This is not to say that interstellar travel is impossible; quite the contrary. But to do so effectively you need either (a) outrageous amounts of cheap energy, or (b) highly efficient robot probes, or (c) a magic wand. And in the absence of (c) you're not going to get any news back from the other end in less than decades. Even if (a) is achievable, or by means of (b) we can send self-replicating factories and have them turn distant solar systems into hives of industry, and more speculatively find some way to transmit human beings there, they are going to have zero net economic impact on our circumstances (except insofar as sending them out costs us money).I recommend that you read article; there's lots to consider.
That said, I agree with Stross that space colonization is not in our future -- or anybody's future for that matter. But I disagree with him as to why this is the case (this is largely what I'll be speaking about at TransVision 2007 next month).
First, Stross's analysis fails to take into account future civilization types; I get the sense that he takes a normative view of today's technological and economic realities and projects them into the future. This is surprising, not only because he's an outstanding science fiction visionary, but also because he's a transhumanist who has a very good grasp on what awaits humanity in the future (in fact, he was the WTA's transhumanist of the year for 2004). Specifically, he should be taking into account the possibility of post-Singularity, Drexlerian, Kardashev Type II civilizations. Essentially, we're talking about post-scarcity civilizations with access to molecular assembling nanotechnology, radically advanced materials, artificial superintelligence, and access to most of the energy available in the solar system.
Stross also too easily dismisses how machine intelligences, uploaded entities and AGI will impact on how space could be colonized. He speculates about biological humans being sent from solar system to solar system, and complains of the psychological and social hardships that could be inflicted on an individual or crew. He even speculates about the presence of extraterrestrial pathogens that undoubtedly awaits our daring explorers. This is a highly unlikely scenario. Biological humans will have no role to play in space. Instead, this work will be done by robots and quite possibly cyborgs (which is how the term 'cyborg' came to exist in the first place).
Stross does mention the possibility of probes being sent out, but again, fails to account for the economic benefits of self-replicating probes. He notes the extreme distances involved in space travel -- another way of saying that it takes too long. Given the alternative mind-space and clock-space that a machine mind could inhabit, time is not a very helpful variable when discussing the limitations of space travel.
Spacecraft propulsion was another topic that Stross addressed. My feeling is that he should have spent more time analyzing some of the more radical possibilities for star-to-star space travel. I'm fairly convinced this is not an inhibitor to space colonization.
Finally, Stross's analysis invokes far too much sociology and rationalization. Cost and time scales aside, he did not take into account the drive for scientific advancement and exploration. The search for life on other planets is a rather important one -- it's a mystery we seem rather hell-bent on solving. Moreover, it's difficult to predict what private individuals or groups may do on their own. I can totally imagine an eccentric and motivated crew that organizes a mission into space.
As for my own arguments against space colonization, like I said, that's the topic I'll be addressing at TV07. Stay tuned for more over the coming weeks.