Are we alone in the universe? The question has been debated by stargazers since, well, since we’ve been able to look up and gaze at the stars. Scientists, theologians, and science fiction writers alike have all pondered whether life exists on one of those distant stars that light up the night sky.
Mathematically, it seems almost certain that life must exist somewhere. Astronomers estimate there are 100-200 billion galaxies in the universe. The Milky Way galaxy alone is home to an estimated 100-400 billion stars, and if we multiply that by the estimated age of the universe (14 billion years), carry the one…and that’s a lot of opportunity for life to sprout up.
In 1950, Italian-American physicist Enrico Fermi was having lunch with colleagues who were discussing the near mathematical certainty that other life must surely exist in the infinite universe. After a beat, Fermi interrupted the group with a simple question: "Then where is everybody?" That question, now known as Fermi's Paradox, has been challenging brilliant thinkers ever since.
If someone else is out there, why can't we hear them? Why would all of them hide from us all this time? It begs the question: Are we alone after all?
Not every astronomer is convinced that life is actually out there. A team of NASA scientists is revisiting Fermi's Paradox with new eyes, and a new theory which posits that we are indeed alone in the universe... because everyone else destroyed themselves.
And they think we’re on the same trajectory.
The Great Filter
A team from NASA’s Jet Propulsion Laboratory is discussing this “Great Filter” theory in search of an explanation for why we have yet to make contact with intelligent life out there in the universe. It’s estimated that there are potentially trillions of life-supporting planets out there, so why haven’t any of them given us a visit?
The short answer is, whatever civilizations existed out there in the murky blackness of space died out before they could ever contact us. As the theory posits, entire alien species - with their own economies, cultures, and faiths - evolved, lived, and then perished before they could ever find us.
The scary part is, the NASA team reviewing this theory suggests that these civilizations weren’t wiped out by a stray meteor or an attack from other space faring species. Rather, they inflicted the wounds upon themselves.
War, famine, irreversible climate change, pandemics, rampant income inequality, artificial intelligence, you name it – the very same crises we face today are speculated to be the causes of who knows how many civilizations that came before us.
Turns out, once a species becomes intelligent enough, it becomes its own worst enemy. And the team at NASA says we’re potentially on the same track.
“Human civilization over the past 5000+ years, and in particular since 1945, has revealed much of what would surely impede, if not outright arrest, our aspirations to colonize other worlds in the Solar System and beyond,” writes the NASA team in a paper titled “Avoiding the ‘Great Filter’”.
“It seems as though nearly every great discovery or invention, while pushing back the borders of our technological ignorance, is all too quickly and easily turned to destructive ends. Examples such as splitting the atom, biomedical innovations and resource extraction and consumption come to mind with disconcerting swiftness.”
They say that if we’re going to avoid the fate that befell civilizations before us, we must work together to identify and solve these problems. “The key to humanity successfully traversing such a universal filter is found in understanding what characteristics the barrier will constrain, identifying those attributes in ourselves and neutralizing them in advance,” they write.
While the outlook is grim, they say all hope is not lost. If we can shed our “immaturity” and unite towards saving our planet, we may just make it yet.
What do you think? Are alien civilizations real, and if so, have they actually already killed themselves off? And if so, how can we avoid that same fate?