wellis wrote:What year or century would this take place in?
This is something I've been wavering on for a while. Originally, I said the 100th millennium in order to allow for a true transgalactic civilization to spread out across the galactic disk. Keep in mind that Accelerating Future involves a long period of time where relativistic travel, time dilation, and biostasis/uploading where the only ways to spread across the universe, which naturally puts a cap on how fast civilization can expand. Recently, though, I've decided to scale things back by having the modern era - let's call it the Transgalactic Era for now - start sometime in the 60th millennium. Part of the reason for this is because the intergalactic aspect of the setting has been scaled back somewhat in importance. Civilization has covered the galaxy, but it has yet to full harness its true potential and material wealth, nor have all of its wonders, secrets and horrors been fully cataloged in the galactic core, the halo, or other rough and tumble territories. There are extragalactic shenanigans going on, but its mostly limited to outposts and colonial territories established by deep spacers, private groups, or roving macrolife civilizations in the Magellanic Clouds or the dwarf satellite galaxies, though you never know how far out those deep spacers might go, or where an abandoned Tipler machine might take you.
In terms of the timeline, I'd say it roughly looks like below. This is somewhat transhuman-centric, but it gets the point across.
Solar Era - >3000CE
Humanity's history prior to stepping out in the greater universe. The Accelerando causes the emergence of many radical new technologies: genetic engineering, cybernetics, Artificial Intelligence, brain uploading, rudimentary nano/microtechnology, advanced robotics, rapid automated manufacturing, megaengineering, and and robust alternative energy. While these breakthroughs unleash great positive benefits for all of humanity, future shock causes similarly great instability for the global community, as institutions and societies struggle to adapt to the new paradigm. Major sociopolitical realignments and revolutions lead to the birth of a new world order, as multinational federations and alliances absorb the old nation-states and new and/or heavily altered political and economic systems replace obsolete models.
The solar system becomes covered in the sprawl of civilization, from the growing urbanization of Mars and Venus to the shell of habitats encapsulating Jupiter and Saturn. While dominated by first by the multinationals, the growing power of the colonies and the flourishing of new ideologies and movements leads to new polities linked together at the planetary level. The solar system is more or less divided between the populous Inner Worlds, the anarchic industrial-economic-technological juggernauts of the Belt and the energy barons of the Outer Rim.
Interstellar Era - 3000CE - 20,000CE
Transhumanity begins its push across the known universe, setting the groundwork for its emergence as an interstellar civilization. Progress is slow at first, limited to generation ships, seedships, and upload-crewed vessels. In time, relativistic starships and even true lighthuggers crisscross the void, connected disparate worlds isolated by distance and time. A combination of relativistic travel, time dilation, sophont augmentation, and biostasis effectively opens up the galaxy to exploration, colonization, and exploitation. Thanks to the growth of laser comm-based interstellar cloud networks and the lighthugger exchange set up by deep spacers, the first interstellar polities form. The limit imposed by Einstein means that said polities are radically different from anything seen before, being more of an association of like minded worlds and systems that agree to share ideas and defend one another. Alien civilizations are also encountered, some stuck at neolithic levels while others have established booming interplanetary or even small-scale interstellar civilizations, and long-range observations, which have also detected civilizations comparable to transhumanity in scope scattered across the galactic habitable zone and beyond, indicate that the number will only go up. At its height, transhuman civilization encompasses many thousands of light-years of space and billions of worlds.
The Great Diaspora - 20,000CE - 40,000CE
The ability to generate wormholes had already been known by the late Interstellar Era, but they were almost always small and short lived, requiring astronomical levels of power to generate anything larger or stable. A better understanding of the science behind wormhole generation and improvements in the machinery needed to expand and stabilize wormholes from the quantum foam would lead to practical traversable wormholes. Worlds that were once separated by centuries or millennia became practical next door neighbors, sparking an unprecedented surge in socio-political and cultural cross contamination, a flowering of technological acceleration, and the formation of a stable interstellar community. Transhumanity and its nearby alien peers would not be the only interstellar civilization to experiment with such transportation methods, however. Across the galaxy, alien civilizations that had the technological expertise to do so would experiment with traversable wormholes and krasnikov tubes. In time, true independent supraluminal travel would emerge thanks to the interstellar renaissance of new technologies and ideas. Expansion, already having been accelerating thanks to the network of wormhole gates, would explode exponentially. As the secret of FTL was spread by the deep spacers, more cultures would join the in fray, leading to a great diaspora of galactic proportions. Different species, cultures, ethnicities, and clades would intermingle with one another, while the first true large-scale interstellar federations, alliances, and empires would be born during this era, leveraging supraluminal travel and communications to create stable unions across many thousands of light-years. The beginnings of a true transgalactic community of worlds could be seen during the latter years of the Great Diaspora, as many looked to the future with great optimism.
The Bifurcation of Civilization 40,000CE - 50,000CE
Action! Intrigue! Basically, the era leading up the formation of the true transgalactic community. The rise and fall of enormous empires, the 1500 year long Infinite War, the emergence of the direct predecessors to the modern transgalactic superpowers, the occasional cosmic horror run amok, continued exploration and colonization, though the conflicts and political intrigue of the era prevent it from matching the same levels of enthusiasm as seen in previous eras. The challenges faced in this era would inspire many polities to emphasize cooperation and the safeguarding of Civilization against threats to its stability. The true transgalactic community is born.
Transgalactic Era - 50,000CE - Present
The current era. Civilization is sprawled across the Milky Way and its immediate environs, though it has yet to exploit its potential to the fullest. The transgalactic community, now a mature astropolitical entity - is dominated by a clique of galactic superpowers, though there are countless thousands of polities across all spiral arms and galactic regions that adhere to its standards. Talk occasionally arises of transforming the transgalactic community into a
de facto federation, though that seems to be a long ways from ever occurring. The current frontiers of Civilization include the Deep Galactic Core, the Outer Rim Territories, and the Galactic Halo, where young colonies grow, new opportunities arise, and hazards are numerous. But to those who succeed there are vast rewards. Much like the Pre-Interstellar Era, a few have ventured beyond the known universe and have established extragalactic outposts and colonies, ensuring the inevitable spread of Civilization across the greater universe (and possibly beyond). Science and technology are surging forward, while the exploration of the universe continues with a renewed zeal.
On the edges of Civilization are many threats; the Ouster Territories - worlds and polities that refuse to acknowledge the legitimacy and authority of the transgalactic community - are a constant thorn in Civilization's side, particularly in its frontiers. The autocratic Quentithian Combine, a vast interstellar empire that has absorbed hundreds of polities, is only peripherally connected to the transgalactic community due to mutual mistrust, having its own ideas for the known universe that could very well put it at odds with its neighbors. Whispers of cosmic horrors that lurk in corners of the known universe and beyond are many, though how credible they are is suspect. The transgalactic community is ready to face these threats, however, and will do everything necessary to ensure that their hard work is never undone.
I should note that this timeline is strictly in-universe; I doubt Civilization would name their eras like I did. Basically, each era is meant to be modular in the sense that they could stand alone as their own separate universe if needed, yet also build on previous eras to create a vibrant and living setting.