Stephen Hawking is advocating human colonization of space, and the eventual colonization of other star systems. That’s not the right way to think, says P.Z. Myers on Pharyngula. Colonization doesn’t help most of the human race, who would be stuck on Earth anyway no matter what.
I’m both less and more pessimistic than Chris about the possibilities, though. I think there is a path to accomplishing expansion to other worlds, but it is indirect. The first priority is to put our own house in order: we need stable, sustainable human cultures that know how to maintain a healthy environment (if we can’t prevent ourselves from trashing a whole planet, how are we going to ever maintain a viable home in the more limited and hostile confines of a habitat elsewhere?). Given that opium dream, I could see a pattern of evolving technology and careful exploration leading to the gradual establishment of some kind of humanity elsewhere. Not as an ‘escape’, of course, but because life, like cockroaches, expands to the limit of its ability.
Then P.Z. brings up the possibility of a speciation event if colonization happens — restricted gene pools with miniscule gene exchange with the parent population provides an excellent opportunity for that.
I think the caveats on who benefits from space colonization are good to bear in mind. I think that getting humans living their lives off-planet will happen when the conditions for colonization are right. That is, when the same conditions apply to the frontier of space that have applied to the other frontiers that people have dealt with in history: there is an economic benefit to the colonial milieu. As P.Z. notes, we’re not there yet with space. What few things are possible to do in space and not on Earth are not yet full compensations for the other expenses of human life outside the protective confines of our home biosphere.
This should not mean that we neglect research into technologies that will be useful for operations in space, including those technologies that will permit the efficient collection of resources needed for making habitats either self-sustaining or close to it. Somewhere packed away I’ve got a batch of NASA-sponsored papers detailing work on “closed environmental life support systems” (CELSS). I kind of like the mention of cockroaches on Pharyngula, for one of the ideas examined in CELSS studies is the use of insects as an efficient way to convert grains into protein. I don’t recall that cockroaches were mentioned specifically, but I seem to recall crickets being mentioned with favor. Don’t expect a Tang-like spinoff technology to take off on terra firma anytime soon, but there is a point there. I recall my falconry sponsor at one of our hawking meets demonstrating how to find tasty beetle grubs under the bark of fallen trees. (That isn’t a falconry thing; he was an entomologist.)
As technology expands, there may be some benefit to constructing and operating certain facilities off of Earth. I recall a placatory article in Physics Today a few years back explaining why the various doomsday scenarios proposed as possible outcomes of experiments at Brookhaven’s Relativistic Heavy Ion Collider were unlikely to actually happen. I also recall thinking that for myself, ignorance was somewhat more blissful than thinking about voracious strangelets, lower energy states of vacuum, and incidental black hole production. Some things would still be a problem for facilities located elsewhere, but still in our universe, but at least some items would be less of a problem if they weren’t right in our backyard, as it were.
And I wonder if use of space may not continue to reap benefits for trying to maintain our terrestrial ecosphere. We don’t need humans in space to benefit from programs like LandSat and the like, but perhaps we will develop technologies that need more than a token human presence on site to operate.
One thing that I don’t recall being broached is that the entertainment industry is pretty close to having budgets that would make the use of space a possibility for them. It would be rather ironic if space as a frontier were opened up with “Disney Solar System” and an explosion of cheap knock-off entertainment facilities popping up nearby. Space might even turn out to be more hospitable to the Disney Corp bottom line than France was.