So I tweeted this in my Tweetmorrow incarnation:
The generation ship is a grand old sci-fi trope. The people on them are always forgetting they’re on one, which seems implausible to me but maybe that’s a subject for a more comprehensive post.
Generation ship yarns are fun and they’re a great walled garden to make stranger, more warped, and more insight-generating societies plausible than would otherwise be possible.
Which is probably why they’re usually depicted as small. Usually a few thousand or even hundred inhabitants.
Good for keeping stories simple. Not for generation-shipping.
For getting somewhere, you want BIG. I haven’t yet written a story around a jumbo generation ship, but I’ve mused and tweeted about it often enough. Hollow out Ceres. Take the Moon. Slap some magictech thrusters on Earth. From the sounds of it we could heat the surface with geothermal taps and keep it up for millions of years in the absence of a warming Sun.
I’m sure we could have Earth basking under a new star in five or ten thousand years. Not bad, really.
Wouldn’t it be funny if Earth ended up running away from the Solar System? We always imagine ships traveling from Earth, not BEING Earth.