Centauri Dreams

The problem in sending intentional signals to the stars isn’t technology. It’s our lack of consensus. Having widespread buy-in on whether, why and how to add an ‘active’ component to SETI is deeply polarizing, at least on the surface. But dig deeper: While there are those who think we should send signals about ourselves to other stars, the opposition doesn’t necessarily disagree provided appropriate discussion and consultation be achieved first.

I’m with the latter camp and always have been. To me, this is as sensible as coming up with an environmental impact statement and debating it. We need to be thinking about the issues involved here because as technologies get more powerful, individual actors will be able to send messages that would formerly have been in the province of governments.

As I mentioned last week, such issues are not new to science, as witness the debate over recombinant DNA research that eventually led to multidisciplinary agreement — for more on this, see Asilomar Conference on Recombinant DNA — (and see David Brin’s SETI, METI and the Paradox of Extraterrestrial Life for more). The point is, thorny questions involving research and the limits on action need to be resolved through wide-ranging discussion.

Image: Looking toward the center of the galaxy (itself obscured by dust) from the Chilean Andes. Credit and copyright: Serge Brunier.

These reflections were triggered by re-reading Michael Chorost’s essay How a Couple of Guys Built the Most Ambitious Alien Outreach Project Ever. The topic is the Cosmic Call messaging project that sent two signals, in 1999 and 2003, from the Evpatoria dish in the Ukraine. What’s interesting here is that Cosmic Call didn’t come out of a space agency or a government decision. It came out of a series of interactions between private players.

Chorost is a canny writer, the author of the deeply insightful World Wide Mind (Free Press, 2011) and an active commentator on technology. He followed the Cosmic Call story to its origins in Team Encounter, a Texas-based firm intent on launching a true interstellar solar sail — i.e., a sail dedicated to making a 100,000 year crossing to Alpha Centauri while bearing messages, photographs and even DNA samples from supporters. The sail morphed into a message which would involve drawings, texts and songs from the people of Earth.

This is where Yvan Dutil, a Canadian astrophysicist, came into the picture, contacting Team Encounter with his own ideas about how to put together a message. Dutil teamed up with the late physicist Stéphane Dumas, who began to ponder message ideas based on the work of Hans Freudenthal, who had studied symbolic media of communication. Remember, we have nothing in common with the species we are hoping to contact — we assume a basic sense of logic which Dutil and Dumas explored in the form of a message primer.

I won’t get into the details of the primer itself, sending you to the Chorost essay, but it’s worth noting that Douglas Vakoch (formerly of the SETI Institute, and now a METI advocate and president of METI International) saw in the Dutil/Dumas primer “…a complexity and depth that’s unparalleled in interstellar messages.” Of which there haven’t been many, but you see the point. This two man team had come up with a symbolic system that would allow, so they believed, an alien civilization to receive information, ask questions and respond.

In one way or another (and memories differ on exactly what happened), Dutil and Dumas became aware of the Evpatoria dish in the Ukraine, which led them to Alexander Zaitsev, an astronomer at the Russian Academy of Science whose work with the Evpatoria dish had largely involved planets and near-Earth asteroids. Already passionate about SETI, Zaitsev agreed to a proposal to oversee sending the Cosmic Call messages from the Ukraine.

Chorost likes to call this a ‘crowdsourced’ effort growing out of the dedication of the two scientists who had conceived the message and energized by their dealings with the Cosmic Call group. The effort would grow into a message sent to four stars in 1999 and then five more in 2003, using a transmitter powerful enough to be detectable as far as 70 light years out. But METI was controversial from the beginning, as Chorost relates:

…the National Space Agency of Ukraine, as it was called at the time, was alarmed enough to stop the transmission in 1999 after the message had been sent to the first star on the target list. According to Zaitsev, the agency was rattled by the attention the message was getting from the press. “Such energetic reaction of Western mass media also was an alarming news for Kiev’s officers,” he says. In addition, they had been told that the transmissions were “very dangerous for terrestrials and that USA’s deep space stations refused to make Cosmic Call transmission.” They pulled the plug. Zaitsev rushed to Kiev to reassure the brass, and the transmissions resumed on June 30, 1999.

