An Odd Reason Aliens Aren’t Calling: NASA Thinks ET is Simply Bored

A NASA scientist suggests that extraterrestrial civilizations might be just advanced enough to have already tried finding us and given up.

Some questions refuse to let go of humanity’s imagination, and none grips tighter than the possibility that we’re not alone in the universe. The question isn’t just whether others exist out there among the stars. The real puzzle, the one that keeps astronomers awake at night, is far more unsettling: if they’re out there, why haven’t they found us yet?

A Universe That Doesn’t Shout Back

The problem has a name now, borrowed from the physicist who first voiced it during a casual lunch conversation in 1950. Enrico Fermi asked what seemed like a simple question: “Where is everyone?” The logic behind his question was straightforward enough to be maddening. The galaxy sprawls across space with hundreds of billions of planets scattered throughout its spiral arms. The universe itself has existed for an almost incomprehensible span of time. Given these vast numbers and vast ages, if intelligent life is anything more than a cosmic fluke, then at least some of those civilizations should have advanced far enough to colonize the entire galaxy by now. We should see their fingerprints everywhere we look. Instead, we see nothing. Just silence echoing back from the void.

The question haunted scientists enough that it eventually became the centerpiece of an entire field of study. In 1961, a conference on the search for extraterrestrial intelligence convened at the National Radio Astronomy Observatory in Green Bank, West Virginia, bringing together some of the brightest minds wrestling with this cosmic puzzle. At that meeting, astronomer Frank Drake presented what would become his famous equation, a mathematical framework attempting to estimate the number of transmitting civilizations in the Milky Way Galaxy by multiplying together a series of factors: the rate at which stars form, the fraction of those stars with planets orbiting them, the fraction of those planets where the conditions are right for life, and on through several more variables until reaching the final question of how long such civilizations survive and continue broadcasting their presence.

When Drake and his colleagues plugged in their best guesses for each variable, the results were staggering. Their calculations suggested the galaxy probably harbored somewhere between 1,000 and 100 million planets with civilizations capable of communication. The sheer mathematical probability painted a picture of a universe that should be crowded with voices calling out to one another across the darkness. Instead, every time humanity aimed its radio telescopes at the stars, the silence became all the more disturbing.

Scientists began proposing explanations, each one stranger and more unsettling than the last. Perhaps aliens have become so advanced that their technology is indistinguishable from natural phenomena, rendering them invisible to our crude instruments. Perhaps Earth occupies a special place in some cosmic preserve, deliberately isolated from the rest of the galactic community like animals in a zoo. Perhaps, most disturbing of all, we really are alone, the only spark of consciousness in a dead universe.

That zoo idea gained formal structure in 1973 when John Ball, a radio astronomer working at MIT, proposed what he called the zoo hypothesis, suggesting that advanced civilizations might be deliberately avoiding contact to allow humanity’s natural development without interference. The concept has an eerie logic to it, uncomfortably similar to how humans study primitive tribes by observing them from a distance, careful not to contaminate their natural evolution with outside influence.

Under this framework, extraterrestrial life intentionally avoids communication with Earth to allow for natural evolution and sociocultural development, maintaining their distance much like zookeepers observing animals through one-way glass. The hypothesis even offers a glimmer of hope, suggesting that these watchers might choose to make contact once the human species has passed certain milestones, certain technological, political, or ethical standards that prove we’re ready for the revelation that we’re not alone, or perhaps they’ll wait until we force the issue ourselves by sending a spacecraft to one of their worlds.

The Mundane Alternative

Then, in the autumn of 2025, a different kind of answer emerged. Dr. Robin Corbet, an astrophysicist splitting his time between NASA’s Goddard Space Flight Center and the University of Maryland, Baltimore County, released a paper that took the scientific community by surprise with its title alone: “A Less Terrifying Universe? Mundanity as an Explanation for the Fermi Paradox.” His hypothesis cut through decades of increasingly exotic theories with an idea that was almost disappointingly simple.

Corbet’s proposal rests on what he calls the principle of “radical mundanity,” a term that deliberately pushes back against the grand visions of science fiction. He’s not interested in extraterrestrials who have cracked the secrets of faster-than-light travel or learned to manipulate the fabric of space-time itself. Instead, he envisions a Milky Way that houses a modest number of civilizations whose technology, while more advanced than humanity’s, isn’t dramatically so. They’re ahead of us, certainly, but not incomprehensibly so.

When Corbet sat down to explain his thinking to journalists, he reached for an analogy that made the idea immediately graspable. His theory suggests alien civilizations are more advanced than humans, he said, but not in ways that would seem like magic to us. Think of it as the difference between having an iPhone 42 rather than an iPhone 17. Better, yes. More refined, absolutely. But built on the same fundamental principles, operating within the same basic constraints. This feels more possible, more natural, he argued, precisely because it doesn’t propose anything very extreme.

