Science fiction has brought us so many concepts for colonizing the stars over the last hundred years, everything from interstellar arks loading thousands of colonists (the sea-faring metaphor) to worldships that see generations of crewmembers live and die during their long joiurney. Suspended animation can get people through a trip that takes centuries, while robotic wardens might oversee the safe passage of human genetic material that could be converted into a colony upon arrival.

von Neumann and ENIAC

If you want to be on the cutting edge today, though, better look toward what George Dvorsky talks about in Seven ways to control the Galaxy with self-replicating probes. Here’s a novel way to colonize a distant star system: Let a von Neumann probe find a promising planet and use the matter it finds there to establish a colony and fill it with settlers. Not the kind of settler that gets out of a suspended animation tank, yawns, stretches, and then walks out onto an alien landscape, but an uploaded consciousness that would be able to take physical (robotic) form to explore the new environment.

Image: John von Neumann, shown here with technology that might have been more to his taste, the 18,000 vacuum-tube strong ENIAC. One can only wonder what the sybaritic mathematician would have made of uploaded consciousness. If only he were here to tell us.

The awakening of a consciousness in an exoplanetary setting makes for still more science fiction fodder. And it’s an interesting take on where advances in computing might take us, one demanding artificial intelligence and supercomputing powers we may achieve sooner than we expect. The colony built with such methods could be quite large because it is limited solely by computational resources, and the von Neumann probe, with its assembler technology, can take care of that lack in short order. A single von Neumann probe using these methods spreads throughout the galaxy, offering strange new alternatives to travel. How about this:

Colonization probes could also construct data receivers and transmission stations so that uploaded persons could travel as digital data streams from one point to another. Consequently, the dream of traveling at the speed of light will some day be possible.

Traveling at the speed of light as a data stream gets you where you’re going with no perceived lapse of time (to you, at least), so that the journey to Andromeda is instantaneous. Which is quite enough to chew on, you would think, but Dvorsky’s fascinating article tackles the whole subject of von Neumann probes, breaking them down into categories ranging from explorer probes to berserkers, the ultimate in malevolent technology. All are intelligent devices capable of self-reproduction via molecular assemblers. You could put together a great science fiction reading list with treatments of all Dvorsky’s categories.

Ponder, for example, ‘uplift’ probes, most familiar through the work of Arthur C. Clarke and Stanley Kubrick in 2001: A Space Odyssey. The monoliths of the movie’s beginning enable the use of tools, an extraterrestrial civilization imparting gifts to the creatures it finds on a distant world, our own. Dvorsky also notes David Brin’s Uplift series and goes on to discuss motivations for uplift and its implications:

Uplift probes could quickly bring a civilization to a post-Singularity, postbiological condition. Such a force might appear as a colonization wave that sweeps across the Galaxy, transforming all that it touches into computronium. Such a scenario has been projected by such thinkers as Hans Moravec and Ray Kurzweil.

Computronium maximizes computing power to the point where we might imagine a Dyson sphere or a Matrioshka brain — a set of concentric Dyson spheres — created to capture usable energy from a star for use in computation. If species take such a route, and if galactic colonization via von Neumann probes could be accomplished in as little as half a million years (a reasonable extrapolation), then is the absence of the computronium ‘wave’ a sign that extraterrestrials aren’t out there? Or is it a sign (as Adam Crowl speculated to me in a recent e-mail) that the wave has already passed; i.e., the notion that we are already living in a simulation gains a delightful speculative force (I don’t believe it for a minute, but then, I’m not much an admirer of the Singularity either).

My own thinking on von Neumann probes is that self-replicating technology like this is best used in Dvorsky’s category two, the Bracewell probe. Ronald Bracewell imagined probes set up in an array of communications relays and Dvorsky points to the obvious cultural example in recent times, Sagan’s Contact, where a dormant Bracewell probe awakens in the Vega system and began to transmit to Earth after receiving radio evidence that a technological civilization is nearby. Bracewell probes in our own system? The most encouraging thing that can be said about the search for such is that there is no shortage of places to look. Stable orbits around Jupiter make a certain sense.