We all need one now and again. So here’s a young Carl Sagan, in his pre-turtleneck days, talking about aliens visiting us:
A bunch of years ago, I got into a long rolling email conversation with some friends, trying to establish how we felt about the Drake Equation and Fermi’s Paradox. It seemed to me at that time that a low-effort take on the whole thing is to shrug at the Drake Equation and say “sure, it shows there are probably loads of alien civilizations out there.” And the answer to Fermi’s Paradox is also a shrug: it turns out that getting up to relativistic speeds is elusive and all of the alien civilizations, like us, are stuck like flies in amber in their local regions of space. The macguffin of “hyperspace drive” or “wormhole drive” or whatever features prominently in the alien civilizations’ science fiction book sections – just like it does in ours – but it staunchly remains science fiction and every civilization winds up slamming face first into the problems of the high frontier, which cannot be overcome, and they eventually either die struggling or become stoics and die quietly. It’s all very well and good to imagine signalling aliens by banging a couple of black holes together, or whatever, but it just doesn’t happen.
My theory is that civilizations arise, build their equivalent of a Hubble Space Telescope, take a good look around, think about it, refine their theories, and then say “Well, that’s it. We’re stuck here. Phooey.”
Science fiction ideas that there will always be newer, better tech, are for folks like Ray Kurtzweil – who seem to assume that just because humans are pretty clever that we will eventually become infinitely clever. That there is no limit to how far we can evolve our technology. That’s a neat daydream but if you look at the way we’re swirling down the drain of fossil fuels and overpopulation, I don’t see any reason for unbounded optimism. We’re getting to the point where we understand how batteries work and are bumping up against theoretical limits there. We understand how chemical rockets work and we are bumping up against theoretical limits there, too. We understand how to make fusion and are bumping up against limits there. Maybe not all limits can be overcome through enough hard work. What if it’s an actual hard limit? Expanding into our solar system may be too hard for us. Sure, “we’ve got to.” But that doesn’t mean we can.
Charles Stross has a really interesting thread on this stuff over at his blog [stross] and inevitably there’s Kim Stanley Robinson’s Our Generation Ships Will Sink [boing] We can optimize a bit like leaving the testicles at home[stderr], but we need everything to be vastly better than it is for any of this stuff to become anything like practical.