Bjork's colonization simulation does not explain Fermi's Paradox

A number of science sites are proclaiming that the Fermi Paradox may have been solved by Rasmus Bjork, a physicist at the Niels Bohr institute in Copenhagen. Unfortunately, his claim does not withstand scrutiny; the Fermi conundrum is still far from being answered.

Bjork is making a point that many others have made before, that ETI's have not had enough time to colonize the Milky Way. What makes his claim different, however, is that he used a computer to simulate the migrational spread of intergalactic probes.

In his simulation, Bjork had a single civilization launch 8 intergalactic probes to search for intelligent life. Once on their way, each probe would send out eight more mini-probes to search for the nearest stars and look for habitable planets. He was careful to set the parameters such that the probes would only investigate the galactic habitable zone of the Galaxy. Bjork also set it up such that the probes could travel at 30,000km/second, or a tenth of the speed of light.

Based on these settings, Bjork discovered that it would take these probes 10Gyr to explore a measly 4% the Galaxy -- roughly half the age of the Universe. This data would indicate that there most certainly has not been enough time for ETI's to thoroughly explore the Milky Way.

His analysis, however, fails to take into account the likely nature of intergalactic exploration and colonization. In Bjork's simulation, he tracks the progress of a mere 72 probes. Given this ludicrously limited strategy, it would take these 8 primary probes and 64 sub-probes 100,000 years to explore a region of space containing 40,000 stars. Such an effort would almost certainly be considered futile by any civilization, and it's doubtful any ETI would embark on such a project.

Instead, what Bjork should have considered is the potential for ETI's to proliferate Von Neumann replicating probes. Advanced civilizations with access to molecular assembling nanotechnology would be capable of launching self-replicating probes. Initially, the spread of Von Neumann probes would be slow, but like any exponential process, progress would eventually explode. It's been estimated that these types of probes could reach all four corners of the Galaxy anywhere from 5 to 50 million years. That's a far cry from Bjork's projected 250Gyr.

So, no, the Fermi Paradox has not been solved. Far from. And it's high time that cosmologists and astrobiologists stopped using technology from Star Trek to inform their research.