The implications of this framework settle over you slowly, like cold water seeping through fabric. Under Corbet’s view, alien civilizations don’t possess faster-than-light travel that would let them hop between star systems as easily as we drive between cities. They haven’t figured out how to harness dark energy or dark matter, those mysterious components that make up most of the universe but remain stubbornly beyond our grasp. They’re not exploiting unknown laws of physics that would seem like sorcery to human scientists. They’ve simply hit a technological ceiling, a fundamental limit to what can be achieved with the physics we all share. And that ceiling, according to Corbet, sits just slightly above where humanity stands right now.

The Energy Hierarchy

To understand what Corbet means by a technological ceiling, you need to understand how scientists think about measuring the advancement of hypothetical civilizations in the first place. The standard framework comes from Soviet astronomer Nikolai Kardashev, who developed it back in 1964. Kardashev’s scale classifies civilizations based on something concrete and measurable: how much energy they can harness and use. It’s a remarkably elegant approach because energy consumption is something that can be observed from a distance, something that leaves detectable traces in the cosmos.

The scale starts with what Kardashev designated as Type I. A Type I civilization can harness all the energy available on its home planet, capturing and utilizing every bit of solar radiation that strikes its surface, every geothermal vent, every flowing river, every gust of wind. It sounds impressive until you realize that humanity hasn’t even reached this level yet. On the refined version of the scale that allows for decimal places, modern Earth rates at approximately 0.72. We’re not quite there yet, still struggling to fully master even planetary-scale energy use. When Kardashev first described a Type I civilization in 1963, he characterized it as having a technological level close to what Earth had achieved at that time, with energy consumption hovering around 4 times 10 to the 12th watts.

The next step up is where things get ambitious. A Type II civilization can control and utilize all the energy emitted by its parent star, an achievement that would likely require massive astro-engineering projects such as something called a Dyson sphere, a theoretical megastructure that completely encompasses a star to capture its entire power output. Picture it: a shell or swarm of collectors completely surrounding a sun, drinking in all of its light and heat, leaving nothing to radiate uselessly into space. According to Kardashev’s calculations, a Type II civilization would be dealing with energy consumption on the order of 4 times 10 to the 33rd ergs per second. The numbers become almost meaningless at that scale, but the implications are clear: a civilization at this level would possess capabilities far beyond current human comprehension.

Then there’s Type III, the apex of Kardashev’s original scale. A Type III civilization can command the energy of an entire galaxy, possibly by constructing Dyson spheres around most of the stars in that galaxy and linking them into a single vast network. The energy consumption would hit approximately 4 times 10 to the 44th ergs per second. At this level, a civilization wouldn’t just be manipulating individual star systems. It would be orchestrating the energy output of hundreds of billions of suns simultaneously.

The Kardashev scale does more than just provide a way to rank hypothetical aliens by their power consumption. It gives us a framework for thinking about what advanced civilizations might be capable of achieving and, crucially, what kinds of detectable signatures they might leave scattered across the cosmos. Kardashev himself calculated that detecting a Type I civilization would be extremely unlikely, although they would still be capable of receiving communications from others, while a Type II or Type III civilization would be able to transmit considerable amounts of information over vast distances, their signals strong enough to cross interstellar and even intergalactic space.

This is where the absence of signals becomes so puzzling. If even a handful of Type II or Type III civilizations exist in our galaxy, we should be able to see them. Their energy signatures should blaze across the sky. But we see nothing.

The Search for Dyson Spheres

Scientists haven’t given up looking. The search for Dyson spheres has become something of a holy grail in the hunt for advanced alien technology. The concept traces back to Freeman Dyson’s 1960 paper, where he deliberately chose the title “Search for Artificial Stellar Sources of Infrared Radiation,” recognizing that a Dyson sphere constructed by life forms dwelling near a Sun-like star would betray its presence through an unmistakable increase in the amount of infrared radiation pouring from that star system.

The physics is straightforward: if you wrap a star in collectors that absorb all of its visible light, all of that energy has to go somewhere. The civilization would use some of it, but the rest would be radiated away as waste heat, glowing in the infrared portion of the spectrum. A Dyson sphere would look like a star that’s somehow invisible in visible light but blazes when viewed through infrared-sensitive instruments. It should be impossible to miss.

The hunt intensified with modern technology. In 2024, two teams of astronomers, one in Sweden and one in Italy, launched systematic searches for possible evidence of Dyson spheres, combing through data from millions of stars looking for those telltale signs of excess infrared radiation. The Swedish team, working out of Uppsala University, thought they’d found something promising. Led by researcher Matías Suazo, they identified seven candidates around red dwarf stars, all of them relatively close by cosmic standards, within 900 light-years of Earth, and all of them exhibiting a peculiar characteristic: they appeared up to 60 times brighter in infrared wavelengths than expectations would suggest.

Sixty times brighter. That’s not a subtle anomaly. That’s the kind of excess that makes astronomers sit up and take notice, the kind that whispers “something strange is happening here.”

