The Radiance setting
The past of the Radiance setting is deep and nebulous. The first age of humanity's exploration of the galaxy was a time of gradual progress across vast gulfs; the warpgates that allow convenient travel between stars would come much later. The generations that have passed since humanity was confined to a single world are so many that history has lost count. Now, few even claim to know where humanity's Eden was located.
After the cascading paradigmatic singularity culture now known as the Planck Architects disappeared, a society called the Majestic arose. Using warpgates that the Planck Architects left behind, the Majestic created an interstellar society and then an empire, spreading hudreds of parsecs along the Orion Arm of the galaxy. The Majestic believed that they would last forever, even live forever. But like the Planck Architects before them, and the Deep Timekeepers and the Transculturalists before that, the time of the Majestic would eventually end. Unfortunately, they did not simply vanish; the Majestic Empire collapsed spectacularly, with war devastating many systems and isolating others. Civilisation was splintered, societies lost a great deal of technology as communications and infrastructures fell apart, and for hundreds of years each star system, sometimes each planet, was utterly alone.
The dark age of the Collapse began to draw to a close as the relatively advanced societies in systems such as Heiraxas, Hylaeus, and Ixion rebuilt their aerospace industries and ventured back into the deeper reaches of their own star systems. They inevitably discovered the ancients' warpgates and rediscovered the means to traverse them. This age of rediscovery had its own perils and disasters; early attempts to use warpgates caused the deaths of entire spacecraft crews, and the attempted Conquest begun by the crusaders of Terannen threatened to destroy entire worlds. But these dangers encouraged the emerging worlds to cooperate with each other. Combining the different technological capabilities of each world allowed humanity to safely traverse warpgates, and a coalition of powers resisted and then defeated Terannen.
The Techno-culture emerged out of a spirit of defensive and technological cooperation. Beginning with the societies of the Ancius, Heiraxus, Hylaeus, Ixion, and Njetker star systems, it has grown to encompass twenty star systems and billions of people. The Techno-culture is founded on a philosophy of cultural diversity with an accord of common technological standards and a unified interstellar peacekeeping body. The technological accords became the Order of High Technologists, the coalition became the Armistice Interstellar Agency, and centred on the planet Iapetus in the Ixion system, a society named the Haritasi Millennium began the long task of locating and contacting every lost world of the Majestic civilisation, in the hope that one day all of humanity's daughters and sons would come together once more.
The core systems of the Techno-culture are found in three small clusters - the central group (twelve stars within a close distance of Ixion), the border group (Ogun, Kochbael, and Ahua-Kin, lying in the direction of Terannen and the Unified Interstellar Nation), and the Rimward group (five relatively isolated systems, two of which were recently discovered).
The Assembly of Core Worlds is a group of autonomous, self-governing star systems that shares a number of ideals and are located within a 15 parsec radius of the Ixion system. The Assembly grew out of the re-emerging civilisations of the late Collapse Era, which were drawn together in response to the threat of the Teranese Conquest. The original purpose of the Assembly of Core Worlds was two-fold: firstly, to protect the Core from outside threats such as that demonstrated by Terannen; and secondly, to create a new interstellar civilisation based on shared standards of science and industry.
The Assembly comprises sixty delegates known as the Peerage, and manages interstellar policies of defence, trade, and foreign relations between the Core Worlds. Each system has three Peers in the Assembly, regardless of its population, economic power, or military presence. These Peers are chosen in various ways - Ixion democratically elects its Peers, Hylaeus appoints members of its aristocratic Magnate Council, while the Peers of Autos are simply high-ranking administrators of Millennium Haritasi.
It was believed that all of the varied worlds could benefit from shared technology whilst remaining independent and culturally diverse. Although the way was initially difficult, historians agree that the Core Worlds have upheld technological homogeneity since the Interdicted Technology Accords.
The societies of the Core Worlds have different ideals about their shared past, and different expectations for the future. Scientists believe less in progress than in recovery. Scientific progress into uncharted waters is known to be perilous - while in love with technology, they fear the effects of rampant transhumanism and “the singularity.” The ancients’ civilisation is held to have been scientifically advanced, yet possessed of moral or societal flaws that led to its collapse. It is said that the ancients had such secrets of technology and philosophy, that relearning them could lead to a new golden age. At the same time, it must be remembered that the ancients’ empire did collapse, and so the moral and social mistakes of the past must be learned and avoided.
Now that interstellar society has been reborn, the universe is ready to be explored. Isolated planets, once part of a vast star empire, are just on the other side of a warp gate waiting for first contact. The Haritasi Millennium is assiduously identifying stars that may hold at least a remnant of human civilisation, attempting to calculate the warpgate configurations that will allow spacecraft to travel there, and surveying the star systems that they do find. Hundreds of reachable systems have been identified in the Periphery, as the unknown region of the galaxy beyond the core worlds is known; many of these have been visited. Many have not.
The Techno-culture is not alone as an interstellar culture. While Terannen was defeated and is now isolated from the warpgate network, seven of the systems that it controlled have become an autonomous society named the Unified Interstellar Nation, or the Unity. The sciences used by the Unity are strange, and the Unity's goals are unknown and untrusted. Very little is known about the Periphery beyond the vicinity of these seven systems.
Friendlier to the Techno-culture but no less enigmatic is a "society" of digital Minds that calls itself the TheaVon. First encountered in the years immediately before the Teranese Conquest, these artificial Minds are thought to have arisen during the Collapse and are occasionally helpful to humanity. The physical location of the TheaVon is unknown, but they are capable of communicating with almost any unshielded digital network in the known star systems.
Another society of Minds was encountered, but only once - and nothing has been heard from it since. Named the Metris, it communicated with a number of systems for approximately one year and then went silent. The TheaVon Minds have nothing to say when questioned about the Metris, and it remains one of the great unsolved mysteries.