We might be alone in the universe and a new NASA theory explains why

The climate crisis on Earth "may explain the cosmic silence," a group of NASA scientists explains.
Chris Young
A dead and barren world in the space
A dead and barren world in space


Alien civilizations may have slowly wiped themselves out due to climate catastrophes on their home planets.

In a new paper published in the pre-print server ArXiv, a group of NASA scientists analyzed the 'Great Filter' theory, which posits that ancient alien civilizations may have wiped themselves out before they had any chance of making contact with humanity.

The new study serves as a warning for our civilization and paints a picture of a universe that has been home to many civilizations, precious few of which, if any, have lasted long enough to become interplanetary species.

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The 'Great Filter' theory serves as a timely warning for our society, as it shows an outside perspective on how entire civilizations may have slowly created the conditions leading to their own demise.

The Great Filter theory is also a possible answer to the Fermi Paradox, which states that intelligent alien life should be abundant and detectable, given the fact that there are billions of planets located within the habitable zones of their solar systems in our galaxy alone.

The paper states that "evidence of life should exist in abundance in our galaxy alone, and yet in practice, we’ve produced no clear affirmation of anything beyond our own planet. So, where is everybody?"

"We postulate that an existential disaster may lay in wait as our society advances exponentially towards space exploration, acting as the Great Filter: a phenomenon that wipes out civilizations before they can encounter each other, which may explain the cosmic silence."

The new study, which has yet to be peer-reviewed, suggests that humanity will have to raise its self-awareness levels to overcome the climate crisis. "The key to humanity successfully traversing such a universal filter is... identifying those attributes in ourselves and neutralizing them in advance," the study's authors explain.

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Essentially, the paper's authors suggest that any existential threats we face here on Earth — including climate change, nuclear war, pandemics, and other factors — have likely been faced countless times by other civilizations over millions of years throughout the universe.

Humanity should strive "towards the highest peaks of invention"

The Great Filter theory was first proposed in 1998 by Robin Hanson, an economist at George Mason University. In an essay at the time, he wrote that "the fact that our universe seems basically dead suggests that it is very, very hard for advanced, explosive, lasting life to arise."

Hanson suggested that many alien civilizations may have evolved to a point before they had the technology required to expand off-world, only to have then been wiped out.

In their new paper, the NASA scientists state that human civilization must evolve so as not to succumb to the 'Great Filter'. "History has shown that intraspecies competition and, more importantly, collaboration, has led us towards the highest peaks of invention," the paper reads, "And yet, we prolong notions that seem to be the antithesis of long-term sustainable growth. Racism, genocide, inequity, sabotage... the list sprawls."

While the Great Filter theory is an important thought experiment in the face of challenges we face here on Earth, some scientists do argue that it doesn't factor in our current limited capacity to view the cosmos.

In an interview with The Daily Beast, Seth Shostak, a California-based astronomer with the SETI Institute, said, "The Great Filter theory depends on the assumed observational result that nobody is out there. But that conclusion is far too premature. We've just begun to search."

Still, the new paper serves as a stark warning for humanity, at the same time shining a light on the fact that human collaboration can play a vital role in improving our chances of survival against the many existential threats our species could face in the coming years.

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