Chapter 10: Who Speaks for Earth?

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Take me to your leader!
   ---Plea of a thousand cartoon aliens

SHOUTING AT THE HEAVENS

Imagine that the day has arrived. Humanity has received a message from an alien civilization, directed at Earth. The message has been decoded and the aliens are asking for contact. Should we respond? If so, what do we say? Above all, who speaks for Earth?

The SETI Post-Detection Taskgroup has already begun to wrestle with these thorny problems, for the simple reason that some people have jumped the gun and begun transmitting messages anyway, a practice known as active SETI or METI (Messaging to Extraterrestrial Intelligence). Radio METI began in earnest in 1974, when the Arecibo radio telescope was employed to transmit a message to the M13 globular cluster of stars 25,000 light years away. A more recent attempt was made in 2009 when a large radio telescope in the Ukraine was used to beam fifty photos, drawings and text messages at the planet Gleise 581C, located twenty light years away. The target is one of a handful of newly discovered extra-solar planets thought to be capable of supporting life.

Some people are implacably opposed to METI on the grounds that broadcasting willy-nilly into space, deliberately attracting attention to ourselves, is reckless. An obvious fear is that advertising the existence of our wonderful life-supporting planet might invite an alien invasion. A leading critic of METI is the writer and commentator David Brin, who coined the phrase ‘shouting at the cosmos’. He is dismayed by the happy-go-lucky attitude of a new generation of SETI fans, especially those from the former Soviet Union, who advocate greatly expanding the METI programme in an ad hoc manner without much forethought or attempt at debating the issue. And it’s true that METI attracts far more attention than SETI, primarily because something actually happens---a message is sent! By contrast, all SETI astronomers do is passively listen. METI is popular with young people when the content of the message is opened up to the public; the recent Ukraine transmission followed a competition launched via a social networking site called Bebo, which boasts 12 million users. Brin’s position is that prudence should prevail over popularity. He has called for an international protocol that asks for all of those people controlling radio telescopes to ‘forbear from significantly increasing Earth’s visibility with deliberate skyward emanations, until their plans were first discussed before open and widely accepted international fora [his italics]’. His sentiments have been strongly endorsed by David Whitehouse. 'If we don’t know what’s out there,' writes Whitehouse, 'why on Earth are we deliberately beaming messages into space, to try and contact these civilizations about which we know precisely nothing?'

Champions of METI, such as Alexander Zaitsev of the Russian Academy of Sciences, dismiss Brin’s concerns. They point out that we are already broadcasting. Our radio and television programmes are sweeping across the galaxy at the speed of light: we can’t get them back. A sufficiently sensitive antenna could detect them, and our cover would be blown. However, as I mentioned earlier, our TV transmissions are actually exceedingly weak. Military radars pack much more punch, as do the occasional radar pulses directed at planets and asteroids for scientific purposes. But these beams are sporadic and narrow; ET could easily miss them. So all in all, there is a good chance we have so far escaped detection (by radio at least) even if the galaxy has legions of alien civilizations armed with enormous radio antennas. No doubt this debate will rage for a while yet, but it seems to me largely irrelevant, because whatever scientists and commentators may think, the reality is that a motivated millionaire can build a radio telescope and blast the heavens to his heart’s content, and there’s very little anyone can do about it. METI cannot realistically be policed---at least, no international agency able to do so has the slightest interest in the subject one way or the other.

I am clear in my own mind that the danger from METI is minuscule. Fear of the unknown is understandable, but if we always wait until we are sure there are no demons lurking in the dark we would never do any science and never explore our world. Prudence is wise, but prudence should not mean paralysis. We need to ask why aliens would be interested in harming us or invading. If Earth is attractive as a potential alien habitat, the aliens will know this already without our help. Evidence for oxygen, water and plant life can be obtained spectroscopically from a great distance, even with foreseeable human technology. So we are right back to the Fermi paradox: if they were going to come here for our planet---as opposed to us---they would have showed up long ago. In any case, our radio messages are irrelevant if the planet is what they want. The only additional information to be gleaned from radio communications is that Earth also hosts intelligent life capable of building radio transmitters. Some people worry about enslavement, but that is foolish. A technological community advanced enough for interstellar travel is hardly going to have a labour shortage. It could more easily build robots or bio-machines to do the necessary grunt work. We might conceivably be regarded as a cultural resource or a biological curiosity, and therefore worth preserving. If so, there is no danger. The concern I voiced in Chapter 8, that humans might be duped into building a hostile alien from genetic instructions, is not relevant to METI. That scenario would need careful consideration only if we receive a meaningful message from them.