But finding candidates is only the first step. The research team had developed a specialized pipeline to process the combined data from three different astronomical surveys, specifically designed to search for partially completed spheres that would emit excess infrared radiation in the mid-infrared range, with the exact characteristics depending on the structure’s effective temperature. The challenge they faced was formidable. Nature produces plenty of objects that can mimic the signature of a Dyson sphere: circumstellar dust rings around young stars, glowing nebulae, background galaxies whose light gets warped and amplified by intervening matter, all of them capable of producing excess infrared radiation and creating false positives that look tantalizingly like alien megastructures until you examine them more closely.

The team applied filter after filter, eliminating candidates one by one. Starting with about 5 million initial objects, they applied multiple filtering steps designed to weed out anything that could be explained by natural astrophysical processes, and in the end, only seven potential Dyson spheres survived the scrutiny, objects for which the researchers felt confident they’d eliminated all the obvious natural explanations, candidates that showed no clear contaminators or signatures indicating an obvious mid-infrared origin.

Seven candidates out of five million stars. If even one of them proved to be real, it would be the most significant discovery in human history.

Then came the follow-up observations. When researchers conducted high-resolution imaging of the candidates using more powerful instruments, they found something deflating: three of the seven candidates had radio counterparts lurking in existing astronomy databases, and the most logical explanation for these radio signals was contamination from bright radio sources located far in the background behind the candidate stars, specifically active galactic nuclei, the intensely bright cores of distant galaxies powered by supermassive black holes.

The searches continue, each one more sophisticated than the last, and each one coming up empty. The lack of confirmed Dyson spheres aligns precisely with what Corbet’s mundanity principle predicts. If civilizations can’t or won’t build such megastructures, then we won’t find them.

The Plateau Problem

The idea that technology might have fundamental limits feels almost heretical in modern culture. We’ve spent more than a century riding a wave of exponential progress, watching each generation of technology outpace the last in ways that would have seemed impossible to our ancestors. The narrative of endless advancement became so ingrained in scientific thinking that when Kardashev and his contemporaries developed SETI theories in the mid-20th century, they naturally assumed that trend would continue indefinitely. Advanced aliens, they figured, would be as far beyond us as we are beyond medieval scholars. The idea that progress might simply stop didn’t fit the prevailing worldview.

But what if it does stop? What if there are hard limits to what can be achieved, limits imposed not by lack of imagination or effort but by the fundamental laws of physics themselves?

The universe still holds plenty of mysteries, certainly. Dark matter and dark energy together make up most of the cosmos, yet we can’t directly detect them or understand what they are. Solving these mysteries would undoubtedly expand our knowledge, possibly in profound ways. But knowing what dark matter is made of doesn’t automatically translate into useful technology. You can understand something completely and still not be able to harness it for practical purposes.

Recent evidence suggests that the age of exponential technological progress might already be ending, at least in some crucial areas. A major 2023 study published in the journal Nature looked at an enormous dataset spanning six decades: 45 million scientific papers and 3.9 million patents from six large-scale databases covering virtually every field of research and development. The researchers were looking for what they called “disruptive” innovations, the kind of breakthroughs that don’t just build on existing knowledge but fundamentally redirect entire fields of study in new directions. What they found was sobering: papers and patents are increasingly less likely to break with the past in ways that push science and technology in new directions, and this pattern held universally across all fields examined, remaining robust across multiple different citation-based and text-based metrics.

Think about what that means. It’s not that research has slowed down; if anything, more papers are being published now than ever before in human history. But those papers are becoming more incremental, more focused on refining existing ideas rather than proposing revolutionary new ones.

The study found that papers, patents, and even grant applications have become less novel and less likely to connect disparate areas of knowledge, and both of those trends are recognized as precursors of innovation. When researchers stop making unexpected connections between different fields, when they stop proposing ideas that seem to come out of nowhere, progress slows. The researchers even found evidence of this in an unexpected place: the gap between the year of discovery and the awarding of a Nobel Prize has been steadily increasing, suggesting that today’s contributions simply don’t measure up to the transformative breakthroughs of the past.

The language itself reveals the shift. The research showed that disruptive papers and patent titles tend to use words evocative of creation, discovery, and perception, words like “produce,” “determine,” or “measure,” language that suggests finding something genuinely new, while consolidating papers, the kind that build incrementally on existing work, tend to use more cautious language like “improve,” “enhance,” or “increase,” words that suggest refinement rather than revolution.

The pattern shows up in computing too, an area where exponential growth had been so reliable that it became known as a law. Moore’s Law, the observation that computing power roughly doubles every two years, held true for decades, but microprocessor architects have been reporting since around 2010 that semiconductor advancement has slowed industry-wide, falling behind the pace that Moore’s Law would predict. The problem is increasingly fundamental. As device dimensions shrink toward the atomic scale, controlling the current flow in those microscopically thin channels becomes more and more difficult, and modern nanoscale transistors have to take increasingly exotic forms just to function at all.

Horst Simon, who serves as deputy director of Lawrence Berkeley National Laboratory, put it bluntly when discussing the world’s most powerful supercomputers: they appear to be already feeling the effects of Moore’s Law hitting its limits, and for the last three years there’s been a kind of stagnation where the performance of the world’s top supercomputers isn’t improving the way it used to.

