In 2010, Scientific American reported on SETI. They predict that in a couple of decades we’ll have scanned tens of millions of stars; enough for a decent chance at detecting a radio signal, if there is any to find. But they make an unwarranted assumption; that emission of radio signals would be evidence of a technological civilization.
I beg to differ. It would be evidence of life, of radio-using life at that, but not necessarily evidence of technological civilization, or even intelligence.
Our own planet has many animals with high tech. For instance: electric eels with an electromagnetic sense; bats and cetaceans with sonar; and birds with magnetic compasses. So I speculate that there may be, on distant worlds, living beings who can send and receive radio, for radar and for communication, but who do not possess higher intelligence or technological civilization. I nickname such beasties “Radar Bats”. They could have evolved in Darwinian fashion, or they could be left-over biotech relics of a civilization now extinct; in either case, radar bats could fill the sky of a world devoid of higher intelligence.
So if we ever got complex signals from a distant world, there’d be two explanations, not one; Intelligent Beings and Radar Bats. How to tell the difference? Perhaps by the content. It’s hard to predict what a truly intelligent being would transmit. An epic poem in praise of the beauty of the universe, perhaps; or a chapter of the Encyclopedia Galactica; or a proof of Reinmann’s Hypothesis encoded in a symphony. Who knows? But it’s easy to predict what radar bats would fill the airwaves with: brags, threats, territorial claims, status challenges, mating cries, courtship rites, warning signals and swarming calls.
With this in mind, I have investigated our own planet’s radio emissions. There I have discovered many brags, threats, territorial claims, status challenges, mating cries, courtship rites, warning signals and swarming calls; but no cosmic poetry, nor a single page from the Encyclopedia Galactica, nor a single note of the Reinmann Symphony.
Therefore radio observations have yet to detect intelligent life on planet Earth.