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What If We Really Are Alone in the Universe?

The recent “cosmic realist” trend in hard sci-fi — expressed most severely in James Gray’s Ad Astra — comes at an existentially staggering moment for our relationship to both the planet and the cosmos.

Brad Pitt as Major Roy McBride in James Gray's Ad Astra. (Francois Duhamel / Twentieth Century Fox)

“Two possibilities exist: Either we are alone in the universe or we are not,” according to Arthur C. Clarke, the author of 2001: A Space Odyssey. “Both are equally terrifying.”

Much science fiction of the last century has assumed the first of Clarke’s terrifying possibilities, that we are not alone — that the cosmos is teeming not just with life, but with intelligent life. The primary questions this literature asked, in hundreds of different ways, were those such as: What would extraterrestrial intelligence be like? How would we recognize it? What would be its response to us? What would be our response to it?

Ostensibly about little green men, these were nevertheless profound questions answered in the pages of cheap paperbacks or by screen actors suited up in wobbly rubber masks. The questions were as serious as any asked by the authors of more respectable literary fiction. They reflected some of the deepest uncertainties that have troubled humanity since our first days on the African savannah, staring up at the great river of stars of the Milky Way: Why are we here? Where do we come from? And, above all: What is it to be a human? For us to ask what an alien soul would be like requires at least an assumption of what a human soul is like.

And yet for all our neuroscience, biochemistry, and philosophy, we still don’t have good answers: terms such as “intelligence,” “mind,” and “sentience” stubbornly resist rigorous definition; the hard problem of consciousness — how this state of self-awareness arises from (we assume) non-conscious chemicals — remains as much of a hard problem as ever.

But the second of Clarke’s two terrifying possibilities has, with a handful of exceptions, until recently remained unexplored within popular culture, particularly within cinema.

This is understandable. Writing in 1951 at the dawn of the Space Age in his book of popular astronautics, The Exploration of Space, Clarke said that we stood then at a pivot between two eras brought about by the advent of the rocket. This was the point at which “the childhood of our race was over and history as we know it began” — Earth’s solar system being relatively young compared to the age of the galaxy (and certainly the universe), and industrial modernity a mere three hundred or so years old.

If an alien civilization had its version of an industrial revolution just a million years before ours or even just a thousand years — and the universe appeared to have given billions of years’ worth of head starts to the presumed myriad of other planets with intelligent life — they would be unfathomably advanced in comparison to us. Per Clarke and so many others, our “childhood’s end” was the moment we would take our place among the adults of the cosmos.

It was an era of optimism, even presumption, about humanity’s place among the stars. Of course we would have lunar colonies by the end of the twentieth century and Martian outposts somewhere around now. What made this optimism nevertheless terrifying was the unknown of what the adults of the cosmos would be like. Would they be peaceful? Would they be so advanced that they would treat us as we treat a fruit fly or a rat, or a lab mouse, or even Laika the space dog? Would they treat us as food, the way we treat cows and pigs? Would they carry with them genocidal new diseases the way Europeans did to the Americas? Would they be the disease? Would they demolish the Earth to make way for a hyperspace bypass?

James Gray’s Ad Astra is one of the first films to explicitly consider the terror of Clarke’s second possibility. What if there are no aliens? What if, in the end, it’s just us?

Ad Astra and the Loneliness of Space-Capitalism

It is the near future, “a time of hope and conflict,” as the opening title card tells us. Major Roy McBride (Brad Pitt) is in his space suit at work atop the “International Space Antenna” in low-Earth orbit when a mysterious surge from deep space nearly destroys the structure and knocks Roy off. Roy’s Felix Baumgartner–style opening free fall sequence, beating all HALO jumps of recent cinema for its success in inflicting vertigo, seems to be the point: we start and end with sequences in which the ground has been knocked out from beneath characters.

Earth and its outposts on the moon and Mars have been badly hit by what is termed “the surge.” Roy, the son of hero-astronaut Clifford McBride — the first human to travel to Jupiter, the first to travel to Saturn — is told by US Space Command that the source of the surge is the Lima Project in orbit around Neptune.

