March 07, 2008
On the Killing of Worlds
Sentient Developments: Seven ways to control the Galaxy with self-replicating probes discusses one of my favorite subject: self-replicating machines. IMHO there is no more powerful technology around. If you have something growing exponentially it will outdo everything else in the long run. Combine that with interstellar travel and you can remake the galaxy.
Which might be a problem. Because it is quite feasible to make killer probes, "berserkers". I'm finishing up a paper on the technology and ethics of berserkers. Here is the title and abstract I used when holding a seminar about it a while ago:
On the Killing of Worlds: The Fermi Paradox, Self-Replicating Machines and Interstellar Arms Races
Abstract: The Fermi Paradox is the apparent contradiction between a large, old universe where numerous species of intelligent life could have evolved and the lack of evidence for such beings. Various attempts at resolving it have been made. One category of resolution that has not been studied much is the possibility that the lack of intelligent life might be due to it being killed off by something external. A good candidate for this kind of external threat is self-replicating interstellar probes originally launched by some species. I demonstrate that the technological demands for making a device that can travel interstellar distances, build copies of itself and detect and destroy planetary civilizations are relatively modest and likely could be fulfilled within this century. However, the efficiency of attacking a species distributed over interplanetary or interstellar distances is much lower. This places hard constraints on the dispersal and readiness to attack for such devices if they are to be workable explanations of the Fermi Paradox. Our own continued existence on the other hand contradicts these abilities: either we have been very lucky, or (with high probability) there currently does not exist any hostile replicators. However, it might be rational for any civilization to launch “police devices” to proactively stop hostile replicators, leading to the possibility of interstellar arms races.