For decades, the question of whether humanity is alone in the universe has haunted scientists, philosophers, and the simply curious alike. Despite the hundreds of billions of planets scattered across the Milky Way, our search for intelligent extraterrestrial life has yielded little more than cosmic silence. Now, a new theory, proposed by Dr Robin Corbet—senior research scientist at NASA's Goddard Space Flight Center and the University of Maryland, Baltimore County—offers a refreshingly down-to-earth explanation for this enduring mystery.
On October 15, 2025, Dr Corbet unveiled his theory of "radical mundanity," which seeks to unravel the so-called Fermi paradox: the puzzling contradiction between the high probability of alien civilizations existing and our total lack of evidence for them. Rather than hypothesizing about super-advanced aliens zipping around the galaxy or hiding behind some cosmic "do not disturb" sign, Corbet suggests that extraterrestrial civilizations (ETCs) are actually quite a bit like us—technologically speaking, anyway.
According to Dr Corbet, there are likely a modest number of ETCs in the Milky Way. But, as he wrote in his paper "A Less Terrifying Universe? Mundanity as an Explanation for the Fermi Paradox," none have achieved the kind of technology needed for large-scale astro-engineering feats or the motivation to send out high-powered beacons for millions or even billions of years. "This consideration also leads to the expectation that no ETC will colonise a large fraction of the Galaxy, even using robotic probes, and that there are no long-duration high-power beacons," Corbet explained.
Why would that be? The answer, Corbet argues, is simple: the energetic and temporal costs of trying to communicate across the vastness of space are astronomical. Sending out a beacon powerful enough to be noticed—or launching probes to other stars—would require an immense commitment of resources, with the likelihood of a reply so delayed it might take millions or even billions of years. In short, it's not a very enticing prospect for civilizations that, much like us, have limited time and energy to spare.
Corbet even speculates that Earth itself is "not likely to be a very interesting place to visit," at least from the perspective of these hypothetical neighbors. If there are a reasonable number of ETCs in the galaxy, he suggests, the motivation to reach out and make contact simply isn't there. Instead, they may have explored their own cosmic backyards for a while, gotten bored with the results, and decided to focus their attention elsewhere.
"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 told The Guardian. "This feels more possible, more natural, because it's not proposing anything very extreme." In other words, if we ever do make contact with alien life, we shouldn't expect to be dazzled by mind-bending technology or physics-defying machines. Corbet insists, "They don't have faster-than-light, they don't have machines based on dark energy or dark matter, or black holes. They're not harnessing new laws of physics."
This principle of radical mundanity also has a calming side effect: it all but eliminates the likelihood of a hostile alien invasion. Without the technological means or motivation to cross the galaxy, ETCs would have little reason—or ability—to threaten Earth. For those who have worried about the specter of extraterrestrial conquest, that's one less thing to lose sleep over.
Corbet's theory stands in contrast to some of the more exotic explanations for the Fermi paradox that have been floated over the years. Some have suggested that Earth is part of a "celestial zoo," deliberately left undisturbed by more advanced civilizations. Others have speculated that aliens have transcended their physical forms or discovered laws of physics that make them undetectable. Corbet, however, finds these ideas unnecessarily complicated. "This feels more possible, more natural, because it's not proposing anything very extreme," he reiterated.
The implications for the search for extraterrestrial intelligence (SETI) are significant. For decades, SETI researchers have hunted for "technosignatures"—evidence of advanced civilizations, such as powerful laser beacons, robotic probes, or massive structures built to harness the energy of entire stars. But if Corbet is right, such grand technological feats may simply not exist. Instead, any alien technology out there might be only marginally more advanced than our own, making it much harder to spot.
Still, Corbet holds out a "reasonable chance" that we could one day make contact with ETCs. However, he cautions that such a discovery might leave us "slightly disappointed." Rather than unlocking a treasure trove of alien knowledge or technology, the encounter could simply confirm that "life in general would be rather common," and that our cosmic companions are, in many ways, just as limited as we are.
Not everyone in the scientific community is entirely sold on Corbet's hypothesis. Prof Michael Garrett, director of the Jodrell Bank Centre for Astrophysics, described the theory as a "fresh perspective," but expressed doubts about its underlying assumptions. "It projects a very human-like apathy on to the rest of the cosmos. I find it hard to believe that all intelligent life would be so uniformly dull," Garrett said. He suggested that any technological plateau could be far above our current level. In his own forthcoming paper in Acta Astronautica, Garrett leans toward the idea that "other, post-biological civilisations advance so rapidly that they slip beyond our capacity to perceive them." He added, "I hope I'm right, but I could very well be wrong. Nature always has some kind of surprise for us around the corner."
Other experts, such as Prof Michael Bohlander at the University of Durham, point to the possibility that evidence of extraterrestrial life may already have reached us in the form of unexplained aerial phenomena (UAPs). "If only a small percentage of those objects were found not to be man-made – and the capabilities displayed by them in numerous sightings at the very least suggest a state of advance far beyond current publicly known human technology – then the question posed by Fermi, 'Where is everyone?', could be answered empirically," Bohlander said.
It is worth noting that Dr Corbet's paper, while stirring up considerable discussion, has not yet been peer reviewed and is awaiting publication in Acta Astronautica. As the scientific community continues to debate the merits of radical mundanity—and as SETI researchers keep their ears to the sky—one thing remains certain: the universe still holds many secrets, and our search for cosmic company is far from over.
If the radical mundanity theory is correct, the answer to the Fermi paradox might be less about terrifying possibilities and more about the simple, relatable limits of technology and motivation. It’s a humbling thought, but perhaps a comforting one, too: maybe, out there among the stars, the neighbors are just as ordinary as we are.
