Flat Black is set in space around Earth in a notional future¹ of the real world². It is therefore set in three-dimensional space³ (which is not such a problem because it isn’t a space opera and therefore players don’t have to use maps) set with real stars. I used to have a big problem with the fact that the best available catalogues of near-by stars (Gliese & Jahreiß until 1990, Gliese’s Third Catalogue of Nearby Stars from 1991) were lacking the important K-type stars beyond about 50 light-years and G-types beyond about 70. It wasn’t that the stars that would be important places in Flat Black were unknown or un-named: they weren’t in the catalogues because their distances hadn’t been determined). Fortunately the Hipparcos project came along and millions of parallaxes have been determined by a robot. I am using the Extended Hipparcos Compilation (EXHIP) as my catalogue of stars for Flat Black: it brings together Hipparcos location data with everything else known about the corresponding stars as at 2012. That is sufficiently complete (lacking only dim M-class stars that I don’t care about) out to about 50 parsecs. The star list I use for Flat Black is an extract from XHIP, consisting of 10,401 stars within 200 light-years of Sol.
The planets orbiting those stars I generated using a modified⁴ version of the star system and advanced planet generation procedures from GURPS Space 4th edition. And I re-ran the universe generation 169 times to get one I liked⁵. That gave me a universe of places with definite planetological characteristics and a defensible density of habitable worlds in space. A mathematical model of exploration and colonisation using just-as-fast-as-light technology starting in AD 2059 gave me 640 colonisation ventures sent forth by AD 2353⁶. Of the inhabited worlds, 997 are planets and only 3 are moons.
So. In Flat Black there are 1,000 worlds known⁷ to be inhabited by humans. They are all within 175 light-years of Sol, a volume containing about 8,000 stars. Given that the Galaxy is about 140,000 light-years in diameter and contains about 200 billion stars that makes Human Space a tiny, tiny globule, only about one twenty-millionth of the Galaxy⁸. Indeed, as the Galactic disk is about 2,000 light-years thick, the 350-LY diameter of Human Space is still small compared with the thickness of the disk.
Of those, 625 are “primary colonies” that were settled directly from Earth. The primary colony nearest to Earth is Tau Ceti on Tau Ceti II, which is 856 years old and 12 light-years from Sol. The most distant is Feilong on HD 83517 IV, which is 459 years old and 147 light-years from Sol. The median distance from Sol of the primary colonies is 116.7 light-years. The average nearest-neighbour distance for the primary colonies is 14.8 light-years.
The remaining 375 colonies are secondary colonies founded by emigrants from colonies rather than form Earth. Almost all were settled using faster-than-light ships; this gave wider choice, allowed the settlers to choose only worlds with higher salubrity, and has made the secondary colonies somewhat farther apart than the primary ones.
The stars these systems orbit are mostly F-type, G-type, and early K-type, with some outliers. The hottest is 16 Lambda Aquilae, an B9, which is the sun of the colony Ardour. It is followed by nine A-type stars. The coolest are Hip 46018 and Gliese 1184, type M0V, the suns of Hennah and Kaiyen respectively.
Now, starships⁹ in Flat Black travel at about 1000c (about 6 parsecs per week). That means that the minimum interstellar journey (i.e. from one’s home-world to its nearest neighbour) takes 5.4 days each way (plus the time it takes to get from surface to orbit and out to a safe distance from the planet to use an Eichberger drive). To reach Feilong from the Capital takes 54 days. To reach the farthest new settlements from the core — or to cross human space — takes about 64 days. It is these long travel times (rather than fares, which are not exorbitant) that limit human travel between the worlds and make the colonies isolated.
Not only are the colonies socially and culturally isolated from each other, but Imperial heads of mission and chiefs of bureaux are weeks or months each way from the Imperial capital at Sol. The Empire attempted to reduce this problem by establishing “Sector HQs” between about 100 and 120 light-years from Sol, where they concentrated reinforcements and senior officers to back up their local missions at need. But the geometry is not favourable: even with Imperial reserves divided among twenty sectors the average primary colony is 41.8 light-years from its nearest SHQ and the most distant, Stockbrook at Zeta Cygni is 73.5 light-years from its SHQ (orbiting Logos at Gliese 9830).
The Imperial sectors and their SHQs are as follows:
Sector | Star | Colony |
---|---|---|
Central | Sol | The Capital |
Ursa Major | Gliese 3712 B | Saguenay |
Sextans | Gliese 3603 | Khujandi |
Libra | HD 133352 | Blackstone |
Draco | HD 146868 | Qinglong |
Gemini | HD 49736 | Franklin |
Cassiopeia | Gliese 3185 | Dehúdié |
Cetus | HD 18702 | Ramotswe |
Centaurus | HD 109252 | Mesta |
Corona Australis | Gliese 4096 | Nicole |
Reticulum | HD 25120 | Newhome |
Pisces Austrinus | HD 217343 | Sehausie |
Andromeda | Gliese 9830 | Logos |
Puppis | n Puppis | Vingilot |
Aquarius | HD 197210 | Sparta |
Eridanus | HD 28287 | Danubia |
Hercules | HR 6981 | Gawain |
Virgo | Vindemiatrix | Laurens |
Leo | Gliese 3580 | Silotimia |
Hydra | HR 4803 | Walden |
¹ Flat Black is not an attempted prediction of anything.
² Or perhaps in the future of an alternative universe that is just like this one except for having no God or souls, all mental phenomena being physiological phenomena.
³ I’m sorry but insistent, Traveller fans. 2D maps of 3D space are mathematical nonsense, like a “map” that placed every location in the USA on a line from San Diego CA to Caribou ME.
⁴ The first modification was that the gadget reading in data from the star catalogue instead of generating it at random. The system architecture table has been altered to give more realistic (i.e. much lower) numbers of eccentric and epistellar gas giants. I altered some things to give continuous bell-curve distributions instead of discrete 3d6 distributions. I fixed the rules for tides. I altered the timing of the Ocean➔Garden transformation (the “Oxygen Catastrophe”) according to the proportion of sunlight suitable to drive photosynthesis….
⁵ Perhaps I ought to have done a bunch more so that I could have the Muslim theocratic utopia on Zawijah orbiting Beta Virginis. Having it on Hijra orbiting p Eridani is something that I have to fix.
⁶ I tried extending the age of emigration to restore the 800 worlds that I had in earlier versions. A destruction of Earth in AD 2403 gave me 858 settled worlds, but economic development and population growth on Tau Ceti were threatening to make it a second Earth and start despatching its own emigrants. So I wound the destruction of Earth back to AD 2353 and accepted 625 surviving primary colonies as enough.
⁷ I do want lost colonies at great distances, established by misjumps, by reckless colonists accepting worlds on the basis of telescopic observations alone (Bofinger colonies), and by pirate fleeing the Formation Wars in FTL ships. I haven’t got around yet to working out what’s plausible and where they are.
⁸ At the current rate of population growth and current population density it will take humans about 850 years to fill up the Galaxy. Nothing to worry about.
⁹ Passenger liners, anyway. There might be some freighters that are slower and cheaper.
¹⁰ Oops! A footnote!