A hundred billion years from now, any galaxies not now resident in our neighborhood (a gravitationally bound cluster of about a dozen galaxies called our β€œlocal group”) will exit our cosmic horizon and enter a realm permanently beyond our capacity to see unless future astronomers have records handed down to them from an earlier era, their cosmological theories will seek explanations for an island universe, with galaxies numbering no more than students in a backwoods school, floating in a static sea of darkness. We live in a privileged age. Insights the universe giveth, accelerated expansion will taketh away.
β€” Brian Greene The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos
Tags: space, science