Assuming our solar system’s newest interstellar object isn’t an alien mothership sent here to menace us, humankind still hasn’t spotted any signs of extraterrestrial life, let alone intelligence — which, given how incalculably vast the universe is, is strange. With all the potential homes for potential alien civilizations, why aren’t we seeing any evidence of them?
You’ve probably heard of the name for this conundrum: the Fermi Paradox. And you’ve probably heard of more than a few solutions to it, too.
There’s the infamous zoo hypothesis, which supposes that advanced aliens know about our planet but stay away to let us evolve naturally.
Or maybe you subscribe to spookier ones like the vulnerable worlds hypothesis, which holds that there may be a certain type of ominous technological innovation that humankind doesn’t even know about yet which always destroys any civilization advanced enough to develop it.
Or perhaps the universe is a kind of dark forest, with plenty of alien civilizations, but all too scared to show themselves out of fear of being annihilated by an even more advanced and bloodthirsty interstellar species.
But here comes the party pooper. In a new yet-to-be-peer-reviewed paper, NASA astrophysicist Robin Corbet proposes an outlook of “radical mundanity” that basically banishes these fun ideas back to the realm of speculative scifi. The Milky Way actually contains a modest amount of civilizations, according to this hypothesis, which was spotlighted by The Guardian — but the aliens aren’t busy tunneling wormholes or probing singularities. Instead, they’re only slightly more technologically advanced than we are, get bogged down by the same limitations when trying to look for fellow intelligent beings, and eventually give up on exploring the cosmos.
“The idea is that they’re more advanced, but not much more advanced. It’s like having an iPhone 42 rather than an iPhone 17,” Corbet, a senior research scientist at the University of Maryland, Baltimore County and NASA’s Goddard Space Flight Center, told the newspaper. “This feels more possible, more natural, because it’s not proposing anything very extreme.”
This mundane view explains why we aren’t seeing any technosignatures, or evidence of alien technology from afar. The aliens just don’t have what it takes to build huge megastructures that we could see with our telescopes, like a Dyson swarm that enshrouds a star to harvest its energy.
And while they might have the technological capability to travel to other stars, perhaps even with robotic probes, it’d be a painstakingly slow and enormously expensive undertaking, just like it would be for us. And so, finding no other civilizations along the way, they decide it’s not worth the cost. Ditto for powering a huge beacon for beaming a “we’re here!” signal out into the cosmos.
“They don’t have faster-than-light, they don’t have machines based on dark energy or dark matter, or black holes,” Corbet told The Guardian. “They’re not harnessing new laws of physics.”
It’s a sobering rebuff to some of our more fantastical theories of life in the cosmos. But not everyone’s a fan. Michael Garrett, the director of the Jodrell Bank Centre for Astrophysics, told The Guardian he liked the “fresh perspective,” but not much else.
“It projects a very human-like apathy on to the rest of the cosmos,” Garrett said. “I find it hard to believe that all intelligent life would be so uniformly dull.”
In fact, his personal hypothesis, detailed in a study accepted for publication in Acta Astronautica, couldn’t be more diametrically opposed to Corbet’s.
“I lean towards a more adventurous explanation of the Fermi paradox: that other, post-biological civilisations advance so rapidly that they slip beyond our capacity to perceive them,” Garrett told The Guardian. “I hope I’m right, but I could very well be wrong. Nature always has some kind of surprise for us around the corner.”
More on space: Scientist Says Galaxies Shining With Radio Signals Could Indicate Numerous Advanced Civilizations
