? What is the period of the shift of the Perihelion? I also thought that the shift of the Perihelion was referred to as "precession", but I may be wrong. I realize that it is based on other physical effects than the precession of the Equinoxes. For the Earth, isn't the perturbation due to Jupiter the only significant cause? I think the other planets, the relativistic effects, and the gravitational quadrapole moment of the sun can all be neglected. Art Carlson
