Over at Slate, Chris Wilson theorizes that we may not have detected any signals from extraterrestrial civilizations because of bad timing. Aliens transmissions could have reached our planet back when we were still wandering the plains of Africa. Similarly, any alien scientists situated a few hundred light-years away and pointing their radio telescopes at us right now would hear only silence. The universe is a really, really big place and there’s no guarantee that anyone will be around to listen to a whisper or a shout sent from across the stars. Perhaps civilizations across the universe have risen, flourished, and vanished over eons without ever detecting signs of other intelligence simply because they vanished just as the inhabitants of the nearest inhabited world were discovering the merits of fire. Perhaps we will have already faded into oblivion as a species by the time the denizens of Alpha Centauri broadcast their first anybody out there? into the depths of space.