The point that emerges is that this SETI project, conceived and funded by private organizations, wound up costing something on the order of $100,000, much of it from small donations. Although perhaps 20 people were involved in getting the message sent, the message itself was the work of two people. We can only assume that the costs involved are going to continue dropping, which means that other messages like this one surely lie ahead.

That gets me back to the original issue. The scientific process is all about a common forum of ideas, discussions of peer-reviewed papers, conference proceedings and meetings between experts in the field, with public debate affecting subsequent policy on matters of global import. With METI we are beginning to see significant decisions being taken by individuals without consensus among researchers and without the time for serious public reflection.

Can we find any agreement between the two camps on METI? Douglas Vakoch, a strong defender of METI, asks in a recent letter in Nature Physics whether there are ways of submitting transmission proposals to the scientific process. Let me quote him on this:

Scientists already have a process for judging the merit of METI projects: peer review. Decisions about allocating time for METI at publicly funded observatories should rely on the same procedure used for competing experiments. If proponents can make a convincing case, when compared with other proposals, for effectively using a transmitter for a specific METI experiment, then time should be granted.

There may well be a place for METI in our future, but we need to define and choose it. My own belief is that this needs to go beyond a small peer-review group for a specific project and extend to the entire idea of METI. How this could be done in the era of a global Internet is something that should spur the imaginations of everyone from social scientists to network programmers. However we formalize and codify the discussion, though, technological change forces the issue, making the question of who speaks for Earth more timely than ever.

We speculated yesterday that categorizing civilizations on the basis of their power use may not be a given, though it is the basis of the familiar Kardashev types. It seems natural to a rapidly changing technological society like ours that the trend is always upward, a clear path toward harnessing the energies of the home planet, then the Sun, then the galaxy.

That this may not be the case seems to go against the grain of ‘Dysonian SETI,’ which looks for, among other things, artifacts as large as Dyson spheres and other astro-engineering projects on massive scales. Or maybe not, for some engineering involving adjustments to planetary environments may well produce observables. We just have to be aware of the range of possibilities here, and recognize our own limitations in trying to figure them out.

For we’ve learned something else from technology, and that is that its components grow ever smaller. Working at nanotech scales to create things from the ground up isn’t beyond the imagination, and engineering that recedes into the background so as not to be visibly apparent is even now gaining traction. The kind of voice recognition and rudimentary intelligence built into my Google Pixel hides its complexities in a small package. I speak into the air and tap the resources of computer clusters that are located who knows where.

What would a stable, space-faring civilization that has gone through its own version of the Anthropocene and reached a societal maturity look like when viewed from afar? Working these themes in Earth in Human Hands (Grand Central, 2016), David Grinspoon is anxious to reconcile our human activities through technology with the long-term survival of the planet, an outcome he believes, with a refreshing optimism, is likely to occur.

As we’ll see, it’s also an outcome made possible by going off-planet, for we cannot turn our back on the technologies that have the power to transform and heal our world. These invariably involve studying our globe with new space-based tools and analyzing other planets to understand what can go wrong and right about planetary evolution. So the question becomes, how does a civilization get through its early stages to harmonize its technologies with the planet that gave it birth, becoming a ‘planetary intelligence’? And from the SETI perspective, how would we go about finding a civilization that had succeeded?

A Different Kind of Biosignature

We’re entering the era when space-based resources will be able to analyze the atmospheres of exoplanets, looking for the kind of imbalances that suggest constant replenishment in a life cycle of some kind. The same technologies allow us to look for what we can call ‘technosignatures,’ which are signs not just of life but of a civilization. One way to look at this is through terraforming, the adaptation of a planet to make it hospitable for living beings. Grinspoon believes that we will eventually be terraforming our own world, in the sense that we will acknowledge the need to engineer and reverse ecological damage and emissions.

