More and more astronomers are coming to the conclusion that we are not alone in the universe. For them, it’s a matter of math and humility. With potentially trillions of life-supporting planets out there, why should ours be the only one to have developed a high-tech civilization?
But as aliens to do exist, we still haven’t met them. (Probably.) You’d think that out of trillions of chances for life to spawn in the universe, we’d have found signs of other intelligent life, right?
Now a team at NASA’s Jet Propulsion Laboratory in California is revising an old theory to explain Why. The “Great Filter” theory states that other civilizations, possibly many, have existed during the history of the universe, but they all wiped themselves out before they had a chance to contact us.
Even more chilling, we’re on track to “filter” ourselves out of existence, so to speak. In that sense, understanding why we didn’t meet other civilizations – that is, what aliens may have done to self-destruct – could hold the key to saving our own civilization.
“The key to successfully traversing such a universal filter for humanity is … identifying those attributes in ourselves and neutralizing them beforehand,” JPL astrophysicist Jonathan Jiang and his co-authors wrote in a new study that appeared online on October 23 and has not yet been reviewed.
Not everyone in the sciences buys the idea of the Great Filter. “It feels overly deterministic, like the Great Filter is a physical law or a single looming force that confronts every emerging technological civilization,” Wade Roush, a science teacher and author of aliens, told The Daily Beast. “We have no direct evidence of such power.”
But the impact of the theory is undeniable. The Great Filter was originally proposed by Robin Hanson, an economist at George Mason University, in 1996. Since then, it has become a staple of science fiction world-building. And for good reason: it is dramatic. “The fact that our universe appears to be essentially dead suggests that it is very, very difficult to create advanced, explosive, sustainable life,” Hanson wrote.
By ‘explosive’ he refers to the possibility that a civilization will quickly realize cheap space flights and colonize many other planets. In Hanson’s theory, there is something – or a lot – that prevents intelligent life from thriving on its home planet, expanding to other planets, and surviving long enough to make contact with aliens like us.
At least one leading proponent of the search for extraterrestrial life has no objection to the theory. “I think it’s plausible,” Avi Loeb, a Harvard physicist, told The Daily Beast.
To understand the Great Filter, Jiang and his co-authors looked at humanity in a mirror. What is most likely to kill U.S power also pose an existential threat to intelligent life on other planets, they suggested. They compiled a short list of the greatest threats to the human species, all but one of our own fault.
Of course, an asteroid can hit Earth with enough force to kill just about anything on the planet. That’s not necessarily something we can avoid. But the other civilization killers the JPL team thinks probably are too self-inflicted. Nuclear war. Pandemic. Climate change. Runaway artificial intelligence.
Jiang’s team attributes these existential risks to what they describe as deep-seated dysfunction in intelligent beings such as humans. “Disfunction can quickly snowball into the Great Filter,” the researchers wrote.
But dysfunction is not inevitable, Jiang and his co-authors emphasized. “The basis for many of our possible filters stems from immaturity,” they wrote. We could grow up as a species, dismantle our nuclear weapons, switch to clean energy, fight the zoonotic viruses that cause the worst pandemics, and even develop better technology to fend off planet-killing asteroids.
All these reforms require humanity to work together, the JPL team wrote: “History has shown that interspecies competition and, most importantly, cooperation has led us to the highest pinnacles of invention. And yet we are prolonging notions that seem to be the antithesis of long-term sustainable growth. Racism, genocide, inequality, sabotage… the list is growing.”
With peace, love and understanding – and some major technological breakthroughs – we may be able to survive our own self-destructive tendencies and defy the Great Filter. And if we can work together to get past the filter, that goes without saying other civilizations could also. Our own survival should give us hope that one day, somehow, we will meet the other survivors of the Great Filter.
Or maybe not. Hanson himself thinks Jiang and his company have the Great Filter, and its possible solutions, in part wrong.
The global partnership that Jiang and his company advocated as a means of survival could be the very thing that will eventually destroy us, Hanson told The Daily Beast. “Clearly they are recommending more centralized control and governance of our civilization,” Hanson said. “But I actually see over-centralization of governance as the most likely contributor to our future Great Filter.”
In Hanson’s view, the more we decentralize, the more likely some of us will survive and thrive. Imagine isolated farmers going through a devastating pandemic, or private space explorers – your Jeff Bezoses and Elon Musks of the world – establishing alien colonies on the moon or Mars. Colonies that could last even if disaster wipes out everyone on Earth.
Other critics think the whole Great Filter theory is nonsense. It’s possible we haven’t met aliens yet, not because they’re all dead, but because… well, we haven’t met them yet. The universe is huge. Even if there are billions from thriving alien civilizations, they are almost certainly very far away. It will take patience and a lot of searching to eventually find them.
“The Great Filter theory depends on the supposed observation result that there is none,” Seth Shostak, an astronomer at the California-based SETI Institute, told The Daily Beast. But that conclusion is far too premature. We have just started searching.”