The Lima Project had been established under the direction of Clifford to extend the up-till-then fruitless search for intelligent life to the farthest reaches of the solar system. Sixteen years earlier, all communication with the project had ceased, and Clifford and his crew were presumed dead. Long since having come to terms with the grief of losing his father, Roy is now informed by USSPACECOM that they believe Clifford is alive and possibly responsible for the surge. We then follow Roy through the solar system, visiting the moon, Mars, a ship in distress, and eventually Neptune, on his mission to reestablish contact with his father.

Roy is dispassionate, level-headed, almost emotionless. Regardless of what threat arises, his heart rate never moves beyond 80 BPM. He passes without incident all but one of the automated psychological evaluations he must regularly take. He has been picked precisely for this, well, inhuman reserve. Confronted with the claustrophobic agoraphobia of a tin can in an infinite vacuum and the thousand other extreme dangers of space travel, Roy’s heart is unmoved. A perfect astronaut.

The common reading of the film has been that all this is really about a son’s attempt to reach out to a distant father, of the inability of us all to understand the other. What greater distance can a son and an absent father travel than that between Earth and Neptune? “Only connect!” as E. M. Forster insisted.

It is not so much that this is wrong, but that it is too abstract.

It is true that when Roy finally reaches his father, Clifford blankly tells him that he was content to leave his son and wife because the search for intelligent life was so much more fulfilling, so much more important. But Clifford’s soliloquy also tells us why communication with Earth was disrupted, what happened to his crew, and why he has in effect gone mad.

We see flashes of Europa, Enceladus, Titan, Ganymede — all the sites that in the real world today we reckon are the best hope for discovery of life in the solar system — as Clifford recounts how no matter where they looked, they found no life. After years of searching, his crew wanted to concede that there was no life out there and to return home. Clifford insisted that absence of evidence is not evidence of absence and killed his crew when they mutinied, wanting the search to continue.

In a universe where we are the only intelligent life there is, that there has ever been, and the Earth the only place where any life has been, intelligent or otherwise, Forster’s command to “only connect” becomes ever more imperative. If it’s only us, it makes us even more important, so much more precious than we imagined. It casts us humans not merely as one sentient species among billions, but as the sole way in which the universe became aware of itself. It is the story of the universe becoming conscious through us.

Without such consciousness, there is no point, no purpose to the universe. Nothing matters. There is no “ought” in physics, only an “is.” There is no “ought” in biology either, no progressive direction to evolution (what is termed “orthogenesis”). Even if life on earth were to continue, but continue without us, still nothing would matter, as it is true that while individual organisms struggle to continue to be, life does not care whether it exists (life on Earth, at least twice before, came close to wiping itself out). An Earth without humans but still with other life would only matter insofar as there would at least remain a chance for intelligent life to reemerge. Only intelligent life can create purpose.

There is a sequence midway through Ad Astra where Roy comes across a ship in distress, the exploration of which reveals that its crew have all been killed by raging baboons, the escaped subjects of a scientific experiment. It is something of a horror-filled series of scenes, appearing at first to be from a different, less meditative film than Ad Astra, perhaps an Event Horizon or even Alien.

Though appearing out of place, the baboon sequence could be read as an allegory for how the inhospitable environment of space will inevitably make us crazy. But a still deeper reading asks, could it not instead be a rhyme for the sheer terror of realizing that we inhabit a lonely cosmos where humans are the only intelligent life? Is such a realization any less vertigo-inducing, any less deranging?

If the film is understood this way, then the sequence where Virgin Galactic takes our hero to the moon (charging $125 for a blanket and pillow) has a more expansive meaning than at first glance. As does the brief sequence on the moon in which we see a base not filled with the scientific equipment of a ’70s-era Doctor Who, Lost in Space, or Star Trek, but instead dominated by the likes of Applebee’s, Subway, DHL, and tourist-trap cringe. If the film were primarily a critique of the banality of a capitalism now spread throughout the solar system, much more time would have been spent by the filmmaker in this space. But these scenes are very brief.

Gray’s critique is indeed one that laments what capitalism is doing, as we know from his comments to the press. “If we were having this conversation in 1960, we could talk about the counterweight of the communist or socialist dictatorship bloc. But today there’s not really a counterweight to market capitalism,” he told CNET. “It’s an unstoppable force. In the developed nations, the gap between the richest and the poorest is growing ever larger. And why would we project that space would be any different?”

