Quote Originally Posted by halfeye View Post
That implies that we eventually will, which is not what is currently thought, it is believed as I understand it that the observable universe is shrinking, because the rate of separation is rising, so the limit at which the speed of light is lower than the movement away of the expanding bits of universe is moving towards us.

I sort of expect that's all wrong, but I don't have the maths to work out how.
As far as we can tell the rate of expansion is constant. So the absolute size of the visible universe - the distance from which a photon that originated at a given point would have had the time to reach us - will only ever increase. For that to change the rate of acceleration would have to increase, we'd wind up facing down a big rip scenario, and there's no evidence that that's the likely ultimate fate of our universe.

Of course the extra space created by the expansion of space is empty, boring space. And the increased distances push away matter that's far more interesting. So in the distant future when all the local galaxies combine into one super galaxy and all the other galaxies have been pushed out past the cosmic event horizon, it doesn't matter how far out a hypothetical photon could have started out in order to reach earth by that point. What would matter is that there wouldn't be any matter or other interesting stuff that could produce such photons, so the point would be moot.