John, I remember this argument from a paperback on relativity that I read many years back, but I have never been very happy with the assertion. It seems to me that sunlight travels in straight lines in space and so the is sun still above the horizon if you can see it. I suppose that you can extend the imagined plane of your local horizon into the the rest of space instantly (i.e. this thought process is not limited by the speed of light). Otherwise, what about the stars? Did a star in the sky near your sun 'set' many light years previously? The earth rotates thousands of times during the passage of light from a star.
I would think that 'setting' is a phemomenon that occurs on earth and is independent of the source distance. Mike Manning. -----Original Message----- From: Philip P. Pappas, II <[EMAIL PROTECTED]> To: sundial@rrz.uni-koeln.de <sundial@rrz.uni-koeln.de> Date: 20 January 1999 16:24 Subject: speed of light > Dear Slawek and others: > >We could make this question even more complimented if we consider the speed >of light. When we see the sun's center on the horizon we are seeing light >that left the sun about 8 minutes earlier. The sun really has already set. >(of course this has no practical effect on sundial time, but is fun to think >about!) > >Thanks for your comments > >John Carmichael > >