But the film’s concern with capitalism appears to plunge deeper. If capitalism, unconscious force that it is, would extinguish human existence so long as the commodities that threatened such extinction (such as, for example, fossil fuels) continued to be profitable in the absence of some non-market intervention, then it is not merely the human race that is threatened, but a conscious universe itself. Capitalism would turn a lonely cosmos into a soulless cosmos.

Hollywood’s Turn Toward Space-Pessimism

Ad Astra may be among the first films to explicitly place Clarke’s lonely cosmos possibility at its heart, but a raft of hard sci-fi films in the last few years, auteur-driven works set in space such as Duncan Jones’s Moon, Alfonso Cuarón’s Gravity, Christopher Nolan’s Interstellar, Ridley Scott’s The Martian, and Damien Chazelle’s First Man, have also begun to consider the same question but posed in a different way: If the rest of space is as incorrigibly inhospitable as it increasingly appears to be, does it make sense to even travel to other worlds? This is just another way of saying that there may as well be no other aliens.

Duncan Jones’s Moon (2009) strips the moon of all the romance and adventure of NASA’s lunar landings. It is a desolate, companionless, (literally) repetitive, deadly, uninviting place. The moon is above all boring. For the solitary lunar miner clone Sam Bell (Sam Rockwell), space has never been about the extension of human freedom beyond the trap of our planet’s gravity well. Instead, freedom comes via escape to Earth.

Few films have so realistically described so many different threatening ways that the vacuum of space can kill us — the different ways that our technological efforts to contain those threats can still kill us — as Cuarón’s Gravity (2015). Unlike many films where the tension at least partially dissipates, the danger is unceasing until our hero, Ryan Stone (Sandra Bullock), splashes down on Earth and crawls ashore. She is finally safe to breathe without fear of her oxygen ever running out thanks to the marvel of the Earth’s current ecosystem. As we, the audience, feel at this point as though we can finally take a breath as well, Cuarón is telling us through our own physiology that the Earth is the only home we will ever have. In this way, Gravity is one of the most pessimistic of the recent crop of high-realist space dramas about the possibilities of the extension of human civilization beyond the Earth.

The heroes of Interstellar survey three exoplanets that are candidates for a human exodus from a dying earth, but they turn out to be an inhospitable ocean planet, a desolate ice planet, and a barely survivable desert planet. When all appears lost, the hint of some unfathomably advanced alien race saves humanity, but via a wibbly-wobbly, timey-wimey resolution drawing on the work of Nobel Prize–winning theoretical physicist Kip Thorne, we find that the aliens are actually us. While the film does not explicitly investigate the meaning of a lonely cosmos, this appears to be a background assumption.

This shift from the cosmic optimism of a Star Trek or a Doctor Who, and certainly of the days of the Space Race, about humanity’s place among the stars, to a much more guarded stance or even pessimism should be no surprise. This new cosmic realism comes at a vertiginous moment for humanity’s understanding of our relationship to the planet and to the rest of the cosmos.

As far back as the sixteenth century, Italian philosopher and Dominican friar Giordano Bruno argued that the stars above us were in fact stars surrounded by their own system of planets and they too could be presumed to be inhabited (for why would God go to all the bother to create a world, only to leave it empty?) — a theological position known as “cosmic pluralism.” This extension of the Copernican heliocentric model of the solar system that toppled humanity’s place at the center of the universe was of course a heresy.

The science-fiction worlds of television and film often operated according to the same presumption, albeit stripped of its theism, and enjoyed similar gravity to Earth, similar atmospheric pressure and chemistry. This is probably less a willful disinterest in planetary science than the product of it being much cheaper and more convenient to use an abandoned gravel pit as a set than to represent the much more fantastical reality of other worlds. Science-fiction novels, of course, have no such budget restrictions, and thus have always had greater imaginations.

An Excess of Copernican Humility

Nevertheless, all this had been speculation until relatively recently. We didn’t even know for sure if there were any planets beyond our own solar system before the first confirmed detection of an exoplanet in 1992. As of the time of writing, however, there have been some four thousand exoplanets that have been confirmed.

