Thursday, June 16, 2011

Time and travel

Lets say for the sake of argument that the average distance to the FTL transit limit is equivalent to the orbit of Jupiter; we'll also assume that in each system we have to cross the system (that is, travel twice the Jupiter semi-major axis) to get to the right place to transit to the next star, and that we start and end that crossing at zero velocity.  Lots of assumptions there that the final software will do in detail; and we are ignoring trade stops and refueling.  Given all of that, here's a data table:

Time .01G .1G .2G .3G .8G 1G 2G 3G
sec 8E+06 2E+06 2E+06 1E+06 9E+05 8E+05 6E+05 5E+05
min 1E+05 4E+04 3E+04 2E+04 1E+04 1E+04 9E+03 8E+03
hour       2,192     693     490     347     245     219     155     127
"days"             91       29       20       14       10          9          6          5

max V (kms / sec) 4E+02 1E+03 2E+03 2E+03 4E+03 4E+03 6E+03 7E+03

This gives transit time for various accelerations, as well as the maximum velocity reached at turnover. Our trip to Iota Persei, from this earlier post and taking the actual FTL time as zero would take eight times the numbers above.  If we have a military-grade engine and remass tankage that can sustain 3Gs we can make the colony from Earth in about 40 days.  Slowboats had better freeze the cargo: at 1% of a G it will take 2 years.  This suggests that to have the scale of empire I want, even traders will need sustained boost capability over .2G, and the more the better.

It also means that if interstellar war (or even pirates) are a real threat we will need adequate local forces to deal with a threat and provincial governors with enough discretion to use them.


  1. Maybe look at the examples of the local governors in the Carribean during the 17th Century or the John Company (and its French and Dutch counterparts) in India. What would often happen is that there would be a very small garrison but they would employ privateers and locally raises militias/mercenary armies.

    Another thing that pops to mind in looking at this is the possible importance of where the jump/FTL points are. Is it anywhere beyond a certain limit or is it a specified region in space. If its a specific, relatively fixed place, its going ot make it both easier and harder for pirates to operate because then they know the routes since a merchant ship will want the most efficient route out of the spot to the destination.

    Just some thoughts.

  2. I certainly agree about taking liberally from history -- and from a number of different Imperial traditions.

    locally raises militias/mercenary armies.
    I think that will be particularly interesting when the local population is non-human.

    is the possible importance of where the jump/FTL points are

    I am looking forward to getting the software to the point where I can work those numbers. I plan to have a fairly large area where jumps can be made, so you don't get "mine-able' jump points. On the other hand I don't see piracy as something as ill-organized as say the Somali coast, but more the act of rogue governments and corporations with considerable resources and political clout.

  3. Well piracy for the most part has been ill-organized. It flourishes because centralized governments lack the ability, money, will, or all three to stamp it out. Although piracy along the Somali coast has been in the news over the last few years, there has been piracy in south-east Asia for a while that was problematic because of the jurisdictional problems.

    Also, different types of piracy flourish under different regimes. For example, the British were pretty organized about their piracy against the Spanish. These were essentially directed by the Crown with approved backers. They used it as a low intensity way of keeping the Spanish in check and filling the kingdom's coffers. Then there is the piracy of the Carribean. At first it was somewhat organized, but later became less so as more of the privateers became pirates. Buccaneers acted as a very interesting society where part of the time they would be hunters/herders and part of the time they would form ad hoc crews to go after a ship which strayed too close to the buccaneers territory. They were also remarkably egalitarian enterprises for the era.

    Have you decided whether there will be aliens? Sepoy units would be fascinating.

  4. I'm thinking of a fairly high density of aliens, including as full a range of technologies as I can balance with a active colonization by terrans. Sepoys would certainly be important, in all their variations. So would various forms of mercenary. If I needed to control a fractious alien population on a planet I wanted to exploit, and I had a more tractable population nearby, I might not bother to ship Humans from Earth, for example.