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What if the truth isn’t out there?

The wishful thinking behind the search for alien life.

It’s possible humans are the only industrial civilization in the entire galaxy.
ESO/P. Horálek

The US military’s official report on UFOs is here, and its conclusion is scintillating: There’s some stuff in the sky, the government isn’t sure what it is, there’s no evidence that it’s aliens, but also no one’s ruling out aliens. So in conclusion, the UFOs are part of life’s rich pageant and anything is possible.

The nine-page report released by the Director of National Intelligence’s (DNI) office last week, formally titled “Preliminary Assessment: Unidentified Aerial Phenomena,” says a little bit more than “we know nothing.” But that is the main takeaway. “Limited Data Leaves Most UAP Unexplained” reads the report’s first subject heading.

That takeaway comes as something of an anticlimax capping off a period of frenzied speculation over UAPs (the new preferred term for “UFO”). The current mania was kicked off by a 2017 New York Times A1 article revealing the existence of a quiet Pentagon program analyzing strange aerial sightings by pilots. Since then, a steady stream of mainstream news coverage and Pentagon disclosures have kept UAPs in the public eye, complete with details about their allegedly fantastical, above-human capabilities.

In the immediate wake of the DNI report, no minds have been changed. The skeptics are still skeptical. Believers in the “extraterrestrial hypothesis” (ETH) still believe.

Which is about right. This report simply doesn’t contain enough new information to move anyone’s assessments much in one direction or another. It was mostly meant to summarize the UFO sightings the Pentagon has looked at, rather than explain those sightings. It was reportedly written in half a year by two people working part-time; it is not a large-scale evidence review like the 9/11 Report.

A still from the GOFAST UFO video.
Official UAP Footage from the USG

So the UFO-curious public is left more or less where it started before this latest round of UFO stories: not knowing what these objects in the sky are or where they’re from or what if anything they tell us about the universe.

Let me lay my cards on the table here: I’ve long been on the skeptics’ side. I don’t think we have any evidence that these UAPs are a sign of intelligent life on a different planet. But I also know that it’s a question we have to get to the bottom of, and to do that the government needs to allocate a bit more in the way of research funding.

We have to get to the bottom of this question because the truth about UFOs — particularly if the extraterrestrial hypothesis happens to be somehow true — could clarify humans’ role in the universe.

Physicists, astronomers, philosophers, and other smart people have been trying to suss out what the existence or nonexistence of intelligent life elsewhere in the universe could mean. It could be we’re all alone in the universe, which leads to certain mind-breaking implications — one of which is perhaps humanity has a moral duty to preserve civilization because it exists nowhere else in the vast expanse of space. Or it could be that we do have cosmic neighbors, but that those neighbors haven’t reached out because they face difficult challenges — challenges that could be waiting for us in our own future and that could inform how we act today.

In other words, the UFO question is a subquestion of a much broader, more profound inquiry into the future of humanity.

Fermi’s paradox and the puzzle of intelligent life elsewhere

A finding that UFOs represent an alien civilization visiting Earth would be crucially important, first and foremost because it would answer a question scientists have been asking for at least the last century: Where is everybody?

The universe is almost incomprehensibly vast: In the Milky Way galaxy alone, there are hundreds of billions of stars, and as many as 6 billion of them could be Sun-like stars with rocky Earth-like planets orbiting them. There are hundreds of billions if not trillions of galaxies alongside the Milky Way.

The summer Milky Way from the Howse Pass Viewpoint at Saskatchewan River Crossing in Banff National Park, Alberta.
Alan Dyer/VW PICS/Universal Images Group via Getty Images

It would be strange for humans to be the only intelligent life (or, at least, the only life of above-chimpanzee intelligence) in all that vastness. And, intuitively, it seems like some of our peers should have surpassed us and developed the ability to send probes thousands of light-years away to observe us.

This puzzle is commonly known as Fermi’s paradox, after its articulation by the 20th-century physicist Enrico Fermi, and it has fascinated astronomers, physicists, and science fiction fans for decades. As Liv Boeree explained for Vox, much of the literature on the Fermi paradox relies on a model known as the Drake equation, devised by physicist Frank Drake to estimate the number of “active, communicative, extra-terrestrial civilizations” in our galaxy.

The equation includes some variables astronomers are able to estimate (like the rate of star formation in the Milky Way and the fraction of stars with planets) and some inherently speculative ones, like the fraction of planets that develop intelligent life. The Drake equation is thus quite imprecise, and it requires plugging in numbers where researchers have tremendous uncertainty.

