"A galaxy 12 billion light years away is seen as it existed 12 billion years ago. Now look at your hand at arm's length." -Bob's sig
Explain this to me if I'm completely off the mark, but I have a problem w/ the concept that super far away stars represent images of long ago. My logic is this:
If the speed of light is finite and constant in a vaccuum, would it not be true that the (anti)matter expelled from the big bang would have had to initially travel MANY times faster than the speed of light, and then decelerated relitavely rapidly? The only way that light from a 12 billion-year old star's light could represent how it was 12 bill. years ago would be that: A) it was created MUCH later than some signifcant deceleration began to occur, and/or that B) all matter in the universe decelerates @ the exact same rate. Considering that varous celestial bodies have formed, creating varigated gravitational areas, etc. I highly doubt that. Also, the (anti)matter at the edge of the primordial "infinately dense sphere" (if it really did exist) would expand before the core did, giving it a head start.
Hmm... Since i've written all that, I think I'm beginning to piece things together. But now the question is, considering all the variables, how can we be certain that a "light-year" to us in this space-time environment is the same as other points in space-time? More simply, how do we know that light travels at a finite, consistent rate everywhere in the universe? If not, then guaging the age of celestial bodies such as stars via their energy radiation could be very unreliable indeed.