Re: Known Space; why so small??
well, according to this site
www atlasoftheuniverse.com/20lys html
www atlasoftheuniverse.com/50lys html
there are 83 star systems in a radius of 20 ly from Earth (40 ly diameter) and 1400 star systems in a radius of 50 ly from Earth (100ly diameter), but most of these are red dwarfs.
Its obviously a lot. But the problem with the small diamter of known space, is the fact that they DO HAVE HYPERDRIVE. Even if slow.
The area COLONIZED by mankind should be small of course. But the KNOWN space, area EXPLORED, not by simpletons, but by the Earth military and traders should be much larger than only a few weeks of travel from Earth.
A more plausible scenario, with hiperdrive similar to that of Known Space, would be some 60 light years diameter sphere with colonized star systems (not all, some of them... some on the very border of the sphere...) but known space being at least some 250 ly in diameter and constantly being expanded, by several reconessaince craft from the military and also automatic probes.
Traders following right behind, opening new routes with any civ encountered there.