In 2017, Anders Sandberg, Eric Drexler, and Toby Ord of the Future of Humanity Institute attempted rough estimates of the odds that human civilization is alone in the galaxy and universe by giving uniform odds to a number of different parameters. For instance, they estimated that the share of planets with life that also have intelligent life could be anywhere from 0.1 percent to 100 percent, and gave equal odds to every number in that range.

They then incorporated the fact that we haven’t observed other intelligent civilizations, which should lower our estimated odds of their existence. The paper concluded that there’s a 53 percent to 99.6 percent chance of humans being the only intelligent civilization in the Milky Way, and a 39 percent to 85 percent chance of being alone in the observable universe.

The threat of the Great Filter

The optimistic read, as outlined by Sandberg elsewhere, is that this finding should reduce our fear that humans face a huge extinction event in our future.

How does that follow? Well, one common explanation for humans’ apparent loneliness in the universe is that intelligent life is actually incredibly common — but almost always destroys itself at some point. Either a civilization’s own technology grows so advanced and dangerous that it wipes itself out, or natural phenomena like meteors or supervolcanoes strike before the civilization has the chance to send probes to look at us.

This theory is known as the Great Filter, and it has a certain terrifying plausibility to it. Humanity has already developed tools capable of wiping itself out, or else shrinking itself to a size so small that it cannot endure and sustain itself: nuclear weapons, engineered pathogens, possibly greenhouse gas emissions.

Oxford’s Ord, in last year’s book The Precipice: Existential Risk and the Future of Humanity, roughly estimates the odds of a human-caused extinction or extinction-level event in the next century at about one in six.

There’s a lot of uncertainty around those estimates. But one in six is a very significant risk. Most election forecasters gave lower odds to a Donald Trump victory in 2016.

And if our loneliness in the universe is evidence that every other civilization has destroyed itself in a fashion like this, then one in six might be an overly optimistic estimate. If, on the other hand, the difficult-to-pass “filter” is in our past (say, at the stage in which lifeless molecules combined to create viruses and bacteria), as the Sandberg/Drexler/Ord research suggests, then our loneliness need not imply a grave threat in our future.

Researchers interested in the potential risk posed by the Great Filter tend to focus on searching for “biosignatures” or “technosignatures”: observable attributes of planets elsewhere in the galaxy that might give evidence of life or human-level technology.

Generally, the hope is to not find these signatures. If we see evidence that there are lots of planets with life up to or equal to human levels of sophistication, but not at levels of sophistication that exceed humans, that strengthens the argument that the filter is in the future, that humans will (like all technologically advanced civilizations) find a way to destroy ourselves.

“If the search for biosignatures reveals that life is everywhere while technology is not, then our challenge is even greater to secure a sustainable future,” researchers Jacob Haqq-Misra, Ravi Kumar Kopparapu, and Edward Schwieterman recently concluded in an article for the journal Astrobiology.

If (and I must stress that this is a quite unlikely “if”) UFO sightings on earth are actually evidence that an advanced alien civilization has developed a system of long-distance probes that it is using to monitor or contact humanity, then that would be an immensely hopeful sign in Great FIlter terms.

It would mean that at least one civilization has far surpassed humanity without encountering any insurmountable hurdles preventing its survival. It would also mean Earth need not be the universe’s sole protector of intelligent life and civilization, meaning that if we do destroy ourselves, all is not lost, cosmically speaking.

What if we’re all alone?

Getting to the bottom of the UAPs and investigating whether there’s intelligent life elsewhere is important, and it’s probably worth devoting government resources toward solving the mystery.

But I also worry that belief in the extraterrestrial hypothesis is a kind of wishful thinking. If it’s wrong, and a Great Filter is in our future, that suggests our species is in immense danger. It would mean there are many, perhaps millions or billions, of civilizations like ours around the universe, but that they without fail destroy themselves at some point after they reach a certain level of technological sophistication. If that happened to them, it’ll almost certainly happen to us too.

A person with two cameras on tripods stands on a hilltop at night with the starry sky behind them.
Cihan Onen of Bitlis Eren University takes photos of the Milky Way, in Turkey on September 22, 2020.
Ahmet Okur/Anadolu Agency via Getty Images

If the extraterrestrial hypothesis is wrong simply because we’re the only species that has even gotten this far, that’s alarming for a different reason. It implies that if we screw up, that’s it: The universe would be left as a desolate compilation of stars and planets without any thinking creatures on them. Nothing capable of empathizing or acting morally would exist anymore.

Skeptic though I am, there is a part of me that wants the objects in the sky to be aliens because the alternative is so dismal. I want to know what these objects really are because the stakes are high enough that we need to get this right. But in a way, our current state of relative ignorance can be a bit of a silver lining — there’s comfort in the thought that we don’t know the answer yet, and that we can’t quite close the door on the possibility of life beyond Earth.

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