Estimated reading time — 2 minutes
As astronomers began to dig deeper into the cosmos, a puzzling question arose. In a universe as vast and ancient as our own, why can’t we find any signs of other intelligent life? We have already discovered a number of Earth-like planets, and it’s estimated that there are thousands if not millions of planets throughout the galaxy that could support life as we know it. Presumably, at least a few would give rise to advanced alien civilizations, and we should be able to detect such civilizations by listening for radio signals that are too complex and organized to be of natural origin. After all, anyone within 100 light-years of the sun could detect us through the broadcasts emanating from Earth, so why couldn’t it work the other way around?
Yet whenever we listen for these signals, we only hear silence. There is nothing. Nothing but the chaotic emissions of pulsars, gamma ray bursters, and other natural sources.
Scientists refer to this as the Fermi Paradox. Given the seeming statistical certainty there being alien civilizations, why can’t we find any? Why do we seem to be so special? It wouldn’t be a matter of signals fading over distance – we can detect the faint glow of galaxies millions of light-years away that have long since ceased to exist. There have been a number of proposed explanations. Maybe Earth truly is unique after all. Maybe aliens don’t use radio waves.
However, some scientists fear a different possibility. Perhaps advanced civilizations invariably destroy themselves before being able to broadcast for any meaningful amount of time. It could be nuclear war, or it could be an environmental catastrophe. Whatever it is, this theory speculates, within a couple short centuries of becoming advanced enough to harness radio waves, intelligent life is doomed to obliterate itself. The window of time during which it could send – and receive – radio broadcasts is but a blink of the eye on a cosmic timeframe, and if the signals arrived at the world of another intelligent species, it would likely be too early, or too late.
If this is true, humanity is simply another iteration in an infinite cycle of doomed civilizations that repeats itself all across the cosmos. Despite all our achievements and accomplishments, we will all die a painful collective death, perhaps within our lifetime. And just as we are unaware of our alien predecessors on distant worlds, future intelligent life on a system but 20 light years away will never know we even existed. Who knows? We tried sending targeted broadcasts to various star clusters, but perhaps others did the same. We’ve tried securing a form of symbolic immortality by sending probes carrying our life story into interstellar space, but perhaps the universe is littered with such mementos to dead races, all launched in the same, vain hope of being remembered by the cosmos. Why would we be so special?
Of course, this proposal could be false. There is no real scientific evidence either way. It is all an intellectual parlor game for astronomers, right? Perhaps. But the next time you read about climate change, the next time you learn about how close we have come to the brink of nuclear war at times, the next time you hear about an emerging crisis with North Korea or Iran…
Look up at the stars, and remember the Fermi Paradox…
Credit To – W. H. Lane