Whether On This World Or Others, Our Species Will Someday Perish

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The Course of Empire, Desolation. Credit: Thomas Cole

Elon Musk wants to be humanity’s savior.

Now, I can’t read the SpaceX founder and CEO’s mind and I don’t have any special insight into his thought process. Nevertheless, his public statements lead me to believe that he wants to secure his place in the record books as the person who delivers our species from annihilation.

The most recent statement in this regard came during Musk’s widely-reported speech unveiling his architecture for bringing humans to Mars. It was an exciting talk, and even President Barack Obama thinks it’s time to send people to the Red Planet. While many aspects of Musk’s plan have been dissected at this point — its optimistic timescale, its blind spots regarding basic human biology or planetary protection — I’d like to focus on the opening statements, during which the tech billionaire mused about the course of history.

“I think there are really two fundamental paths. History is going to bifurcate along two directions: One path is we stay on Earth forever, and then there will be some eventual extinction event,” he said. “The alternative is to become a space-faring civilization and a multi-planet species, which I hope you agree that is the right way to go.” (At the point, the audience failed to understand that they were supposed to applaud Musk’s insight, and he had to cajole them to receive some ovation.)

Musk is merely the latest idea man in a long tradition of speculators thinking about humanity’s space-based immortality. Extinguishing existential risk is a commendable desire but rarely do these conjectures go into much detail. Setting up a back-up civilization elsewhere might reduce our chances of extinction by some amount; the question is how much. And even if we settled on more worlds and continued slashing the odds of us being snuffed out forever, could we ever actually reach zero? Perhaps science can help clarify some of these imponderables.

Probably the least-well-understood factor in the Drake equation, which evaluates the number of intelligent aliens we can communicate with, is called L, the average lifetime of extraterrestrial civilizations. Guesstimates — and that’s all we have to go on at this point — range from hundreds to billions of years. But most of the people who’ve thought about the term have been poorly trained in social science and history. There actually exists a wealth of data to mine regarding how societies evolve, grow, and perish. The problem is that none of this information fits into a simple narrative and the conclusions that can be drawn are not necessarily the ones we want to hear.

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Et in Arcadia ego. Credit: Nicolas Poussin

The idea that the starry heavens will provide our species’ salvation can be traced back to the 19th-century Russian mystic Nikolai Fyodorov. A central feature of his philosophy, Cosmism, was what he believed to be humanity’s destiny: traveling out into space to collect the scattered particles of our dead ancestors, reassembling and resurrecting everyone who had ever existed, and then living forever in harmony off- world. Nowadays it’s easy to deride this vision but Fyodorov influenced many later luminaries, including Konstantin Tsiolkovsky, discoverer of the rocket equation.

In laughing at the past, we should keep in mind the contradictions and absurdities in our modern-day thinking about this subject. When it comes to reasons for settling on other planets, the oft-repeated aphorism in the space community is that you shouldn’t put all your eggs in one basket. It’s a sensible strategy but we have to still appreciate its shortcomings. The other baskets that people are proposing — like Mars or the moons of the outer planets — aren’t exactly comfortable little nests of fluff. Each suffers from multiple non-ideal features such as a lack of breathable atmosphere, intense radiation, poisonous soil, or weak gravity.

It’s a little like saying, “We have this basket made of barbed wire here on Earth. Just to be safe, let’s also put one of our eggs in this basket made of fire, this other one in a basket infused with smallpox, another in a basket containing hungry sharks” and so on. Musk and others propose terraforming, making other worlds more Earth-like, as a solution. But that carries a huge number of unknowns and ethical quandaries and may one day sound as fantastical as Fyodorov’s plan to reassemble particles into living people. Even if terraforming works, the existential risk we face on our planet doesn’t magically disappear. Any world we go to will have an expiration date and, one by one, they will be reached.

Okay, you say; forever is a long time and nobody’s really asserting that we need to stick around for infinity years. We just want to last longer than the expected lifetime of civilization on Earth. In that case, the question becomes: How long are we supposed to endure here in the first place? And the answer is: Nobody knows.

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Stanford Torus Cutaway view. Credit: NASA

Back in the 1960s, radio astronomer Frank Drake was trying to come up with a framework for thinking about communicating with extraterrestrial intelligence. An obvious starting point was wondering just how many other advanced civilizations might be capable of accepting our calls. The final term in the Drake Equation, L, can make or break the estimate. A high number for L — meaning that space-faring civilizations last on average a long time — increased the chances that we will overlap with some other intelligent beings.

