Drake Equation: The Sustainability Filter

by Paul Gilster | Jan 21, 2015 | Culture and Society | 26 comments

There are a lot of things that could prevent our species from expanding off-Earth and gradually spreading into the cosmos. Inertia is one of them. If enough people choose not to look past their own lifetimes as the basis for action, we’re that much less likely to think in terms of projects that will surely be multi-generational. That outcome doesn’t worry me overly much because it flies against the historical record. We have abundant evidence of long-term projects built by civilizations for their own purposes, and while we view pyramids or cathedrals differently than they did in their time, their artifacts show that humans are capable of this impulse. The Dutch dike system has been maintained for over 500 years, and precursor activity can be traced back as far as the 9th Century.

Nor am I concerned that most people won’t ever want to leave this planet. I have no ambition to leave it either, but in every era there have been small numbers of people who chose to leave what they knew to follow their impulses, whether they were explorers, exploiters or zealots. Given the opportunity, I’d say that spreading into the Solar System will happen as small outposts evolve into colonies, and colonies are gradually enlarged by the flow of the like-minded.

Or, at least, it will happen if we get past the L term in the famous Drake Equation, which on the level of technology describes the length of time a civilization can release detectable signals, and on a more profound level may describe the working lifetime of a technological society. It’s this factor that Adam Frank (University of Rochester) looks at in a recent New York Times essay. He’s studying the price we pay for developing a global industrial culture, wondering whether this ‘sustainability bottleneck’ may not account for the Fermi paradox; i.e., the lack of evidence for civilizations around nearby stars in an obviously fecund universe.

Image courtesy of University of Rochester.

Civilizations need energy to operate, and as Frank points out, waste (entropy) is an inevitable part of the process of energy generation. Humans harvest about 100 billion megawatt hours of energy every year, with the consequence that we put 36 billion tons of carbon dioxide into the biosphere. We can assume that other civilizations would face the same issues as they grew. We can also see the vast changes that both Mars and Venus have been through in our own Solar System as perhaps once habitable worlds were gradually transformed by natural processes. We’re beginning to piece together general rules that can help us understand what happens as biospheres change.

Some of this change happens without the mediation of living creatures, and some occurs because of them:

…any species climbing up the technological ladder by harvesting energy through combustion must alter the chemical makeup of its atmosphere to some degree. Combustion always produces chemical byproducts, and those byproducts can’t just disappear. As astronomers at Penn State recently discovered, if planetary conditions are right (like the size of a planet’s orbit), even relatively small changes in atmospheric chemistry can have significant climate effects. That means that for some civilization-building species, the sustainability crises can hit earlier rather than later.

Frank’s interest is in studying sustainability issues as a generic astrobiological problem. You’ll recall that we’ve looked at a paper of his on this idea before (see Astrobiology and Sustainability). Working with Woodruff Sullivan (University of Washington), Frank talks in reference to Species with Energy-Intensive Technology (SWEIT), and argues that we can profitably study not only other worlds but our own previous eras of climate alteration for insight. The research program that grows out of this models SWEIT evolution along with that of the planet on which it arises with a methodology based on dynamical systems theory.

Earth’s own past suggests how complex these interrelationships can be. There was a time about two billion years after the formation of the planet when anaerobic bacteria utterly changed the biosphere by driving up the oxygen content in the atmosphere, a form of what was then pollution eventually becoming an essential for life such as ours. Never mind technology — life itself can be a game-changer. With such principles in mind, Frank and Sullivan are interested in the ‘trajectories’ civilizations take as shaped by the choices they make, some of which could result in population collapse while others lead to long-lived technological societies.

It’s always possible, Frank speculates, that we have a Fermi paradox because no civilization makes it through its sustainability crisis. But there are models that indicate this doesn’t have to happen.

By studying sustainability as a generic astrobiological problem, we can understand if the challenge we face will be like threading a needle or crossing a wide valley. Answering this question demands a far deeper understanding of how planets respond to the kind of stresses energy-intensive species (like ours) place on them. It’s an approach no different from that of doctors using different kinds of animals, and their molecular biology, to discover cures for human disease.

So maybe we’re not the only ones to tackle these problems, which are the consequences of physical laws that govern the interactions between planets and the life they sustain. We don’t have enough knowledge to provide the answer, not yet, but the generic problem is one that advanced civilizations anywhere must at some time face. I leave it to specialists like Frank to discover whether the ‘needle’ or the ‘valley’ is the best metaphor. My own suspicion is that sustainability is a manageable matter, while civilizational collapse through inadvertence via war or accident is the more likely outcome. That’s the filter on L that keeps me up at night.

