Humans have always been fascinated by the idea of space travel. Some even believe that colonizing new planets is man’s best hope for the future. The popular idea is that we’ll eventually need some fresh, unexploited new worlds to inhabit -a real-world Pandora.
In an earlier Galaxy post we wrote that Stephen Hawking, world-celebrated expert on the cosmological theories of gravity and black holes who held Issac Newton's Lucasian Chair at Cambridge University until his recent retirement, believes that traveling into space is the only way humans will be able to survive in the long-term, while warning about the potential threat of actual alien contact with Earth.
"Life on Earth," Hawking has said, "is at the ever-increasing risk of being wiped out by a disaster such as sudden global warming, nuclear war, a genetically engineered virus or other dangers ... I think the human race has no future if it doesn't go into space."
Another of his famous quotes reiterates his position that we need to get off the planet relatively soon. "I don't think the human race will survive the next 1,000 years unless we spread into space."
The problems with Hawking’s solution is that while it may save a “seed” of human life- a few lucky specimens- it won’t save Earth’s inhabitants. The majority of Earthlings would surely be left behind on a planet increasingly unfit for life.
In a futuristic mode similar to Hawking, both Steven Dick, chief NASA historian and Carnegie-Mellon robotics pundit, Hans Moravec, believe that human biological evolution is but a passing phase: the future of mankind will be as vastly evolved sentient machines capable of self-replicating and exploring the farthest reaches of the Universe programmed with instructions on how to recreate earth life and humans to target stars.
Dick believes that if there is a flaw in the logic of the Fermi Paradox, and extraterrestrials are a natural outcome of cosmic evolution, then cultural evolution may have resulted in a post-biological universe in which machines are the predominant intelligence.
Renowned science-fiction writer, Charlie Stross, argued last week in his High Frontier Redux blog that space colonization is not in our future, not because it's impossible, but because to do so effectively you need either outrageous amounts of cheap energy, highly efficient robot probes, or "a magic wand."
"I'm going to take it as read that the idea of space colonization isn't unfamiliar," Stross opens his post, "domed cities on Mars, orbiting cylindrical space habitats a la J. D. Bernal or Gerard K. O'Neill, that sort of thing. Generation ships that take hundreds of years to ferry colonists out to other star systems where — as we are now discovering — there are profusions of planets to explore."
"The obstacles facing us are immense distance and time -the scale factor involved in space travel is strongly counter-intuitive."
Stross adds that "Planets that are already habitable insofar as they orbit inside the habitable zone of their star, possess free oxygen in their atmosphere, and have a mass, surface gravity and escape velocity that are not too forbidding, are likely to be somewhat rarer. (And if there is free oxygen in the atmosphere on a planet, that implies something else — the presence of pre-existing photosynthetic life, a carbon cycle, and a bunch of other stuff that could well unleash a big can of whoop-ass on an unprimed human immune system."
Stross sums up by saying that while "I won't rule out the possibility of such seemingly-magical technology appearing at some time in the future in the absence of technology indistinguishable from magic that, interstellar travel for human beings even in the comfort of our own Solar System is near-as-dammit a non-starter."
Stross's blog received over 450 comments as of this writing. The most prescient follows:
"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. 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)."