The numbers tell the story of a slowdown that’s impossible to ignore. More recent measurements show it now takes about 2.7 years for peak computing efficiency to double, a substantial slowdown from historical rates where a decade of doubling boosted efficiency by a factor of a hundred, compared to current rates that would require 18 years to see that same hundredfold gain.

Data from the United States shows that per capita energy usage has actually declined since 1979, not because Americans have become less technologically sophisticated, but because efficiency improvements mean we can do more with less. A civilization with a stable population and mature technology might naturally reach a point of energy equilibrium, where they’ve optimized everything they can optimize and have no compelling reason to keep pushing toward ever-higher levels of consumption. Why build a Dyson sphere if you don’t need that much energy?

This technological plateau carries implications that ripple outward in every direction. First, large-scale astro-engineering projects like Dyson spheres might not just be difficult to build; they might be either physically impossible given the constraints of real-world engineering or simply pointless if civilizations can’t use that much energy effectively and have no particular reason to generate it in the first place. Second, there would be no long-duration, high-power beacons broadcasting into space for millions of years. The cost of maintaining such a beacon, one powerful enough to be detected across the galaxy and robust enough to keep transmitting for geological timescales, would be immense. It would make far more sense to send probes out to gather information directly rather than hoping someone out there is listening and decides to respond.

Fear and Boredom: The Limits of Exploration

The mundanity principle has something to say about galactic colonization too, addressing one of the most puzzling aspects of the Fermi paradox. Calculations have shown repeatedly that even with technology not far beyond what humanity currently possesses, a civilization could theoretically spread across the entire galaxy in a relatively short time by astronomical standards. Self-replicating robotic probes could do the job: send them to nearby star systems, have them build copies of themselves from local materials, then send those copies to even more distant systems in an exponentially expanding wave. Given enough time, such a civilization could visit every star system in the galaxy.

So why don’t we see evidence of this? Why hasn’t anyone done it?

The mundanity principle suggests the answer comes down to a simple cost-benefit analysis, weighing means against motive. While interstellar travel to nearby stars might be technically feasible, even if extraordinarily difficult and expensive, launching a full-scale colonization program to reach billions of star systems scattered across the galactic disk requires that the benefits clearly outweigh both the costs and the risks involved. And the risks aren’t trivial.

The primary risk has acquired a memorable name borrowed from science fiction. The “Berserker hypothesis” comes from Fred Saberhagen’s novels featuring deadly self-replicating probes that spread across the galaxy destroying all life they encounter. The fear is straightforward: creating and releasing vast numbers of intelligent, self-replicating machines into the galaxy creates a scenario where you’ve essentially lost control of something that can reproduce and evolve beyond your ability to predict or manage. The consequences of such machines malfunctioning, developing unexpected behaviors, or simply following their programming too literally into unforeseen situations could be catastrophic.

This isn’t some exotic worry dreamed up by paranoid science fiction authors. It mirrors exactly the anxieties that currently swirl around the development of advanced artificial intelligence here on Earth. We’re already grappling with questions about how to ensure that AI systems remain aligned with human values, how to prevent them from pursuing goals in ways that cause unintended harm, how to maintain meaningful control over systems that might eventually become smarter than their creators. From a mundane perspective, it’s entirely reasonable to assume that other civilizations would share these concerns, perhaps even more acutely if they’ve had longer to contemplate the potential consequences.

On the other side of the equation, the potential benefits face a problem of diminishing returns that becomes more pronounced the longer an exploration program runs. The main reward for galactic exploration would be scientific knowledge: learning what’s out there, cataloging the diversity of planetary systems, perhaps encountering other forms of life or other civilizations. That’s valuable, certainly. But after you’ve explored thousands or millions of M-dwarf star systems, those small cool red stars that make up the majority of stars in the galaxy, and found them to follow broadly similar patterns, the scientific gain from visiting the next one starts to look marginal at best.

M-dwarf stars, also known as red dwarfs, burn their hydrogen fuel at such a leisurely pace that they can exist for trillions of years, far longer than the current age of the universe. They’re everywhere, making up roughly three-quarters of all stars in the Milky Way. If an exploring civilization methodically surveyed thousands of these systems and found them to follow predictable patterns, with similar types of planets in similar configurations facing similar evolutionary pathways, the motivation to continue surveying millions more would fade rapidly. How many times do you need to see the same thing before you’ve learned everything useful there is to learn?

This leads inexorably toward a state of cosmic ennui. A civilization’s exploration program would likely grind to a halt when the perceived risks of unleashing yet more self-replicating probes finally outweigh the dwindling scientific rewards of encountering yet another unremarkable star system populated by yet another plateau-level civilization that turns out to be fundamentally similar to all the others.

