SETI may have a hard time finding anything at all, even if the universe is teeming with life. This article, which I picked up over at PhysOrg, cites new research which says that once you get good at compressing your data, radio transmissions become indistinguishable from those naturally emanating from stars. SETI looks for inefficient transmissions like the ones we currently create, but it’s likely that any civilizations out there who have had radio for more than the paltry 8 decades we have will be communicating in very efficient, compressed code.
Bummer. We’re probably staring at hundreds of really, really cool feeds from 20,000-year-old disc jockeys when we look at the night sky, but our gear doesn’t recognize the signal. (And we don’t have their public key, either.)