The Frank and Sullivan paper is “Sustainability and the astrobiological perspective: Framing human futures in a planetary context,” Anthropocene Vol. 5 (March 2014), pp. 32-41 (full text).

Making the Case for Deep Space

by Paul Gilster | Jan 19, 2015 | Culture and Society | 31 comments

I get few questions that are harder to answer than ‘what happened to the sense of adventure that we once had with Apollo?’ And there are few questions I get more often, usually accompanied by ‘how are we going to do starflight if we don’t even have the will to go back to the Moon?’ Both questions have unsettling answers, but the second question is open-ended. We can hope that the ‘sense of sag’ that Michael Michaud describes in talking about the post-Apollo period (for manned flight, at least) may itself evolve into something else, something far more hopeful.

But let’s dwell a moment on the first question. I’ve been looking over an essay Michaud wrote for Spaceflight in the mid-1970s, a decade of the Pioneers and the Voyagers, but also a decade when it became clear that our presence on the Moon with Apollo was going to be a short-lived affair. Instead, we were talking about Skylab, about docking operations between Soviet and American spacecraft, and the next big ticket item on the manned spaceflight agenda looked to be a reusable space shuttle. NASA wanted to deliver measurable returns, even when many of us were thinking ‘Wait! Weren’t we supposed to be headed on to Mars by now?’.

There were plenty of reasons for what some considered to be a more realistic assessment of Earth’s needs. The critics of Apollo argued that it was played as a card in the great geopolitical game of the Cold War, set up as a contest between two super-powers so that achieving the Moon meant the ‘race’ was over. We were dealing with enormous demands on spending, and space projects that could produce quantifiable results were the currency of the day. Instead of manned missions to the Moon, the goal was scientific observation of the Earth to improve our understanding of our ecosystem, to upgrade communications, to streamline navigation.

Nearby Space in Context

To our credit, the exploratory impulse remained, as the Pioneer and Voyager triumphs attest. But are we as a species destined to stay on the Earth or just above it in close orbit, letting our machines be our surrogates in deep space? A prolific essayist and author (Contact with Alien Civilizations (Copernicus, 2007),. Michaud is a former diplomat with global experience in US science policy. He argues here that such a limited view of manned spaceflight goes against the impulse that has long driven us toward expansion. Remember, this perspective is from the 1970s — our ‘sense of sag’ has been with us a long time:

Historically, spaceflight has had a philosophical purpose: to carry man to the stars. From early pioneers such as the Russian Tsiolkovsky and the American Goddard to contemporary writers such as Arthur C. Clarke, there was a consistent line of thinking: build the machines that will allow man to escape the confines of Earth and explore the Universe, and expand the realm of the human race. But military exploitation of the rocket and Cold War competition in space diverted our thinking, and Project Apollo ultimately left us unsatisfied because it had a short-term goal and did not lead directly to anything else. While Apollo proved that man could reach another sphere, it did not leave a step to be built upon.

Image: Saturn V at twilight and, at upper left, its target. Credit: NASA.

I agree completely with Michaud that a major problem with Apollo was the fact that it was in every sense a crash program. The US found itself, post-Sputnik, trying to catch up to a rapidly moving Soviet program that was setting new records in space almost monthly. In fact, looking back at how we pushed the envelope with missions like Apollo 8, I’m astounded that we didn’t lose more than one Apollo crew (and at that, the one we did lose died in a training accident). We put a crew on a never-before attempted journey outside Earth orbit to the Moon and back, launching Apollo 8 with a rocket that had never been used for a manned mission (Apollo 7 flew a less powerful variant of the Saturn rocket). It seemed dicey at the time, but from the perspective of half a century later, it seems like utter folly. The results were, of course, magnificent.

But while we still play Apollo 8’s Christmas Eve transmission from lunar orbit on YouTube and elsewhere, we’re trying to work out the next bold steps for the manned space program in a very tentative way. If Mars is truly our objective, it’s an objective that’s only vaguely in our plans for the 2030s, the kind of goal that all too easily recedes a decade at a time. NASA may or may not complete the Space Launch System, but are we sure what we will do with it? Elon Musk wants to die on Mars — does SpaceX and Falcon Heavy awaken any sort of Apollo-like passion?