The calculation becomes simple when you strip away the romance: why risk creating potentially uncontrollable self-replicating machines that could run amok across the galaxy when the return on that investment is just more of the same data you’ve already collected a thousand times over? A civilization might enthusiastically explore its local neighborhood, those stars within a few hundred or even a few thousand light-years, carefully cataloging a representative sample of stellar systems and their planets, perhaps encountering a few other plateau-level civilizations along the way and exchanging information with them. But eventually, the pattern would become clear. The galaxy, for all its size, starts to look disappointingly similar wherever you go. At that point, the civilization turns its attention inward, focusing on problems closer to home, on maintaining and optimizing what it has rather than continuing to reach outward into the void.

What We’ve Found (And Haven’t)

When you put all the pieces together, the framework of radical mundanity paints a specific picture of our cosmic neighborhood. The galaxy contains a modest number of technological civilizations, perhaps on the order of 100,000 scattered across the hundreds of billions of stars in the Milky Way. That might sound like a lot, but spread across that vast volume of space, it means civilizations would be separated by thousands of light-years on average. All of them have reached a similar technological plateau somewhere below Type II status on the Kardashev scale. They’re not building Dyson spheres because they can’t or don’t need to. They’re not broadcasting powerful beacons into space because the cost doesn’t justify the uncertain benefits. They’re not launching fleets of self-replicating probes to every corner of the galaxy because the risks outweigh the rewards and the scientific returns have diminished to near zero.

When you examine the candidate technosignatures that researchers have found so far, each one tells a story that aligns with what the mundanity principle predicts. Consider the famous “Wow! signal,” that tantalizing burst of radio waves detected in 1977 that seemed to match exactly what SETI researchers expected an alien transmission to look like. It was a one-time event, never repeated, never confirmed despite decades of repeated searches turning telescopes back toward the same patch of sky. A mundane galaxy would produce persistent leakage radiation, the constant buzz of a civilization’s communications and radar systems, not a single powerful flash that appears once and then vanishes forever.

Or look at the candidate Dyson spheres that keep turning up in surveys, those stars that show peculiar infrared excess that could theoretically indicate a megastructure. In every case examined so far, astronomers have been able to propose plausible astrophysical explanations: young stars surrounded by dusty disks where planets are forming, older stars with debris disks from asteroid collisions, unusual stellar properties that just happen to produce excess infrared. The mundanity hypothesis actively prefers these natural explanations over claims of astro-engineering, not because of any bias against finding aliens but because the framework predicts that such structures simply wouldn’t exist.

Then there’s “Tabby’s Star,” that baffling object that showed irregular dimming patterns that briefly sparked wild speculation about alien megastructures under construction. Subsequent observations suggested more mundane explanations involving dust clouds, though the star remains genuinely strange and not fully explained. The mundanity view doesn’t require that we immediately understand every astronomical anomaly, only that we recognize natural phenomena will almost always turn out to be more likely than artificial ones.

The interstellar object ‘Oumuamua, that cigar-shaped visitor from another star system that tumbled through our solar system in 2017, generated intense speculation when some researchers suggested its trajectory and shape could indicate an alien artifact, perhaps a light sail from a defunct probe. The mundanity view treats such claims with deep skepticism. As Corbet himself pointed out, Earth is unlikely to be a particularly interesting place to visit for any extraterrestrial civilizations that might exist in the galaxy. What would motivate a civilization to send a probe on a trajectory that would take it through our solar system? We’re not particularly special, just one more G-type star among billions, orbited by one more rocky planet among countless others. A flyby mission to our system wouldn’t teach an advanced civilization anything they hadn’t already learned from exploring thousands of similar systems closer to home.

The same reasoning applies to reports of UFOs and unexplained aerial phenomena here on Earth. If our civilization hasn’t even achieved Type I status yet, if we’re still struggling to fully harness the energy resources of our own planet, then we represent nothing particularly novel or interesting to a modestly advanced extraterrestrial civilization that’s already explored extensively and reached its own technological plateau. They would have encountered countless pre-plateau civilizations before, each one at a similar developmental stage, each one still figuring out the basics. There would be nothing special about us, nothing worth the enormous cost and risk of sending vessels into our atmosphere for a closer look.

The Mathematics of Loneliness

Understanding the mundanity principle means grappling with the Drake equation, that famous formula that has both inspired and frustrated SETI researchers for more than six decades. The equation, formulated by Frank Drake in 1961, attempts to calculate the number of technically advanced civilizations in the Milky Way by multiplying together a series of factors: the mean rate at which stars form in the galaxy, the fraction of those stars that have planetary systems, the number of planets in such systems that are ecologically suitable for life to arise, the fraction of those suitable planets where life actually develops, the fraction where that life evolves to an intelligent form, the fraction where that intelligence develops technology capable of interstellar communication, and finally, critically, the average lifetime of such advanced civilizations.

Each factor represents a filter, a hurdle that has to be cleared for a civilization to exist and be detectable. When you multiply them all together, you get an estimate for N, the number of civilizations we might be able to communicate with right now.

