Question

They say the universe is 14 billion years old and is expanding at the speed of light, so the maximum distance from one point to another cannot be greater than 28 billion light years. Is this true?

Answer 1

answer:Cosmology, eh? From what I’ve read—and I’m a scientist, but not a cosmologist or particularly gifted with math—we don’t really know what the universe is, yet. We have a lot of elegant theories, some more elegant than others… and oddly, the most elegant ones (holarchism, E8) are often not the most popular. Rather, we rely on conceptually impenetrable and less useful postulations, such as string theory. But here are some points I’ve gleaned that can, at least, challenge the linear concept of space and time and flat expansion rate that you mentioned. 1) Light speed is not really a constant. It is dependent upon the curvature of spacetime (as put forth by Einstein’s relativity theory). 2) The expansion rate of the universe is, most likely, based on the repulsive power of dark energy, which is poorly understood and not to be confused with dark matter. 3) To quote the luminary Slick Willie, “it depends on what the meaning of ‘is’ is.” If what you mean by the universe is what we’ve seen with the Hubble Space Telescope, then yes, roughly… very roughly… it’s a spheroid in the ballpark of 28 billion light years in diameter. But a few centuries ago, we thought the Earth was the universe, and everything else was “firmament” or “heavens”, perhaps crystal ball-like objects in the near distance. Based on several sequential historical reassessments (upgrades) of our estimation of the size of the universe, it’s a good bet that we’ll figure out that A) there’s a lot more to the universe than what we can perceive with our present lenses and B) there are other universes in the multiverse. 4) Using the word “cannot” or speaking in absolutes (guilty as charged, here) is generally a flag for lack of conceptual discipline. If anything, science has taught us that the universe is messy, somewhat unpredictable though orderly, and full of surprises. Once we figure out that one point is 28 billion light years from another, we’re likely to discover some very strange things if we look a little closer: for one, that the points we’re observing are entangled with, or coexist as, others.