Spaceflight and Evolution

For some of us, the old passion never died, but when it comes to the general public, we’re dealing with a case that has to be made all over again. If we take an evolutionary perspective, the purpose of human life, argues Michaud, is survival, as it is for all forms of life. How to broaden our survival options is a question of how we can upgrade our evolutionary potential. From the essay:

The tools for the improvement of our survivability are guided evolution, conflict limitation, a balanced relationship to our Earthly environment, and space flight. The first three can improve our chances anywhere that humans live, but are presently limited to the Earth’s biosphere. Only space flight can give man the option of surviving no matter what happens on Earth, of spreading the human race throughout the universe, of opening up new environments for long-term human evolution.

There’s that phrase again: ‘long-term.’ To engage the public in a program for human expansion into the cosmos is to reverse the Apollo preoccupation with crash programs and near-term wins. A rational program to achieve starflight is not likely to happen against a ticking clock. Rather, it will be an effort that sustains itself philosophically across the decades and centuries such an effort will require, crossing many human generations. It will be an exploratory and expansionist meme that remains alive because its triggers are fundamental to our nature as human beings.

Let me quote Edmund Burke on this, because the views of the 18th Century political theorist and philosopher are much to the point:

[Society] is not a partnership in things subservient only to the gross animal existence of a temporary and perishable nature. It is a partnership in all science, a partnership in all art; a partnership in every virtue, and in all perfection. As the ends of such a partnership cannot be obtained in many generations, it becomes a partnership not only between those who are living, but between those who are living, those who are dead, and those who are to be born. Each contract of each particular state is but a clause in the great primeval contract of eternal society.

Specifically, spaceflight challenges human capabilities and stimulates intellectual innovation. We are forced to develop new techniques, new materials and new forms of cooperation as we engage with a frontier more hostile than any we have known. Yes, these technologies will produce tangible results on Earth, many of which are obvious, from communications to power-generation. Mastering closed biospheres will teach us a great deal about our Earth. But we are also driven on a purely intellectual level to learn more about the cosmos, an engagement that broadens our understanding of physical law and provides context for all our science.

End of the Space Race

A goal of interstellar flight is not reached with a ‘space race’ mentality, although competition can boost interim steps — it will be interesting, for example, to see how the Western democracies react to a potential Chinese presence on the Moon. But the interstellar goal is too big to be comprehended by its individual components. It is a goal that begins in the short-term to expand our presence in the Solar System, reaping rewards like enhanced energy production and access to materials made available through exploitation of asteroids and other resources. There is in Michaud’s view a powerful encouragement to international cooperation in all this, for cutting costs if nothing else. Underlying early expansion is the reduction of existential risk, but also the possibility of diversifying the species as humans in new environments inevitably adapt.

Culturally, there is little to parallel the growth in philosophical perspective that may be gained by interacting with societies beginning to take hold in O’Neill-style colonies or on nearby planets like Mars, just as the Renaissance in Europe was bolstered by the influx of ideas and commodities from voyages of exploration. We might add a SETI imperative as well. If we do one day make contact with an extraterrestrial species, our own development off our world will likely be seen as an evolutionary step that is reproduced elsewhere in the universe. The potential growth in knowledge from such contact emphasizes space-based strategies to maximize the search.

All of these are short-term but necessary goals, each building on the other. But unlike Apollo, the species must have the broader context to work with. As Michaud writes:

Even if funding for major new projects seems unlikely now, interest must be kept alive. Industrial, labour, military, and scientific interests will continue to be important for the future of space flight, but farsighted political leaders also must mobilize public support with the excitement of exploration and discovery, of expansion and new opportunities, of the change in man’s place in the universe. They must hold out the promise of new and better lives, not just for a few astronauts, but for ordinary people.

None of this is easy to sell, but the collapse of interest post-Apollo should not be allowed to take hold as an inevitable consequence of success in space. The argument for a deep space exploration program is one that needs to be made again and again, for public sentiment changes slowly without precipitating events. But interplanetary growth must not become an end in itself. Interstellar flight, as Michaud reminds us, is open-ended. It opens before us an all but infinite frontier. That frontier is woven into our psychological and philosophical DNA as much as it is entwined with our evolutionary need for survival. We must continue to make the case.

The paper is Michaud, “After Apollo,” Spaceflight Volume 15 (October 1973), pp. 362-367.