Image: Can we detect not just biosignatures but signs of technological civilizations through analysis of an exoplanet’s atmosphere? Credit: IAU/L. Calçada

One thought is to look for signs of imbalance suggestive of technologies like ours, producing air pollution that can be measured by spectroscopic analysis. Because we don’t know what we may eventually stumble across, it makes sense to study the potential signatures of a planet in transition. I can point you, for example, to Henry Lin (Harvard), who in collaboration with Gonzalo Gonzalez Abad and Abraham Loeb has produced “Detecting industrial pollution in the atmospheres of earth-like exoplanets,” a paper published in the Astrophysical Journal Letters (Volume 792, Number 1 — preprint here).

The authors of the Lin paper are interested in anthropogenic pollution as a technosignature (though they don’t use the term), a marker of intelligent life and technology. It turns out that the James Webb Space Telescope will be capable of picking up atmospheric tetrafluoromethane and trichlorofluoromethane, which are the easiest to detect chlorofluorocarbons produced by industrial activities. But Lin et al. are talking about detections involving Earth-like planets transiting white dwarfs and levels of pollution ten times as strong as Earth’s.

Even so, this gets intriguing. One thought is that a civilization in a highly polluted environment is transitory — it is either going to solve its contamination problems or else go under, and this must occur in a tiny window on the scales of astronomical time. But perhaps there is another possibility, as the paper argues:

Coupled with the fact that the half-life of CF₄ in the atmosphere is ? 50, 000 years, it is not inconceivable that an alien civilization which industrialized many millennia ago might have detectable levels of CF₄. A more optimistic possibility is that the alien civilization is deliberately emitting molecules with high GWP [global warming potential] to terraform a planet on the outer edge of the habitable zone, or to keep their planet warm as the white dwarf slowly cools.

Now we’re hunting a terraforming signature, an environment being deliberately manipulated. David Grinspoon points to this kind of signature as a more enduring observable:

If we find an exoplanet with a strange climate that is being controlled by unexpected atmospheric compounds such as chlorofluorocarbons, that should get our attention. Or if we find a world with a suspiciously unusual pattern of albedo (reflectivity) or day/night pattern of brightness, we might suspect planetary engineering with mirrors or surface alteration. We should take notice if such a world seems to be in a climate state that preserves or extends an early evolutionary stage, stabilizing against the aging of its star.

Global engineering on a scale that would ward off, say, a runaway greenhouse should throw a signature; it’s our job to figure out what it would be, on the off chance that we someday see it. It’s clear enough, and Grinspoon makes the point repeatedly, that we can’t anticipate what advanced alien societies are going to do, so maybe the best approach is to be on the lookout for what we can call ‘unnatural’ planetary states that tip us to some kind of management. This theme — that we have to avoid being doctrinaire because we are bringing all too human judgments into matters that involve aliens, about whom we know nothing at all — is significant not just for analyzing our SETI observables but for extending SETI into other arenas.

Signaling to the Stars

There is a photo in Earth in Human Hands that shows author David Grinspoon standing with Alexander Zaitsev, who was chief scientist at the Russian Academy of Science’s Institute of Radio Engineering and Electronics, and whose name has become synonymous with broadcasting to the stars. Zaitsev has, in fact, been the driver behind several messages beamed from Earth as a deliberate attempt to raise the interest of any nearby civilizations. In 1999, the first Cosmic Call message was transmitted to four different stars, with a second Cosmic Call sent out in 2003 to five Sun-like stars between 30 and 45 light years away.

Long-time Centauri Dreams readers know that Dr. Zaitsev was a frequent contributor to the comments in these pages as the discussion over so-called METI (Messaging to Extraterrestrial Intelligence), also known as Active SETI, flared into life. And I do mean ‘flared’ — nothing polarizes people more than the question of whether or not we should deliberately brighten our radio signature with such targeted messages, given that we know absolutely nothing about what kind of alien civilizations may exist. It’s ‘shouting into the dark,’ at a time when we don’t have a clue what may be out there.