The greatest danger to humanity is if a nearby alien community judges us to be a threat. Given our warlike history, that is not an unreasonable conclusion. The aliens might decide to mount a pre-emptive strike for the greater good of the wider galactic community. And could we blame them, given that some of our own governments have used precisely the same logic against perceived terrestrial enemies? If twenty-first-century human democracy is anything to go by, it may require no more than a thin pretext for extraterrestrials to ‘take out our weapons of mass destruction’. But even if this gloomy assessment is correct, METI would not increase the risk of bringing fire and brimstone down on us. In fact, it may serve a useful purpose if we could signal our best intentions to ET, in spite of our penchant for warmongering at home. Just how we could convince aliens that we wouldn’t try to blow them away with our missiles and nuclear warheads is another matter. Such a message would in any case be a lie. Humans have fought each other for millennia over tiny differences in race, religion or culture. Imagine how most people would react to beings that were truly alien---not only a different species, but a different life form altogether, with unknown motives and non-human feelings. Fear and revulsion could well provoke a shoot-first-ask-questions-later response. My personal message to ET is to ‘Keep well clear and defend yourself’, before stepping into the hornets’ nest of our militaristic society. I hope such a warning would be regarded in itself as sufficiently altruistic to avert a pre-emptive strike.

I am in favour of METI, not just because I think there isn’t a snow-ball’s chance in hell of anyone out there picking up the signals, but because the act of designing and transmitting messages to the stars serves many noble purposes, such as raising interest in science in general and SETI in particular, and in encouraging people---especially young people---to think about the significance of humanity and the vastness of the universe, and to reflect on the common factors among our disparate cultures that we wish to preserve for posterity. METI is good for humanity and almost certainly completely harmless, given the infinitesimal chance that randomly beamed signals will ever be detected by a malevolent alien civilization.

WHAT SHOULD WE SAY?

In the present context, METI is little more than a harmless stunt. The situation would be dramatically different, however, if we had actually located an extraterrestrial civilization. In that case, it is essential that wiser counsels prevail. Item 7 of the IAA’s Declaration of Principles ‘Concerning Activities Following the Detection of Extraterrestrial Intelligence’ enshrines the need for caution:

No transmission in response to a signal or other evidence of extraterrestrial intelligence should be sent until appropriate international consultations have taken place.

Unfortunately history gives me very little confidence in the efficacy of ‘international consultations’.

On the matter of who gets to respond ‘officially’, I foresee all sorts of problems. A message concocted by a committee would be a recipe for the lowest common denominator, and is likely to consist of banalities. A statement solely by a politician or religious leader is too horrible to contemplate. A potpourri of comments, where each cultural group has its say in the interests of equity or democracy would most likely be judged an incoherent muddle. This sort of pointless gimmick was tried in 1977, when the two Voyager spacecraft, which were going fast enough to leave the solar system, carried identical phonographs. The records convey greetings in fifty-five languages, bird and animal sounds, a selection of music ranging from string quartets to rock and roll, and sombre written statements from others. If ever aliens were to chance upon Voyager drifting in interstellar space, I dread to think what they would make of it all.

Could scientists improve on this? On my office wall hangs a fine plaque, presented to me by NASA. It is a replica of the ones conveyed aboard the spacecraft Pioneers 10 and 11. Pioneer 10 was the first man-made object to leave the solar system, so NASA thought it would be a nice, albeit futile, gesture to convey a message to aliens. As a symbolic act, it is a great idea, and I am proud to possess a replica. My beef is not with the gesture itself, but the content.

The plaque was designed by various people, and shows a picture of a male and female form, one with a hand raised in greeting, together with an image of the spacecraft and some technical data. A line symbolizes the trajectory of the spacecraft showing it originating on the third planet from the sun. Our galactic coordinates are encoded in a clever way, by showing the locations and frequencies of a set of pulsars, from which the sun’s position in the galaxy could be reconstructed by a distant civilization using elementary geometry.

This plaque may be worthless as far as signalling the aliens is concerned, but it speaks volumes about humans. A brief message to an unknown alien community should presumably reflect the things that we consider most significant about ourselves. The picture is dominated by the human shapes, yet our physical form is probably the least significant thing we can say. It is almost completely irrelevant both scientifically and culturally. To put it bluntly, who gives a damn what we look like? The raised hand part is the height of absurdity: such a culturally specific mannerism would be utterly incomprehensible to another species, especially one that might not have limbs. Showing the provenance of the spacecraft within the solar system is of little relevance. If the sun’s location is established, it wouldn’t take a genius to figure out which planet had intelligent life. The plaque also conveys the information that humans are carbon-based. But we hardly need to teach ET chemistry and biology. Carbon is probably the only life-giving element, but if the aliens really wanted to know, they could scour the spacecraft for remnants of terrestrial microbes. Thirdly, and more seriously, a preoccupation with what we are made of is almost as parochial as concern over our physical form. Surely the essence of humanity is what we do and think, not the chemical make-up of our bodies.