At first, this seems to buttress history’s sequence of Copernican realizations — including the recognition that our sun is just one of billions of stars in the Milky Way, the discovery of other galaxies, the development of the theory of evolution by natural selection — that have repeatedly toppled humanity from the pedestal we thought we occupied, requiring us to be ever more humble. Once again, having found that stars with planets surrounding them are common, we must be ready to admit we are nothing special. As Stephen Hawking put it: “We are just an advanced breed of monkeys on a minor planet of a very average star.”

The question of how uncommon Earth is, and even how uncommon life is, may be resolved as soon as the next decade, when the next generation of telescopes comes online. The composition of the atmospheres of large exoplanets are already being examined via light from stars as it passes through those atmospheres. When a planet crosses, or “transits,” the path of light from its parent star, such starlight gets filtered through the atmosphere, allowing us to analyze the emission and absorption spectra of its gases, including biosignature gases — those that are produced by life such as molecular oxygen and accumulate to levels that can be detected. Right now, we can only do this for Jupiter-size planets, but with larger observatories such as the James Webb Space Telescope expected to launch in 2021, we should be able to perform such investigations for smaller, rocky worlds in the habitable zone that come closer to Earth analogues (although likely still too big to be true analogues).

This is why MIT planetary scientist Sara Seager believes characterization of exoplanet atmospheres is such a profound endeavor: “When and if we find that other Earths are common and see that some of them have signs of life, we will at last complete the Copernican Revolution — a final conceptual move of the Earth, and humanity, away from the center of the Universe.”

At the other end of the cosmic spectrum, from the vast down to the microscopic, biology appears to give us tremendous hope that Seager is right. Extremophile bacteria and other microbes that flourish under conditions of extreme heat, cold, dryness, acidity, alkalinity, salinity, radioactivity, pressure, and the presence of heavy metals are closely studied by astrobiologists, as their habitats may be similar to the conditions on other worlds. Everywhere we look on Earth, we find life. In the last decade or so, researchers have begun to plunge into the deep biosphere — life far below the surface, drilling some 2.5 kilometers into the seafloor and some five kilometers down continental mines and boreholes. This “subterranean Galápogos” is home to an estimated 70 percent of the world’s bacteria and archaea, a realm where the records describing what were thought to be the absolute limits of life on Earth keep getting broken.

Nevertheless, there are researchers who reckon that perhaps this time there has been an excess of Copernican humility.

The announcement in September of the identification of the first habitable-zone planet we know to contain water outside the solar system prompted a flurry of breathless articles reporting the discovery of a supposedly “habitable” exoplanet — and only 110 light-years away, basically next door by astronomical standards (even if it would take a probe like Voyager some 2 million years to get there). But K2-18b is estimated to be almost three times the size of Earth and have almost nine times the mass. It was almost classified as a mini Neptune rather than a super Earth, and perhaps it should have been in order to avoid media hyperbole.

The size suggests it has an extremely thick atmosphere, much of which is hydrogen gas. At its rocky core (if it has one), the pressure from that vast atmosphere would be thousands of times greater than at Earth’s surface, with temperatures hitting 2700°C (5000°F). Under these conditions, as Harvard exoplanet atmospheric specialist Laura Kreidberg has been at pains to stress, complex molecules necessary for life cannot form. Out of all the four thousand, while this is “the best candidate for habitability that we know right now,” according to the researchers, it’s still not habitable, and certainly no analogue Earth.

The infamous Fermi paradox formulated by Italian physicist Enrico Fermi asks: If there are billions of suns like ours in the galaxy, many of which are billions of years older than our solar system, and Earth is so unexceptional, then at least some of these ancient worlds must have achieved advanced technology eons before us — so then where is everybody? Why, when we look up at the stars, do we not see any evidence of this? Why have we not been visited?

Various answers have been proposed, including, most darkly, that once a civilization reaches a sufficiently advanced level of technology, it inevitably wipes itself out, perhaps via nuclear weapons, perhaps by combustion of fossil fuels.

Director of the Columbia Astrobiology Center Caleb Scharf, in his 2014 book The Copernicus Complex, has another explanation. He counters Hawking’s presumption about our mediocrity, noting that, in fact, the sun is not at all very average, and that the architecture of our planetary system in terms of orbits, spacings, and occurrence of types of planets is something of an outlier.