David Brin was also a frequent participant in those discussions, which often referred to the 1983 Brin paper “The Great Silence” and speculated on reasons why advanced civilizations might want to keep a low profile. While METI proponents argue that reaching out to announce our presence is a means of exploration, and one that is necessary because if all civilizations are listeners, there will be nothing to receive, the Brin contingent argues that inclusive international discussions are needed so that we make this decision by consensus.

Image: At the heart of the Messier 13 globular cluster in Hercules, toward which a simple pictorial message was sent from Arecibo in 1974. Credit: Credit: ESA/Hubble and NASA.

This is a serious debate with a history that I don’t have time to get into this morning other than to say that Grinspoon’s book presents the background. There is plenty to talk about — the development of guidelines for Earth broadcasts at Valencia in 2006, a strong editorial response in Nature, the resignation of Michael Michaud and John Billingham from an IAA SETI study group because of changes to the Second SETI Protocol, the AAAS session in San Jose in 2015 — and the often acrimonious debate continues to flourish.

Brin has often held up the ‘Asilomar process’ as a model. The reference is to the agreements within the DNA research community to work out voluntary guidelines for experiments and containment procedures, while banning particularly dangerous experiments involving hard to contain pathogens. The Asilomar guidelines became incorporated into laboratory practices as the field of biotechnology began its growth. It was a form of self-policing that effectively kept research alive while minimizing associated risks. Can we adapt such a process to METI?

METI is filled with arguments and counter-arguments, most of which have been rehearsed in these pages many times over. But I found Grinspoon’s take on the matter refreshing because he’s one of the few involved in the debate who have actually changed sides over time. Beginning with a position not so far from Alexander Zaitsev’s, that SETI demanded both a listening and a sending component, Grinspoon now says he is swayed by those who advocate caution and a moratorium on broadcasts until the matter can be fully assessed.

I’m taken with the fact that the author stresses how much we don’t know. It’s easy to use our human experience to generalize about what aliens might do, something that occurs all the time in discussions on METI. How likely is it that an alien culture would see us as a threat? How reasonable is it to assume that an advanced civilization will have given up war? Shouldn’t we expect a species more advanced than us scientifically to be morally advanced as well? Wouldn’t they, in fact, be inclined to help us elevate our own society to their level?

Grinspoon has been down this road, and he goes through these are other reasons why broadcasting to the stars could be beneficial. But the reasons simply aren’t enough:

Still, I must also admit that these are just my opinions, semi-informed at best. We absolutely can’t know any of this. Maybe it’s all wishful thinking. There certainly are logically valid arguments for the possibility of great dangers. So how do we proceed, if the risks seem absurdly low, but the cost of being wrong is everything we have, everything we love?

Which means that the author remains in favor of active SETI but only with appropriate precautions, and supports a voluntary moratorium. His thinking ties in with the long-term perspective — a millennial outlook — that informs his discussion of geoengineering. We have vast amounts to learn, in other words, about climate before we ever think of active terraforming, either here or somewhere else. Similarly, we need global buy-in to a project like METI that, to be successful, will doubtless also need to operate on long timeframes.

…I would submit that lack of self-knowledge is an existential risk. It may well be that the greatest value of METI will come not from anything we learn in response to a message we send, but from what we learn about ourselves in the process of attempting to reach some common ground and find our global voice. If we decide to send a message to possible extraterrestrials, we are also sending a message to our descendants. We are gifting them with possibilities of both benefit and harm. Such an endeavor requires us to form an alliance with future generations, to enter into a common project with them. That is clearly something we need to learn how to do. So, then, starting the conversation about whether to broadcast, the effort to have a globally inclusive process, becomes a worthwhile goal in itself.

Tomorrow I’ll wrap up this discussion of Earth in Human Hands with the question of sustainability in the context of space. Is a civilization that is working long-term in ways that are hard to spot by our SETI methods one that is invariably planet bound? The answer is no, and we’ll talk about this in terms of interstellar travel. Also in coming days, I want to look at Caleb Scharf’s thoughts on how alien life may prove indistinguishable from physics. More anon.