This half-hearted attempt to put our stamp on the cosmic community is distinctive in its narrow-mindedness and preoccupation with twentieth-century science and human affairs. In fact, it addresses the sort of topics that appear on the agenda of SETI conferences, but are exceedingly unlikely to be on the agendas of conferences in a 10-million-year-old alien civilization, especially one in which machines or computers are doing the intellectual heavy lifting. As calling cards they are effectively useless.

Well, can I come up with anything better? I hope so. One way to approach the topic is to imagine that our species is about to be annihilated, and we wish to leave a record of our erstwhile existence, perhaps for a future intelligent species that may evolve on Earth in the fullness of time. What would we want to say about ourselves? What do we most value? Which products of our culture are quintessentially human? We might take great pride in our technological accomplishments, such as the Moon landings, or particle accelerators, or genome sequencing; but then again, maybe not. My grandmother’s response to the Apollo programme was ‘Why do they want to go to the Moon?’ She couldn’t see the point. In the grand cosmic scheme of things, technological products may cut little ice, especially among a species that has no left-brain/right-brain dichotomy, no art-science schism.

When it comes to cultural achievements, we are in even murkier waters. Religion I have already dealt with: most religions are highly geocentric and anthropocentric (even ethnocentric), deeply rooted in evolutionary psychology and recent human history. They would be totally meaningless to an alien mind. Great works of literature or poetry are equally parochial, because they celebrate and analyse the realm of human affairs and relationships. Art may have more widespread appeal, although beauty is very much in the eye of the beholder. It is not incon- ceivable that there are universal aesthetic principles, having to do with symmetry for example. Even an alien mind may recognize certain forms of visual art to be making a statement to which it could relate in a general sort of way. But there is no accepted theory of art that isn’t intimately tied to the human cognitive system. The same goes for music and humour: they work well for humans because we share most of our neural architecture. An alien brain will be wired differently, so aliens will find different things pleasing, things that are probably incomprehensible to us. I have left out sport, economics and stamp-collecting for reasons that hardly need to be spelled out.

In the trade-off between content and comprehensibility, we would be wise to err on the side of the latter. There is little point in sending obscure philosophical thoughts about emergence, post-modernism or moral relativism without a library of definitions and background information. Even biology is problematic: apart from the principle of Darwinian evolution, we don’t really know any universal biological laws, so communicating details of protein assembly or gene networks might be of little value. (That may change as our understanding of bio-systems improves.)

Which leaves us with mathematics and physics. The deepest products of the human mind are arguably the mathematical theorems that have been constructed by some of the world’s most brilliant thinkers. Godel’s incompleteness theorem, for example, is so profound that it is possible that no theorem in the universe can trump it. (I make this bold claim because Godel’s theorem is a very general statement about what cannot be known or proved---ever, in principle---rather than about something specific which is known. Mathematics occupies an unusual place in our culture in that it is a product of the human mind, and yet it transcends the mind. Any sufficiently advanced being elsewhere in the universe could prove the same theorems based on the same logical principles. Given that the universal laws of physics are manifested in the form of elegant mathematical regularities, it is clear that mathematics is the key to bridging the gulf between human and alien cultures. If aliens know any science, or have developed any advanced technology at all, then they will be familiar with mathematics. They will even be familiar with the same mathematics as we know. To take an example, Maxwell’s laws of electromagnetism are observed to apply everywhere in the universe, so if the aliens understand the principles of radio---which we are assuming is a prerequisite for radio contact at least---then they will know Maxwell’s equations. What else? Einstein’s general theory of relativity has been described as the pinnacle of human intellectual achievement---it is certainly an impressive accomplishment. Then there is the quantum theory of fields and other esoteric products of theoretical physics that accord well with experiment. If the aliens have gone beyond radio, they will presumably know where the general theory of relativity and quantum field theory fit into the sum total of knowledge about the universe. If we inform them that we have attained that degree of understanding, it will be a benchmark of sorts for them to judge our level of advancement.