Astrophysicist John Gribbin makes a similar argument in his 2011 book Alone in the Universe, that a chain of improbable coincidences had to occur for intelligent life to exist. Any earlier in the history of the galaxy, and our planetary system would have too few metals to form life. We appear to be not just in the goldilocks zone in our local system but in the galaxy, too: if we were too near the center, it’d be too crowded, with near-sterilizing events such as supernovas and gamma-ray bursts from merging neutron stars more common; if we were too far out, again, the lack of metals would sink us.

The presence of the moon and Jupiter may also play a key role in keeping us safe. Here on Earth, while life got started perhaps just a billion years after the earth was formed, it took 2 billion years between the first emergence of bacterial and archaean life and eukaryotic life (cells with true nuclei), and another billion again before eukaryotes got friendly enough to bunch up into multicellular life.

Compared to the universe’s 13.8-billion-year-old life span so far, 4 billion years for things to kick off hints at how unlikely this may be. And it still took until a bare 550 million years ago during the Cambrian explosion for multicellular life to proliferate into the variety we are familiar with. Gribbin reminds us that we still do not know why this most significant moment in the fossil record happened, and thus how likely it might be anywhere else.

The existence of some organisms with every higher biological complexity does appear to increase over time (in other words, the variance of complexity expands), but the most common type of complexity remains basic: the majority of species are simple prokaryotes. And within our own prehistory and history, there have been a number of unlikely events, including that some seventy thousand years ago, due to some catastrophe, humanity was reduced to just a thousand individuals. Gribbin’s hunch is that simple life may exist somewhere else in the Milky Way, given how rapidly life first appeared on Earth, but we are the only technological civilization in the galaxy.

Of course, there are lots of other galaxies, one might say. But given the vastness of our own galaxy, even this is still rare and precious enough. The point, in any case, is rather that we live in an interesting time, where recent discoveries push in one direction suggesting that life is utterly common and unexceptional, and other recent discoveries push in the other direction, suggesting how rare and precious life — particularly conscious life — truly is.

However, these discoveries by astronomers, cosmologists, and planetary scientists that are filtering their way into popular culture, sculpting our notions of what is believable on-screen, are not the only such influence.

The Cosmic Stakes of Preserving Life on Earth

Here on Earth, our relatively new understandings of ecosystems — new at least since the Space Age — and how humanity is endangering the geologically brief, ten-thousand-year window or so of conditions that have allowed us to flourish, and our even newer understanding of how the human body is an ecosystem itself, a “microbiome,” are surely also prompting the emergence of this new cosmic realist cinema. Certainly, many of these films address directly or indirectly climate change and related ecological challenges. We can see this in the agricultural and extreme weather background of Interstellar, the opening title card of Ad Astra speaking of a time of “hope and conflict,” and, most explicitly, the ecological catastrophe of the Danish-Swedish low-budget but still high-realist Aniara (2018), a melancholic tale of a Mars-bound space-faring cruise ship gone adrift for years without hope of rescue. In the latter, the passengers become addicted to a “holodeck”-like room powered by an artificial general intelligence that feeds them dreams of nature on Earth “like how it used to be.”

And if we are the only self-aware life in the galaxy, then preservation of the ecological conditions that have allowed humanity to flourish suddenly become even more important. We are not merely saving ourselves but saving a universe that is becoming aware of itself. Our series of profound global biocrises immediately have cosmic resonance.

When we think of ecology, we immediately think of external nature, but in recent years, microbiology has shown how each of us is as much an ecosystem, including human cells and microbial cells, a great many of which we cannot survive without, as we are an individual. Ecology and biology increasingly even trouble the notion of individuality, or at least recognize that biological individuality comes in degrees and can be realized at multiple levels, emerging as a product of the coming together of what were previously distinct entities. Our multitudinousness, as science writer Ed Yong puts it, connects us to the wider, global ecosystem not in some abstract or poetic way but directly. In truth, it is hard to make a hard distinction between ourselves and external nature. This, in turn, means that for any extended period of time external to the earth, it is not enough for humans to strap themselves inside one of David Bowie’s tin cans, but rather that we have to take our ecosystems with us, at least in some significant part.

But then how can we create mini ecosystems separated from the earth that are capable of sustaining themselves and thus us in perpetuity? We don’t know yet. Efforts to create complex closed ecological systems have proven extremely difficult.