Have we, as some have argued, entered a new ‘age of humanity,’ the so-called Anthropocene? The notion is controversial in many quarters, but it addresses the growing concern about our human influence on the Earth and the nature of planetary change. David Grinspoon’s new book Earth in Human Hands (Grand Central Publishing, 2016) has much to say about the Anthropocene, but as anyone who has read the work of this canny scientist knows, he’s not one to let facile assumptions get by unquestioned.

For if the activity of humans is now emerging as an agent of geological change, then we are discussing our civilization in the same terms we talk about planetary forces like tectonic movement and the carbon cycle. This makes us major players whose effects we can begin to chart in terms of the effects of our technology on Earth’s living systems. If the Anthropocene is happening, it presents us not only with danger but the prospect of a long-term future. And its implications take in not just our movement into space but our search for other civilizations.

Hence Grinspoon’s view that while we are leaving an unmistakable footprint on our planet’s living substrate, this is not something to be deplored as much as understood and put to good use, the theory being that living things have always shaped the world around them, in ways as profound as the Great Oxygenation Event of 2.5 billion years ago. Earth in Human Hands is rich in discussion of what it would be like to enter what Grinspoon calls the ‘mature Anthropocene,’ in which humans acting wisely and with long-term horizons learn to use technology to repair past damage and introduce a new era of planetary stability.

In this view, our current dilemma is that we are achieving global impact without any sense of global control. The analysis is filled with Grinspoon’s experience as an astrobiologist and it draws together themes that are at the heart of how we consider our own future and how we look at other civilizations. For make no mistake, when we examine SETI, we’re forced to address questions like the lifespan of a technological civilization. If such societies persist, how do they do it, and equally of interest, what sort of signature would they leave? Stanislaw Lem comes to mind, and Grinspoon quotes him from his Summa Technologiae:

We need to overcome the habit of considering outcomes of human activity as more imperfect than those of nature’s activity — understandable as such a habit may be at the current stage of development — if we are to talk about what is going to happen in a faraway future.

Are we not ourselves a part of the nature we study, and rather than deploring the fact, should we not be considering how to make our own contribution to the mindfulness that intelligent life brings to the universe? You may pick up a bit of Sagan in these themes, particularly the Sagan (and Shklovskii) of the 1966 masterwork Intelligent Life in the Universe. The connection is borne out by Grinspoon’s relationship with Sagan, who worked with the author’s father at Harvard and shaped his boyhood and early career. No wonder Sagan and Shklovskii’s influence on SETI play such a vital and entertaining role in his book.

A Third Route for SETI

A confluence of events marks the beginning of SETI, with Frank Drake’s early efforts at Project Ozma following swiftly after the famous “Searching for Interstellar Communications” paper by Giuseppe Cocconi and Philip Morrison. But I think you could say that the discipline put down its formative roots at two conferences, the first being the one Drake hosted at Green Bank in 1961, the second the First All-Union Conference on Extraterrestrial Civilizations and Interstellar Communication, which was held in 1964 at the Byurakan Astrophysical Observatory in Soviet Armenia. Between the two we see a foundational SETI defined.

Frank Drake’s famous equation emerged from Green Bank, a conference with only 11 attendees that took SETI out of the realm of theory and into observational science. At Byurakan, Iosif Shklovskii criticized the Cocconi and Morrison paper for being too restrictive — the authors, Shklovskii argued, assumed that extraterrestrial civilizations would be on approximately the same level as ourselves. Shklovskii believed that any civilizations we detected would be far more advanced technologically than ourselves, for “We are only infants as far as science and technology are concerned,” and technology’s growth is rapid.

Grinspoon’s treatment of SETI is relaxed and knowledgeable, but it is the weaving of the anthropocene theme into SETI’s subsequent development that gives these chapters punch. For Nikolai Kardashev, then a young student of Shklovskii’s, was also at Byurakan to make the case for his three types of technological civilization, based on what he saw as a predictable and steady increase in the use of energy. Thus the categories most Centauri Dreams readers have come to be familiar with:

Type I: A civilization that can use all the energy resources of its own planet.

Type II: A civilization using all the energy resources available from its star. This is a civilization that has mastered its own stellar system and travels readily in space.