The reader might be thinking, Well, he would say that, wouldn’t he? It’s just what you’d expect from a theoretical physicist. Davies is as parochial as the rest of us. But let me defend my choice. Part of the reason I became a theoretical physicist is precisely because mathematics and physics have universal significance. I was attracted to these subjects because they do seem to transcend human affairs, to put us in touch with the deepest workings of nature. If, wearing my hat as Chair of the SETI Post-Detection Taskgroup, I get to reply to ET, I will choose Maxwell’s equations, the field equations of general relativity, Dirac’s equation of relativistic quantum mechanics and a selection of mathematical theorems. It would be like saying, Hey, this is what we can do so far? And ET would know where we have reached in the long quest to unravel the secrets of nature. If ever we got into a protracted dialogue and found ourselves on the same intellectual wavelength, well, then humans could follow up with cathedrals and Picassos and Beethoven symphonies, in the spirit of 'This is what we like. How about you?'

WHY DO SETI?

At its fiftieth anniversary, SETI remains a grand, uplifting enterprise. Its astronomers are as dedicated and positive as ever. The eerie silence has not blunted their zeal or subdued their motivation, for there is always a chance that the next observing run will finally detect something truly convincing. Meanwhile, the routine data analysis and equipment development goes on. SETI is one of very few human enterprises that really does take a long-term view.

In this book I have attempted to explain what we are up against when we embark on SETI, and to critically examine the hidden assumptions that underlie the present strategy. I have argued that the time has come to think much more creatively and to widen the search in novel ways, without compromising the traditional SETI programme. But even the most ardent optimist will concede that SETI is an extraordinarily long shot. All we have to go on are general scientific principles and philosophical analysis. The best that can be said is that no totally convincing argument has been given for why alien civilizations cannot exist.

So why do we do it? Can SETI be justified, given the poor prospects of success? I believe it can, for several reasons. First, it forces us to confront those great questions of existence that we should be thinking about anyway. What is life? What is intelligence? What is the destiny of mankind? As Mr. Drake has remarked, SETI is in many ways a search for ourselves---who we are and where we fit into the universe. When we think about advanced alien civilizations, we are also glimpsing the future of mankind. The eerie silence gives us pause that such a future is by no means assured.

Fifty years is a useful benchmark, and an excellent time to evaluate the programme. It is certainly too soon to get discouraged and wind it up. As I have explained, SETI has sampled only a tiny fraction of potential habitats. But it is equally clear that the galaxy isn’t obviously a hive of alien activity. 'Year after year, deep sky radio searches came up with nothing,' comments David Brin, 'none of the expected “tutorial beacons”. No sign of busy interstellar communications networks. Indeed, no trace of technological civilization out there, at all'. So how long should we keep at it? Because SETI’s version of Moore’s law implies that the search efficiency shoots up exponentially, a hundred years of silence would be very different from twice fifty years. Every additional year that produces a negative result greatly amplifies the significance of the silence, and bolsters the tentative conclusions we may draw from it.

The search for alien intelligence is an exercise in the Copernican principle which, loosely stated, says that our location in space isn’t special or privileged in any way, so that what happens in our part of the universe should happen elsewhere too. The Copernican principle is not a law of nature, only a rule of thumb (‘Why do we think we are so special?’). It inevitably fails at some stage, and the point at which that failure occurs is of enormous importance and interest. The Copernican principle applies well to galaxies like the Milky Way, to sun-like stars within the galaxy, and---so we have recently discovered---to entire planetary systems too. What is not yet clear is whether the principle works or fails for specifically Earth-like planets across the galaxy. At the present time, scientists seem to be about equally divided between ‘rare Earth’ and ‘common Earth’ advocates, but that uncertainty may soon be rectified when the results of the Kepler planet-hunting mission become available. By contrast, we now know that within the solar system Earth is in fact rather atypical in its physical conditions, and that Renaissance scientists such as Huygens and Kepler were wrong to treat our sister planets as on a par with it. When it comes to biology, the case for and against the Copernican principle is finely balanced at this time. It would, however, be immediately resolved in favour of ‘for’ if we discover a shadow biosphere or an independent genesis of life on Mars. That doesn’t take us as far as intelligence or technology though. It is possible that the Copernican principle applies all the way up to complex life, but fails when it comes to technological communities like ours. We may yet be unique.

Of course, we cannot prove a negative. We could conduct SETI for a million years without encountering any evidence of intelligent aliens, but that would not rule them out of existence. There could be all sorts of exceptional reasons why the search missed them. Nevertheless, if exhaustive searches yield nothing---if the eerie silence becomes deafening---then most people would probably think it safe to assume that we are, after all, totally alone. What then?

