Keyser wrote:McAz wrote:And - if I've got this right - we reach an interesting problem if Einstein is correct. That is, the light from anything beyond around 14 billion light years away from us will never reach us since the expansion of the universe is happening faster that the speed of light. So we may never know how big the visible universe is beyond that point by direct observation. This, of course, assumes we are correct in ageing the universe to around 14 billion years old.
Hence the term Observable Universe.
So in a stroke we have the size of the universe for humans and other lifeforms bound by 4-dimensional spacetime - 14 biilion light years in any direction (give or take a few hundred million light years).
Well that's one branch of science we can cease giving grants to.