Ever the optimist, astronomer Carl Sagan maintained that, as long as they didn’t destroy themselves first, the lifetime of civilization was likely to be measured in hundreds of millions or even billions of years. At the other end of the spectrum is science writer and professional skeptic Michael Shermer who penned a 2002 Scientific American essay in which he pulled out a history book and a calculator. After adding up the lifespan of 60 past societies including those in Mesopotamia, Egypt, ancient China, Japan, Africa, Central and South America, and several modern European and American states, Shermer concluded that civilizations last an average of 420 years. Moreover, he said that modern civilizations (those after the fall of Rome) lasted on average only 305 years.

Actually, both types of thinking are misguided, albeit in different ways, says anthropologist Kathryn Denning in her 2005 paper “L on Earth.” Denning finds Shermer’s derivation rather reductive, overlooking any other useful information that could be learned from past civilizations regarding their structure, growth, and demise in favor of a single numerical quantity. At the same time, Sagan’s approach contains a large amount of questionable assumptions and biases that, as an anthropologist, Denning would prefer to unpack.

Historians and anthropologists of the 1800s are responsible for coming up with the notion that all societies progress through similar stages of savagery, barbarism, and, ultimately, civilization. Which, in that case, meant Western European civilization looking much like their own. “There is a sense of entailment here, of a necessary movement from one stage to the next — the framework seems to be an essentially unilinear model of social evolution,” writes Denning.

Later anthropologists had to give up this progressive model because it doesn’t really match reality. Specific technologies such as writing or the wheel are not stages that will automatically be reached. Past civilizations have done just fine without them. Rather than trying to slot all societies into simple frameworks, contemporary anthropology tries to acknowledge their diversity and their struggles to deal with the unique complexity of issues in their own time and place.

Still, this idea of passing through obligatory technological stages holds sway in much of the public’s mind. It comes up in Sagan’s assertion that all civilizations will pass through a “technological adolescence” in which they will be faced with dilemmas that could destroy them. If they survive, according to Sagan, these societies will have displayed their maturity and thus be able to spread into the universe and persist a long time. While this is certainly a possible path, it’s not the only one. We can just as easily imagine civilizations that repeatedly make the same mistakes over and over, always facing new crises, without ever seeming to learn. A thousand other trajectories are also possible — reducing these to a single pathway is like saying that from the moment our ancestors first sharpened one rock against another, their future was already written in stone.

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Credit: Daniel Schwen

Sagan, much like the rest of us, is also biased in a particular direction when it comes to thinking about civilization. “Most modern humans live in complex societies and think that their way of life is normal,” writes historian George Basalla in Civilized Life in the Universe. “In fact, civilized societies are in anomaly. Anthropologist Robert Carneiro estimated that 99.8 percent of human history was dominated by small independent bands of foraging people. Complex societies, in the form of civilizations, have been with us for about six thousand years.”

Denning strikes a similar note discussing the way we believe that only a destructive war, terrible disease, or asteroid impact could cause us to abandon our energetically consumptive and complex modern civilization. “Embedded within this is the notion that the only rational process for a society, once it has achieved technological status, is to keep going,” she writes. Yet we can also foresee a day when the logical decision may be to downscale our technology for the sake of being more sustainable. We might even consider this a successful adaptation to changing conditions rather than a catastrophe.

Civilizations are complicated beasts. They require millions of moving parts and incredible organization. Though they appear stable, they are in fact rather fragile, as Shermer’s lowball estimate for L acknowledges. “Despite the apparent success of civilizations, their complexity makes them vulnerable to collapse,” writes Basalla. “At a critical point, they dissolve into smaller units and lose their power of expansion. Other forms of social organization, with different political, social, economics, and technological bases, eventually replace them.”

How might this process play out on other worlds? What if it were to happen on Mars, a place where humans will depend on technological assistance to keep them alive for hundreds if not thousands of years? I don’t know–and I don’t think anyone else does either.

Elon Musk would like us to believe that he can see the correct path forward. But at this point, his vision is little more than a story. Like all stories, it contains some elements of truth. And like all stories, it’s ultimately just something we made up.

This story was originally published on the defunct website now.space on 10/20/2016

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