If and when we finally encounter aliens, they probably won't look like little green men, or spiny insectoids. It's likely they won't be biological creatures at all, but rather, advanced robots that outstrip our intelligence in every conceivable way. While scores of philosophers, scientists and futurists have prophesied the rise of artificial intelligence and the impending singularity, most have restricted their predictions to Earth. Fewer thinkers?"outside the realm of science fiction, that is?"have considered the notion that artificial intelligence is already out there, and has been for eons.