1. Like i said Philip...even if it were wrong....it makes not difference ..read the rest of the post you selectively quoted from... 2 ......never mind reread it again..... Quite simple. The earth is tilted at that part of the sky. The tilt is maintained toward that part of the sky throughout the orbit around the sun, and so the star always appears in the same spot." "Ok!" I was already confirmed in what MS observed, that Steven was citing the officially accepted observation, but I wanted to now stir his education in geometry. "You are saying that if the observer moves over a base line equal to the diameter of the earth the apex of the triangle with that star will appear to prescribe a circle. Yet if the same observer moves over a base line equal to the diameter of the earths orbit, over a year, the apex of the triangle with the same star will not change its position at all." "thats right." He didn't seem to understand my simple geometrical example.. If my geometry was wrong, then he should have been able to expose the error of my reasoning.. Yet he went to the trouble to explain that the observer on the equator during our daily rotation will see a greater deviation than one closer to the poles. it is obvious that he did understand you......his answer is HC/AC dogma... 2. Even if Paul was right and the AC/HC astronomer was wrong on that issue, that whole issue is moot!... I just was not going to let Paul get away with it...However, the issue is the fact that star trails exist because of rotation around the nightly axis...(the annual axis is a real axis that is larger not smaller then the nightly one. Regardless of what size they would be "proportionally" around that axis , [earth's orbit] they should at least exist ) The rotation around that annual axis is the exact same kind of rotaion with the exact same view opportunity with the exact same stars with the same observer, camera..etc..... I cant understand why this is so hard.........Nevile, there is much work to be done.....i think we need a HC/AC sim in maya or somthing...? philip madsen <pma15027@xxxxxxxxxxxxxx> wrote: You have gotten it wrong Allen.. even if it was due to my own confused state at the time, which I cleared up later. Take this single part of yours below as an example of our combined error which Neville also corrected. PM asked : Does the view of the rotation of that star vary proportionally with the radius of rotation of the observer.. Allen 1. that is exactly what the astronomer told you.... astronomer: Quite simple. The earth is tilted at that part of the sky. The tilt is maintained toward that part of the sky throughout the orbit around the sun, and so the star always appears in the same spot." ..that astronomer probably misunderstood my question or I did. We were confusing angle to the horizon with angle of observation . old subject. look carefully at the above.. as selected here this question, Does the view of the rotation of that star vary proportionally with the radius of rotation of the observer.. got this answer, Quite simple. The earth is tilted at that part of the sky. The tilt is maintained toward that part of the sky throughout the orbit around the sun, and so the star always appears in the same spot." Which is as Neville said, a big NO NO. The answer is, "no." The stars are so far away in the heliocentric idea that the difference in radius between R and 1AU is negligible (manifesting itself only in tiny parallax and slightly elliptical trails as opposed to circular trails). The rest of your post is irrelevant. The point has been resolved. Philip