Kim Stanley Robinson’s remarkable ecological novel disguised as space-based hard science fiction, Aurora, is a thought experiment about such an effort on a grand, generation-starship scale. After seven generations and 160 years, the biomes in the ship begin to break down as the rate of evolutionary change of bacteria and macroscopic organisms is hopelessly mismatched. One walks away from the book confronting the possibility that human colonization of other worlds is somewhere between impossible and formidably more difficult than our earlier science fiction ever imagined.

“There are a lot of people, even powerful, influential people, who seem to think that the goal of humanity is to spread itself,” Robinson says of the ideas behind Aurora. “Maybe there’s only one planet where humanity can do well, and we’re already on it.”

However, the interrogation of Clarke’s dilemma by Ad Astra surely imposes the opposite conclusion to that of Robinson, even if one accepts Robinson’s powerful ecological argument about the profound difficulty of taking our ecosystem with us. On a geological scale, life on Earth may be robust. The planet has passed through far worse than what humanity is currently throwing at it. Instead, it is the goldilocks conditions that support humanity that are under threat as a result of the irrational production incentives of the market. But even a geological scale is puny compared to a cosmic scale. And on a cosmic scale, life on Earth is indeed precarious.

In about 600 million years, the sun’s increase in solar luminosity will set in chain a series of events that will kill off most plants, the support base of much complex life. Unicellular life will then predominate until about 3 billion years from now, and then it too will die out. Thus, the imperative that commands that we preserve and enhance the ecological conditions that have allowed human consciousness to flourish, in other words, to work to prevent climate change and biodiversity loss, also commands us to preserve that consciousness beyond the end of days of the earth, especially if, as Clarke and Ad Astra wonder, we are the sole conscious inhabitants of the galaxy or the cosmos.

We Don’t Need to Choose Between Human Flourishing on Earth and Space Exploration

Born in the year of the first moon landing, director Gray told CNET that he laments the loss of the “tremendous aspirational power” of humankind’s quest for space. Elsewhere, Gray has said that the character of Clifford McBride, obsessed with finding intelligent life, “wasn’t just the ogre — that there was also something beautiful about his dream.” The tragedy of Clifford instead is that “He never found beauty in the idea that human beings are what matter. The idea of striving is what matters.”

“The lunar landing is the greatest achievement in the history of the human race,” Gray says of this striving. “I think we take it for granted now . . . What was lost was the will because the whole vision of space exploration was essentially motivated by the desire to beat the Russians to the moon. And once the United States did that, we stopped caring.”

Gray’s comments are echoed by the protagonist of Interstellar. While that piece of cosmic realism may be despairing about the future of humanity on Earth, it blames this failure not on the hubris of mankind but on our abandonment of audacity. Cooper at one point laments how “We used to look up at the sky and wonder at our place in the stars, now we just look down and worry about our place in the dirt.” The line appears to be what remained after editing of a longer aspirational monologue that was still used in trailers:

We’ve always defined ourselves by the ability to overcome the impossible. And we count these moments. These moments when we dare to aim higher, to break barriers, to reach for the stars, to make the unknown known. We count these moments as our proudest achievements. But we lost all that. Or perhaps we’ve just forgotten that we are still pioneers. And we’ve barely begun. And that our greatest accomplishments cannot be behind us, because our destiny lies above us.

And the response of Mark Watney in The Martian to the harsh indifference of Mars is not to curse his lot, but to recognize how important the work of space exploration and colonization is. At that film’s darkest moment, when Watney becomes all but certain that he is going to die alone on the planet, he transmits a message to his superior asking that she speak to his mom and dad about the role of his work in a vast humanist project: “Please tell them I love what I do . . . and that I’m dying for something big and beautiful, and greater than me. Tell them I said I can live with that.”

That is, this trend of cosmic realism is not only a cinematic representation of an emerging, stark realization about our possible uniqueness in the cosmos, about the universe’s profound inhospitable desolation, and about humanity’s inseparability from our ecosystem. It responds to the psychic destabilization this realization causes not with retreat, but with a renewed commitment to humanity and to space.

Of all these films, Ad Astra is perhaps the most aptly named, taken from the Latin phrase ad astra per aspera, “through struggle to the stars.” Our task in this cosmos, to maintain ourselves and flourish so that the universe will continue to have meaning, will forever be riddled with challenge. The struggle will always continue.