Trent Shipley wrote: > >> No. I propose that there are 2M planets _with_ galactic >> civilization settled on them. But they could be 20M or 200k. > > Good. So 2M is a _reasonable_ statistical expectiation for planets that > could support civilzation across 5 galaxies. > As a side note, Asimov's Galactic Empire includes 25M planets in a single Galaxy, all of them terraformed in the past 22,000 years. But Asimov was optimist about the existence of habitable planets, we know for sure that there can't be habitable planets around, for example, Epsilon Eridani, where Asimov placed Baleyworld-Comporellon.
>> Stars come and go, planets come and go. The terraforming of >> planets should probably just keep the number of planets in >> a stable number. > > Lets come back to terraforming. I think that it would be a major (and > s-l-o-w-l-y increasing) factor in the total number of habitable planets. > The key word here is _slowly_. For practical purposes, we can suppose that the number is more or less constant during the lifecycle of a standard species [1 million years] >> BTW, I also guess that there are about 10 fallow planets for >> each settled planet, based on the data that a planet is usually >> leased for 100ky, and it is let fallow for a minimum of 500ky >> [usually more]. > > I am going to assume that a factor of 1:10 is the high end for an inhabited > to fallow ratio if planets are leased for an average 100ky and fallow for a > minimum of 500ky. What we need is a figure for mean fallow time. Lets > pick 700ky. > > If there are 2M inhabited planets then there are 14M fallow planets. At > any given time there must be a total of 16M habitable planets. > Ok, 700ky, or 1My, don't change the final numbers very much Alberto Monteiro _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
