Both GS and HC are essentially just a mathematical coordinate systems for what we observe here on Earth. A method for calculating how far away and where something is going to be at any given time in the heavens when we look up. The appearance of motion is identical, It is the theoretical motion that gets the stars and planets to the right place at the right time that differs. However, at externally large distances any discrepancies in the two methods for achieving those positions will show up. This is due to the fact that a ~.0000005 of a angel at the point of origin is imperceptible to the observer at the point of origin, however at 430ly away it will displace ~7926 miles. The average male is 5?6". Relatively specking the displacement of that angle at that distance is overwhelmingly enormous compared to the observer. The further away the earth is from a given star the smaller the angle will be but so to will the displacement of whatever that angle is. Basically, we as the ob servers will always be microscopic compared to the displacement of the angles at those distances, thus we can observe this phenomena quite readily. It is interesting to note that the HC have estimated Polaris' distance from Earth to be everywhere from 360 to 820 light years . The 430ly figure is from the Hipparchus satellite estimates. j a <ja_777_aj@xxxxxxxxx> wrote:"Incidentally, these star trails can only be explained by a rotating universe, rather than by a rotating World." Why is this true? I thought that the appearance of motion in either HC or GC were the same? --------------------------------- Do you Yahoo!? Yahoo! Small Business - Try our new resources site!