Imagine you have a pice of pie. At the center of that pie you draw a angle of 1 degree. 1 inch away from the point of origine of the angle now at the edge of the pie that same one degree will be proportionaly larger than the part at the point of origin. If you create a angle which is ~.0000005 of one degree, 430LY away that angle will take up ~7000 miles of space. Allen j a <ja_777_aj@xxxxxxxxx> wrote: What do you mean by "the displacement of that angle will be proportionally larger"? How is that angle displaced? Measuring a stars distance in HC or GC, each system will produce an angle according to its' assumptions and that angle remains the same. Allen Daves wrote:Correction: This is what I meant. The further away the earth is from a given star the smaller the angle will be but the displacement of whatever that angle is will also be proportionally larger. Allen Daves wrote: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 w hatever 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 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! --------------------------------- Do you Yahoo!? Yahoo! Small Business - Try our new resources site!