The main story arc of the Dryden Experiment takes place in the early 26th century by the Gregorian Calendar. In this universe, humans have, for almost 200 years been capable of interstellar travel thanks to framing technology, sometimes called the "Insanity Crystal"
Using framing drives, humans have colonized a strip of star systems 300 light years long and 100 light years wide roughly centered on Sol and following the curve of our spiral arm of the Galaxy. Exploration craft have ventured much father into the surrounding galaxy but limitations in communication make it difficult to track or follow this exploration in any detail.
Among "Main Line" systems (a loose term used to mean star systems near Sol or colonized 100 or more years ago) governance is mostly by the controlling corporation. There several large and many small multi-star system corporations: Syrch, Terracorp., and Lin being the three largest and oldest. The outer star systems vary from small colonies, to independent single planet nations. In theory all planets with human inhabitants are protected under the League of Planets. This organization has little real power most of the governance is done either by the local company or by the local governing body.
Already, humans have begun adapting to their host planets. People from planets with high gravity tend to be short and stocky with dense muscle and bone structures, while humans living in relatively gravity free environments tend to develop long, lean bodies with low muscle density.
Humans are not alone in the galaxy. In any given star system, there is about a 65% chance that there will be at least one life bearing planet. In about 8% of star systems there are two or more life bearing worlds. These range from highly complex biospheres like Earth to planets entirely covered in Methane, and Hexane eating sludges. Humans are also not the first interstellar species in the Galaxy. Archaeological evidence suggests that one interstellar species or another has colonized this part of the Galaxy every 100,000 to 500,000 years. The home worlds of these species and the reason for their downfall have never been uncovered. The evidence of previous civilizations is so scant that some humans believe they are a hoax.
(To Be Continued)