When Drake and his colleagues sat down to work through the equation in 1961, they used what they considered educated guesses: they assumed roughly one star formed per year on average over the life of the galaxy, that somewhere between one fifth and one half of all stars would have planets orbiting them, that stars with planets would typically have between one and five worlds capable of supporting life, and they made their best guesses for the other factors based on the limited data available to them in the early space age. Their calculations led them to conclude that the galaxy probably harbored somewhere between 1,000 and 100 million planets with civilizations capable of communication, a range so wide it’s almost meaningless but still powerfully suggestive that we’re not alone.

The problem is that nobody really knows what numbers to plug into the equation. There’s considerable disagreement on the values of these parameters, so much so that depending on which assumptions you make and which values you choose, the Drake equation can give you results ranging from N being much less than 1, meaning we’re likely alone in the entire galaxy, all the way up to N being much greater than 1, implying there could be many thousands or even millions of civilizations we might potentially contact.

If you want to be pessimistic about it, you can combine NASA’s best estimates for star formation rates with the rare Earth hypothesis that suggests life-bearing planets are extraordinarily uncommon, add in conservative assumptions about intelligence and communication, and end up with results suggesting that we’re probably alone in this galaxy and quite possibly in the entire observable universe.

The last variable in the equation, that final L representing the length of time civilizations release detectable signals into space, remains the most uncertain of all and arguably the most important. It’s the one factor that depends entirely on behavior rather than astrophysics or biology, making it fundamentally unpredictable. If civilizations characteristically destroy themselves within just a few decades or centuries of developing radio technology, whether through nuclear war, ecological collapse, engineered pandemics, or some other catastrophe that we haven’t even imagined yet, then the galaxy would be essentially empty of detectable life at any given moment. Civilizations would constantly be flickering into existence and then winking out, never overlapping, never able to find each other across the vast distances and vast timescales involved.

On the other hand, if civilizations typically survive for millions or even billions of years once they make it past whatever early dangers threaten them, then the galaxy could be absolutely crowded with long-lived civilizations, enough of them that several should be within detection range of our radio telescopes right now.

The mundanity principle offers a third possibility, a middle ground between extinction and immortality. Civilizations survive, at least many of them do. They don’t self-destruct in nuclear fire. They don’t transcend to higher dimensions or upload themselves into virtual realities where they have no need or desire to communicate with the physical universe. They simply reach a technological plateau, realize that the galaxy is much more uniform and much less interesting than they’d hoped, and eventually stop broadcasting or exploring because the effort outweighs the rewards. They’re still there, still maintaining their civilizations, still going about their daily lives. They’ve just stopped shouting into the void because they’ve realized no one interesting is going to shout back, and they’ve found better uses for their time and energy than broadcasting messages that probably won’t answer back with anything they haven’t already figured out for themselves.

Not Everyone Agrees

Corbet’s radical mundanity principle hasn’t been universally embraced by the scientific community, which is exactly what you’d expect for a hypothesis that challenges decades of assumptions about how to think about extraterrestrial intelligence. Professor Michael Garrett, who directs the Jodrell Bank Centre for Astrophysics, one of the world’s premier radio astronomy facilities, appreciated what he called the “fresh perspective” that Corbet brought to the problem but didn’t hold back in voicing his reservations.

Garrett’s main criticism cuts right to the heart of the mundanity principle: he argues that the theory projects very human-like apathy onto the rest of the cosmos, saying he finds it hard to believe that all intelligent life would be so uniformly dull that they’d all reach the same conclusions about exploration being not worth the effort. It’s a fair point. The theory assumes that all civilizations, regardless of their evolutionary history, their biology, their culture, their psychology, would all eventually decide that galactic exploration just isn’t worth continuing. That seems like a huge assumption about convergent behavior.

Garrett also points out that any technological plateau could exist at levels far above humanity’s current capabilities. Just because we haven’t figured out how to harness exotic physics doesn’t mean it’s impossible; it might just mean we haven’t been smart enough yet or haven’t accumulated enough understanding. An alien civilization might be stuck at a technological plateau, sure, but that plateau might still involve capabilities that would seem incomprehensible to us.

In his own paper, scheduled for publication in the journal Acta Astronautica, Garrett lays out his preferred alternative theory, one that goes in exactly the opposite direction from Corbet’s mundanity principle. He suggests that other, post-biological civilizations, societies that have transcended their biological origins and transformed into something radically different, might advance so rapidly that they slip beyond human capacity to perceive them altogether. They’re not stuck at a mundane technological level; they’ve rocketed past us so completely that we can’t even recognize their activities as technological. It’s an intriguing idea, though Garrett readily acknowledges he might be completely wrong. Nature, he notes with the humility of a veteran scientist, always has some kind of surprise waiting around the corner.

