Fine Structure

by qntm

It's Sol Earth Gregorian Common Era Five Four Three Five. (It's probably a million other years, too, depending on where you're from and how you count them. Here at the edge of the multiverse, where all humanity eventually arrives, the popular epoch of late is the Yuur Unambiguous Era, in which the current year number is The Smallest Year Number Not Currently In Use Anywhere Else. It's currently YUE 189, but sooner or later a traveller is going to arrive whose own epoch was 189 years ago, causing YUE to conscientiously jump forward to 190 to avoid the clash.) Universe +1 is the first of approximately 1.84E13 parallel universes arranged in a closed circle in hyperspace. Because most Earths are still, to within acceptable tolerances, firmly rooted to their original orbital track, stepping between parallel Earths is substantially simpler than stepping from planet to planet within a solar system, let alone crossing a universe to reach other stars. So even though many parts of the multiverse have FTL travel, the Earth-shaped core of the multiverse is where almost everything happens. Almost every conceivable eventuality is happening out there on the strand somewhere, on some Earth. Every historical path has been taken, for better or worse. There is cross-universe communication, trade, cultural exchange, technological exchange, colonisation, invasion, conflict and war. There are perfect shining lights and completely extinguished graveyard universes which neighbouring Earths use fo...