The recent discovery of an Earth-like planet that may harbor life got me to thinking about interstellar space travel. While reading about that, I stumbled upon an article by Seth Shostak, who says we should be looking for machine intelligences, not conventional lifeforms. This, he thinks, would change where we look, at the very least. He made a point that I thought was quite striking:
So he sees a Singularity as inevitable for any advanced society. Further, while we lived as hunter-gatherers for hundreds of thousands or millions of years, depending on what you want to consider "us", we've only had any reasonable sense of the cosmos within the past century, and will very likely have reached the Singularity within the next. This means that the period of technologically advanced life that we now inhabit is a vanishingly small fraction of our total history as a species, particularly if our machine progeny are considered to be somehow "us". Since we want to continue living and having fun, it's likely that some of them will in fact contain our consciousnesses, so it seems reasonable to consider at least those machines to be "us".“Once any society invents the technology that could put them in touch with the cosmos, they are at most only a few hundred years away from changing their own paradigm of sentience to artificial intelligence.”