Type III: A civilization that can harness the energy of its entire galaxy. This is obviously an interstellar culture that moves freely between stars.

Image: Astrobiologist and author David Grinspoon, now a senior scientist at the Planetary Science Institute in Tucson.

We have often considered in these pages how advanced civilizations might present themselves to a distant observer; i.e., what kind of signature their engineering might leave in star systems and, indeed, in entire galaxies. Searches for Dyson spheres and odd stellar phenomena like the light curves of KIC 8462852 (Boyajian’s Star) continue to push the boundaries of radio and optical SETI. At a second conference in Byurakan, put together by Sagan and Shklovskii following the success of their book, the discussions of advanced technologies clustered around the Kardashev scale and its potential observables.

Radio and optical SETI, the first level of SETI, are complemented by a Dysonian SETI (level 2) that looks through our astronomical data for the signs of technological activity. But Grinspoon points out the key assumption of the Kardashev scale: That civilizations will inevitably increase their energy use in order to fuel a continuing expansion into the cosmos.

This is an idea of progress that is generally accepted — Grinspoon calls it the ‘inevitable expansion fallacy’ — but it is one that doesn’t take into account that key term (L in Drake’s equation) about the lifetime of a technological civilization. What if, in short, expanding in the Kardashev manner is the most likely way to end the growth of a culture?

A third level of SETI now emerges. You can see how Grinspoon is tying this back into the idea of an Anthropocene epoch on Earth. Let me quote him on this:

…it is reasonable to suppose that truly successful, long-lived species have all discarded the expansion imperative, and replaced it with an ethic of sustainability, of valuing longevity of expansion. If technological intelligence has a true and lasting form, one of its basic properties must be that it moves beyond the exponential expansion phase (characteristic of simple life in a petri dish or on a finite planet) before it hits the top of the S-curve and crashes. For us, achieving this kind of planetary intelligence will require critically examining our inherited biological habits and shedding those that have become liabilities.

And what exactly does a planetary intelligence involve? Grinspoon explains it as:

…thoughtful control over one’s self, escape from the mindless drives to multiply, to expand, to lay waste, kill, and drown in your own waste. Perhaps this is why we will not find what Shklovskii called ‘miracles,’ the highly visible works of vastly expanded super-advanced civilizations. Because advanced intelligences are not stupid.

At this point, we’ve stood Kardashev’s ideas on their head, for what Grinspoon is saying is that the kind of technological intelligence that lasts is one that has the ability to overcome its biological need for exponential growth. If this is the case, then we are confronted with the possibility that the more advanced a technological civilization becomes, the less likely we will be to distinguish it from natural phenomena. We may confront a cosmos rife with advanced civilizations whose work is so harmonized with their surroundings as to be invisible.

In earthly terms, the ‘mature Anthropocene’ is where we begin to move out of the era when the changes we make to our planet are beyond our comprehension, and into the era when we begin to consciously shape the Earth’s future, a time when, as Grinspoon writes:

…we fully incorporate our uniquely human powers of imagination, abstraction, and foresight into our role as an integral part of the planetary system. The mature Anthropocene differentiates conscious, purposeful global change from the inadvertent, random changes that have largely brought us to this point.

In SETI terms, consider the Anthropocene a metaphor for what can happen on other worlds. As we first confront the danger of technological over-reach in our environment and then learn to heal the wounds that limit sustainable growth, we may turn toward a balance that sustains our planetary ecology while ensuring the survival of our civilization. What Grinspoon calls the ‘Sapiezoic’ eon would be the long-lived stage of technological civilization that leads conceivably to immortality. Exponential expansion may simply be an evolutionary dead end, and the likelihood of finding civilizations that are learning this lesson the hard way is vanishingly small. They are simply not in existence long enough for us to see them.

Do we have a chance at detecting a civilization that operates according to the long-term model? Let’s talk about that tomorrow as we continue to look at this third route for SETI. We’ll also see that in Grinspoon’s view, expansion into space has a major role to play in the survival of long-haul civilizations. Developing a stable relationship with world-changing technologies is the key.