Could there be a faster way to discover interesting galactic neighbors? Is there some scheme for detecting aliens that might work quicker than tuning in their radio transmissions or hunting down their laser pulses?
There might be, and for a simple reason. The cosmos is three times as old as Earth. During most of creation’s 14 billion year history, our solar system wasn’t around. Nonetheless, the early universe still had the right stuff for life, and contained worlds that were just as suitable for spawning biology and intelligence as our own.
Humans have existed only for the last 0.001 percent of cosmic time. All of which says that — unless the Homo sapiens brain is the one-and-only instance of cogitating machinery — nearly all the intelligence that’s out there is beyond our level.
And that intelligence is more than just a little bit beyond. Clearly, unless thinking beings inevitably wipe themselves out soon after developing technology, extraterrestrial intelligence could often be millions or billions of years in advance of us. We’re the galaxy’s noodling newbie’s.
That suggests an oft-overlooked approach to finding them. Advanced thinkers might be advanced tinkerers. Perhaps the really ambitious aliens have “disturbed the universe” (to use a phrase from British physicist Freeman Dyson) in ways that are directly visible.
This disturbance might take the form of deliberate engineering, such as the construction of mammoth artificial structures. Perhaps they’ve rearranged some stars into easily recognizable patterns. Maybe there’s left-over debris from massively destructive wars. You can consult science fiction for other examples of what an enormously advanced society might have strewn about. It’s as good a predictor as any, because obviously we don’t know.
Indeed, the fact that we can’t easily foresee clues that would betray an intelligence a million millennia farther down the road suggests that we’re like ants trying to discover humans. Ask yourself: Would ants ever recognize houses, cars, or fire hydrants as the work of advanced biology? - Seth Shostak