Concluding that we are unique in the universe would greatly amplify the value we attach to life and mind, and to the planet that sustains them. So the eerie silence could be golden. It’s true that in some sense life---at least intelligent life---would have to be regarded as a freak. But does improbability diminish worth or enhance it? Certainly we should want to take better care of our planet. And we would need to take better care of ourselves too. It would be a tragedy of literally cosmic proportions if we succeeded in annihilating the one truly intelligent species in the entire universe. There is, however, a crucial caveat on which any broad conclusion about the implications for humanity hinges. In Chapter 4, I discussed whether the Great Filter lies behind us or ahead of us in time. If Earth is not just the only planet with intelligent life, but also the only planet with amy sort of life, we will have passed through the filter already, and could be poised for a unique cosmological experiment. We might make it our mission and our destiny to spread beyond Earth, carrying the flame of life, intelligence and culture with us, to bestow this gift on countless sterile worlds. But if we discover that, although intelligence is confined to Earth, complex life is widespread, then the consequences are profoundly alarming and depressing. It implies a much higher chance that intelligence has evolved on many planets in our galaxy and others, but that it always got snuffed out, by warfare, technological accidents or any of a thousand other causes. Unless we had very good reasons for thinking we are highly atypical, then a similar fate would await us.

So the bottom line is simple. There are three possibilities, each with dramatically different implications for humanity. The first is a universe full of intelligence. That is not only exhilarating, but would promise a bright future for mankind. The second is that Earth is a unique oasis of life. That would place an awesome burden of responsibility on our shoulders, yet it would provide us with the truly cosmological mission of perpetuating a precious phenomenon---the flame of reason. But the third possibility---a universe with widespread life and nobody left bar us to celebrate it---is one that bodes very badly for our species.

MIGHT WE BE ALONE AFTER ALL? THE THREE-HATS ANSWER

People inevitably ask me, bluntly, ‘Do you believe we are alone in the universe, or are there other intelligent beings out there somewhere?’ In this book, I have tried to present various for-and-against arguments, but the time has come for me to get off the fence. I can do this only by wearing three hats in succession. First I shall wear my scientist hat. Do I, Paul ‘The Scientist’ Davies, think we are alone? As a scientist, my mind is open to new evidence and therefore not yet made up. I can assign some sort of probability for aliens to exist, based on sifting all the facts, weighted in turn by the relative importance I attach to the various arguments. When all that is put together, my answer is that we are probably the only intelligent beings in the observable universe, and I would not be very surprised if the solar system contains the only life in the observable universe. I arrive at this dismal conclusion because I see so many contingent features involved in the origin and evolution of life, and because I have yet to see a convincing theoretical argument for a universal principle of increasing organized complexity of the sort I touted in the previous chapter.

My answer may be disappointing to the reader. It is certainly disappointing to me, Paul ‘The Philosopher’ Davies. Wearing my second hat, and leaving science to the side, what are my feelings about the nature of a universe in which we are alone? Frankly, it makes me uneasy. I wonder what all that stuff out there is for, when only lowly Homo sapiens get to see it. Of course, my hard-headed colleagues tell me it’s not for anything, it’s just there. The idea that the universe has a purpose, they say, is just a hangover from religion.

Finally, there is Paul Davies, the human being. One of the things that influenced my choice of career was my fascination with the idea that there might be intelligent life out there somewhere. Like all teenagers, I read the flying-saucer stories, and wondered whether there might be something in them. I devoured science fiction by Arthur C. Clarke, Fred Hoyle, Isaac Asimov and John Wyndham, and pictured a galaxy pulsing with alien activity. I watched Stanley Kubrick’s film 2001: A Space Odyssey and rejoiced in the notion that humanity might have an astronomical dimension, soon to be realized. I know other scientists who followed the same path into their careers. My decades of work as a professional scientist have not diluted that wide-eyed schoolboy fascination; I would very much like to believe that the universe is intrinsically friendly to life and to intelligence. It suits my temperament to suppose that our humble efforts on Earth, the daily round that consumes almost all our time and energy, are part of something grander and more meaningful. I can think of no more thrilling a discovery than coming across clear evidence for extraterrestrial intelligence. In romantic moments, I like to think that all intelligent entities, biological or otherwise, enjoy a bond of fellowship that stretches across the vast reaches of space and time, and up and down the IQ ladder. Whether it is godlike quantum minds floating in the black emptiness of intergalactic space, super-cyborgs riding commandeered comets, Matrioshka brains hugging spinning black holes or humble planet-dwelling biological organisms with big brains and fancy technology, I’d like to hear from them. So wearing my ‘dreamer’ hat, yes, I can feel at home in a universe in which intelligent life is commonplace. This is more of a ‘want’ than a ‘belief’, but it is as far as I am prepared to go before Davies the Scientist reins me in.

And that’s what makes SETI so tantalizing. We just don’t know.

THE END