Professor Michael Bohlander, an expert on SETI policy and law working at the University of Durham, throws another possibility into the mix, one that Corbet’s framework would dismiss. Bohlander suggests that evidence of extraterrestrial visitation may have already reached Earth in the form of those unexplained aerial phenomena that military pilots and radar operators keep reporting. He makes the point that if even a small percentage of those objects turn out not to be human-made, and if the capabilities displayed by them in numerous documented sightings, capabilities that include apparent velocities and accelerations far beyond current publicly known human technology, represent genuine alien craft rather than misidentifications or sensor errors, then Fermi’s question of “Where is everyone?” would have a simple empirical answer: they’re already here, and they have been for a while.

The criticism of radical mundanity often focuses on its assumptions about motivation and behavior. Critics of similar explanations like the zoo hypothesis emphasize how these frameworks assume a great deal about the mentality and sociology of alien civilizations, projecting human-like thought patterns and decision-making processes onto entities that might be profoundly different from us in ways we can’t even imagine. The mundanity hypothesis faces parallel challenges: why would all civilizations follow similar paths? Why would they all lose interest in exploration at roughly the same technological level? What about civilizations that are genuinely alien in their thinking, that might have motivations and drives completely foreign to human psychology?

Corbet has a response to these objections, and it’s rooted in physics rather than psychology. His answer is that the laws of physics are universal. They apply everywhere, to everyone, regardless of what you look like or how you think or what evolutionary path brought you to sentience. If there are fundamental limits to what can be achieved with the known laws of physics, limits imposed by thermodynamics and relativity and quantum mechanics and all the other deep principles that govern how the universe works, then all civilizations would eventually bump up against similar walls. It’s not about motivation at that point; it’s about possibility. A civilization can’t build what physics won’t allow, no matter how motivated they might be to try. The ceiling exists independent of anyone’s desires.

A Quiet Hope

The mundanity hypothesis resolves the Fermi Paradox in a way that manages to be neither lonely nor terrifying, threading a careful path between the two extremes that have dominated thinking about extraterrestrial life. It suggests a universe that’s quietly populated by civilizations that aren’t incomprehensibly different from what humanity might one day become if we manage to survive our current challenges and continue advancing.

The implications for detection are actually somewhat encouraging in this framework. In his paper, Corbet explains that even a technologically mundane world should still be detectable via leakage radiation, the unintentional radio signals that leak out from a civilization’s communications and radar systems, and such a discovery may not be too far off in the future if radio telescopes continue to advance in sensitivity and capability. As our instruments become more sophisticated, as projects like the Square Kilometre Array come online with unprecedented ability to detect faint radio signals from enormous distances, we may finally be able to pick up the faint, unintentional electromagnetic buzz from a nearby civilization, their equivalent of our television broadcasts and planetary radar and satellite communications, all of it leaking out into space whether they intend it to or not.

Jason Wright, an astronomy and astrophysics professor at Penn State who specializes in technosignature research, explained the logic behind infrared searches: if any technology is using lots of solar energy, even something as simple as giant solar panels in space that block just one percent of the star’s light, there would be a huge, unmistakable infrared signature radiating from that system. The search continues with increasingly sophisticated instruments scanning the sky, looking for any deviation from what nature should produce on its own.

If we do finally make that detection, if we pick up that first confirmed signal from another civilization, it would undoubtedly be one of the most momentous events in human history, proof that we’re not alone, that intelligence has arisen elsewhere, that the universe is populated by minds other than our own. But the mundanity principle suggests it might also be slightly disappointing in some ways. We wouldn’t be receiving the secrets to faster-than-light travel, no revolutionary physics that would let us hop between stars as easily as we drive to the grocery store. We wouldn’t get blueprints for unlimited energy sources or instructions for building matter compilers that could manufacture anything we need from raw atoms. We’d simply get the quiet confirmation that we’re not alone, followed by the gradual realization that our cosmic neighbors are dealing with the same fundamental constraints and limitations that we face.

There’s another implication hiding in the mundanity framework, one that offers genuine hope. If technological civilizations arise in only modest numbers, scattered sparsely across the galaxy, that strongly suggests that simple life itself is not rare at all. Think about it: if the filter that keeps civilizations scarce operates at the level of technology rather than at the level of basic biology, then the galaxy may be absolutely teeming with planets that harbor some form of life, even if very few of those planets go on to develop beings capable of building radio telescopes and wondering if anyone else is out there. This gives concrete reason for optimism that future missions designed to search for biosignatures in the atmospheres of nearby exoplanets, looking for chemical combinations that can only be produced by living organisms, may actually succeed in finding them.

NASA scientists have already begun expanding their thinking about what technosignatures to look for beyond just radio signals, considering possibilities like laser pulses deliberately aimed at other star systems, signs of artificial chemicals in the atmospheres of distant planets such as chlorofluorocarbons, those same CFCs that were once widely used as refrigerants here on Earth before we realized they were destroying our ozone layer, or even the detection of artificial light, the glow of city lights visible on the night side of a rocky, Earth-sized planet orbiting a nearby star.

