Listening for Extraterrestrial Blah Blah
If one is looking for signals from an extraterrestrial civilization, why not practice on some of the non-human communication systems already known on our own planet? Whales have had a global communication system for millions of years—longer than Homo sapiens has even existed. Bees, which communicate in part by dancing, had democratic debates about the best places to swarm millions of years before humans came up with democracy as a political system. And other examples abound. No person I know of who has studied another animal’s communication system has ever concluded that the species was dumber than they’d previously thought.
Through the study of animal communication, my colleagues and I have developed a new kind of detector, a “communication intelligence” filter, to determine whether a signal from space is from a technologically advanced civilization or not. Most previous SETI (Search for Extraterrestrial Intelligence) efforts have looked for radio transmissions with a narrow band of frequencies or for optical signals that blink very rapidly. From what we know about astrophysics, such transmissions would be clearly artificial, and their discovery would indicate technology capable of transmitting a signal over interstellar distances. SETI efforts generally throw away wideband radio signals and slower optical pulses, whose provenance is less obvious. Although those signals might well be from intelligent beings, they might also originate in natural sources of radio waves, such as interstellar gas clouds, and we
