The Sol civilization is the name given to the galaxy-spanning, highly advanced civilization that existed before the Big Reset. The civilization collapsed as a result of the Reset, leaving the Outer Rim as the only area of the galaxy known to inhabit sapient life. The study of this lost civilization has been the focus of archeological undertakings since the foundation of the New Colonies.
Reach of the Sol Civilization
The cultural and administrative center of the Sol civilization is assumed to have been the Sol System. It seems to have spanned across most of the galaxy, with the exception of the territory now known as the Outer Rim, which was the last part of the galaxy that was still to be colonized. Early colonization of these ares was underway while the Great Reset struck. It is unknown whether or not the Sol civilization had colonies outside of the Milky Way galaxy, but it is to be assumed that at least some intergalactic exploration took place, since it is known that the Sol civilization had mastered FTL (Faster Than Light) travel as well as communication.
Within the Milky Way galaxy it is assumed that the Sol civilization had colonized the vast majority of habitable planets within the neighbourhood of the Sol System and that the collective reach of the civilization included millions of solar systems.
Level of Technology
With the knowledge of the rech of the Sol civilization it is fair to say that the level of their technology must have been immensely advanced. While archeological evidence is limited, due to the lack of large colonies around the Outer Rim, the found data suggests the existence of gigantic feats of engineering. Ecumenopolis level cities were a common occurence, as well as Dyson Swarms, planetary Rings and other megastructures. The location of these Structures is unknown.
The understanding of FTL (Faster Than Light) technology was highly advanced, which is evident in the high reach of the civilization through the galaxy. They were also in possession of technology for communication through quantum entanglement, allowing for instantaneous transfer of information over any distance.
Gene editing seems to have been a widely used technology throughout the civilization and gives us a possible explanation for the diversity of species found throughout the galaxy.
While it is not fully known how many species lived within the Sol civilization, it is assumed that the diversity of species was greater than it is today, since archelogical exploration has found remains of apparentl sapient species who can not be found among the people of the Outer Rim. The assumption is that somewhere between 80 and 90 percent of all sapient species that existed during the Sol civilization have gone extinct during the Great Reset and that the species found in the Outer Rim are the only ones left.
It is hypothesized that all sapient species known today have a common ancestor species, which may have been the main species of the Sol civilization. It can only be theorized what that species looked like and what it was called, but it is to be assumed that this ancestor species combined many traits that are common in the remaining species of today. Genetic evidence suggests that this ancestor species went extinct during the Great Reset, since none of the surviving species of the Outer Rim comes into question of being said species.
A leading hypothesis in biology suggests that the main species of the Sol civilization may have created every other species through genetic engineering. Evolutionary theory suggests that the evolution of so many species with eerily common traits is not possible without genetic meddling. The exact reason for the creation of other species beside the ancestors is unknown. Archeological findings suggest that not every species was treated equally within the Sol civilization, with some species appearing to be created for a particular purpose. It is not unlikely that many of the species we know today originally started out as being created for forced labour, specialized task or even worse.