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Message: <blockquote data-quote="briggart" data-source="post: 9817722" data-attributes="member: 6805135">Sort of, but again this is mostly a coincidence. The ~46 billion light years Umbran quoted is the distance travelled by a CMB photon from its emission until it is detected by our instruments. That is the farthest we can see today . If the universe is made up just by matter (relativistic or non relativistic) or radiation, that distance would keep increasing with time so that, wait long enough, we'd be able to see every part of the universe*, superluminal recession velocities notwithstanding because expansion would be decelerating. However, it seems we are living in a universe which is mostly made up by dark energy, so in this case expansion is accelerating and it is this fact that implies that there is a finite limit to how far we can see, even with infinite time. Not expansion per se, or superluminal recession velocities. As it stands, acceleration appears to have just started, so the radius of the observable universe will keep increasing for few billion years more, but won't become much larger than what we see today.* At least in a spatially flat universe. On the top of my head, I can't remember if this is true in any possible open universe.</blockquote>