The radical mundanity principle offers an answer to one of science’s most significant questions by proposing a universe that is fundamentally less extreme, less dramatic, and less terrifying than the scenarios envisioned by either the optimists who imagine Type III civilizations reshaping galaxies or the pessimists who fear we’re utterly alone in a dead cosmos. It’s a universe where humanity occupies neither a uniquely isolated position as the only conscious beings in existence, nor finds itself in the presence of incomprehensible alien beings whose technology might as well be magic. Instead, we’re simply one civilization among a modest number of others, all of us making our way through the cosmos, all of us facing similar challenges, all of us constrained by the same fundamental laws of physics.

The Weight of Evidence

Corbet’s paper has not yet undergone peer review, that crucial process where other scientists examine the methodology and reasoning to look for flaws or oversights, but it has already begun circulating through the community and presenting a framework that other scientists have called sobering in its implications. The silence emanating from the stars, that Great Silence that has puzzled and disturbed scientists since the dawn of radio astronomy, might not be a mystery requiring exotic solutions involving zoo hypotheses or Prime Directives or civilizations that have transcended physical reality. It might simply be the sound of civilizations that explored enthusiastically for a while, discovered that there wasn’t much genuinely new to find out there in the vast darkness, and eventually turned their attention back to matters closer to home.

The evidence supporting this view doesn’t come from any single dramatic discovery but rather from an accumulation of trends, each one pointing in the same direction. Computing power isn’t growing exponentially anymore; the reliable doubling predicted by Moore’s Law has slowed to a crawl as we approach fundamental physical limits on how small we can make transistors. Scientific papers are becoming less disruptive, less likely to overturn existing paradigms or send fields of research spinning off in entirely new directions. Energy consumption in developed nations has plateaued despite continued economic growth, suggesting we’re learning to do more with less rather than constantly demanding more power. Searches for megastructures around distant stars keep finding natural explanations for every anomaly rather than evidence of astro-engineering.

None of this proves the mundanity hypothesis correct. Science doesn’t work through proof; it works through accumulating evidence and building frameworks that explain that evidence better than competing theories. The universe could still harbor Type III civilizations somewhere out there, societies so advanced that they’ve learned to hide themselves perfectly from our instruments, rendering themselves completely invisible to our searches. Or perhaps aliens do exist but operate on principles so profoundly foreign to human experience that we wouldn’t recognize them as intelligent even if we encountered them directly. The answer to the Fermi paradox might still turn out to be something stranger than anyone has yet imagined, some explanation that future generations will look back on and wonder how we could have missed something so obvious.

But Corbet’s framework offers something valuable beyond its specific predictions: it’s testable. It makes clear statements about what we should and shouldn’t find as our instruments continue to improve and our searches become more comprehensive. If the mundanity principle is correct, we should eventually detect faint radio leakage from nearby civilizations as our radio telescopes become sensitive enough to pick up unintentional transmissions from nearby star systems. We shouldn’t find Dyson spheres, not real ones, just natural phenomena that superficially resemble them. We shouldn’t find galaxy-spanning networks of communication linking billions of worlds. We should find civilizations that look, technologically speaking, something like ourselves: more advanced, certainly, but recognizably working with the same basic toolkit, the same fundamental physical principles, the same constraints.

The galaxy under this view isn’t empty, that most depressing possibility where we’re genuinely alone, the only conscious beings in a vast unconscious cosmos. But it’s also not particularly interested in us, and for understandable reasons. We’re not special. We’re just one more civilization among many, all of us at roughly similar technological levels, all of us having explored enough to realize that the galaxy is far more uniform than we’d hoped, all of us having turned our focus inward to the problems and opportunities that exist closer to home.

That outcome might seem anticlimactic when measured against the transcendent visions of science fiction, those grand narratives where humanity joins a galactic community of ancient wise civilizations or discovers technologies that render our current limitations obsolete. But there’s something oddly comforting about the mundane scenario once you sit with it for a while. We’re not alone in struggling with hard problems, with questions that don’t have easy answers, with technologies that prove more difficult to develop than we’d hoped. We’re not alone in hitting limits that seem insurmountable. We’re not the only ones who explored outward with great enthusiasm and optimism, only to discover that the cosmos, while certainly vast, is also rather repetitive once you’ve seen enough of it.

If Corbet turns out to be right, the universe is full of civilizations very much like ours, each one muddling through as best they can, each one making incremental progress on difficult problems, each one trying to build a decent life for themselves within the constraints that physics imposes on all of us. Each one looking up at the stars occasionally on clear nights and wondering if anyone else is out there doing the same thing, experiencing that same mixture of curiosity and loneliness that comes from contemplating our place in the cosmos.

The answer, according to radical mundanity, is yes. They’re out there. They’re wondering too. They’re just not shouting about it anymore because they learned long ago that the galaxy doesn’t have much new to tell them, and they’ve found better uses for their time and energy than broadcasting messages into a void that probably won’t answer back with anything they haven’t already figured out for themselves.

References

NOTE: Some of this content may have been created with assistance from AI tools, but it has been reviewed, edited, narrated, produced, and approved by Darren Marlar, creator and host of Weird Darkness — who, despite popular conspiracy theories, is NOT an AI voice.