I have some trouble understanding the evolution of the universe. If I understand correctly, the universe started at a single point, and expanded outward from that point. Now, billions of years later, we (and all of the other mass points in the universe) are receding from the original big bang point. We are told that we can “look back” to the early universe, because the light we see from distant stars is millions, perhaps billions of years old. Yet, because material bodies (stars, planest, etc.) cannot move at even a small fraction of the speed of light, I would think that the wave front of the ancient starlight would long since have passed us by.
So how old, is the oldest light that we can see (from the original center of the universe)?
As I understand it, the matter in the Universe is actually expanding outwards at pretty near the speed of light. The Universe itself is bound by no speed limits, just the stuff it contains.
(Expecting to be corrected by others.)
A few things:
The Big Bang did not occur as a single point expanding into a big ball although that analogy is commonly used. As such, there is no center to the universe (or conversely you can think of every point as the center…take a smooth, featureless sphere and point to the center on the surface of the sphere…there isn’t one).
As far as looking back goes although light (or energy) from distant sources reached us long ago it is not as if there is only one wave front and then it’s gone. It’s like a constant stream and we continue to see energy from distant sources.
The most distant object ever viewed (which corresnponds to how far back in time we are looking) is a quasar some 12 billion light years away ( http://www.berkeley.edu/news/berkeleyan/2000/04/26/sextans.html ). That places it at roughly one billion years after the Big Bang.
Finally, if you really want to twist your noodle, there is a thing called Inflation Theory used to describe the very, very early moments of the universe where it is speculated that the Universe expanded faster than the speed of light. If that theory is true then there is more Universe beyond what we can ever see. While Inflation is just a theory I think it is a fairly well respected one.