  Chapter 1 Are we alone in the Universe? An interesting title for a lecture, I thought. Professor Theodore Makkinen had just arrived from Princeton to take up the Chair in Theoretical Physics. The public lecture was his first in the new position. Victor had phoned to ask if Elizabeth and I would like to attend, and whether he could save us seats in the lecture theatre. There was bound to be a capacity audience, so I jumped at the offer. It wasn’t every day a Nobel-laureate came to talk at the university, least of all on such a dramatic topic. We’d sit with Victor and Marie. There was no way I could have known that my life was about to change totally. That I would be leaving the job I had known for ten years. The job I was familiar with and which I enjoyed. Had I known, I might well have rejected the opportunity. Why should I pass up a job I liked, working with people I liked, for the unknown? For a job where I felt much less secure, much less certain of my skills and my ability to cope. But I did not know what was to come. The opportunity to attend the lecture I grasped eagerly. With that decision, the future changed. A door opened that ten years before I thought had closed forever. I shook the rain off my umbrella as we entered the Physics Building. The entrance was lit up brightly, contrasting with the gathering gloom of the winter twilight. A weather front was moving up from the south, bringing colder air and showers. I was glad to see Victor waving to us as we entered the main lecture theatre. It held several hundred people and was nearly packed when we arrived, even though we had come half an hour early. I heard somebody say that they had direct video feeds to several other theatres around campus to handle the expected overflow. They were also pumping it live onto the 'Net. We settled down and joined the excited chatter that filled the hall. The audience was diverse. Students with army coats and scarves and long hair. Bow-tie wearing academics. People in suits like me who were administrators of some sort. And just about every other sort of person you could imagine. Makkinen was attracting a wide audience. He was well known in theoretical physics circles but his wider fame was due to his active role in the recent TV debates on extra terrestrial life, following the Mars Lander evidence. Hearing him talk in the flesh was not to be missed. The audience hushed as the Vice-Chancellor walked into the theatre. She was followed by Makkinen. I recognised his burly figure from the TV debates and the many press pictures. A few flashguns went off at the front. There would be more pictures of him in tomorrow’s papers. Our new professor was a much higher profile figure than usual for a theoretical physicist. And he was by all accounts an articulate speaker. After the usual introduction and limelight stealing and expectant applause, Makkinen took the podium. The theatre lights dimmed and the lectern light glinted from his glasses. He had a commanding presence. He went straight to the subject, speaking with a sonorous baritone voice. "Are we alone on the Universe? Until Copernicus, the answer was a resounding "yes". We were the Chosen of God. Since then, in the age of science, the "no" answer has been growing in popularity. Then a year or two ago, it moved back towards "yes". Tonight I want to push it back again in the other direction. To borrow the slogan of that popular TV series last decade, we are not alone. "The Judaeo-Christian ethic teaches that we are the children of God. Theologists have always taken this to mean we are the only children, and that all the bounties of the Earth are at our command. Along the way we picked up certain Aristotelian doctrines that said the Earth was the centre of the Universe. By implication, we were it. "Then about four hundred years ago, along came Copernicus. He rather upset the authorities. The Copernican Principle says that we are not the centre of the Universe. Copernicus, you will recall, put the sun at the centre and the Earth as a planet. This dethroned man’s belief that the Earth was the centre of everything. That came as a rude shock. "The Principle has been extended to suggest that we circle on a small planet around an average star, one among many billions, two thirds the way to the edge of a rather large galaxy, among billions of other galaxies. As a principle it now states that there is nothing special about where we are or who we are. This is now well accepted in scientific circles. Its logical conclusion is that we are by no means unique in the Universe. "The Mars Lander findings and the earlier meteorite studies strongly indicate that Mars once hosted life, and that it evolved quite independently from here on Earth. The latest evidence suggests it still survives on Mars. Preliminary findings from Titan suggest the same may be true there too. This means the Universe is probably seething with life. "But what about intelligence? If you take Copernicus and throw in some probability calculations, it seems likely the Universe is teaming with intelligent life too. Considering the Universe has been around for over ten billion years, some of the civilisations arising are likely to be much more advanced than us. I don’t know about you, but it strains my credulity to believe that we’re the first beings anywhere to exhibit self-aware intelligence. "This raises an important question. If we are not alone, and we are not the first intelligent life form in our region of the universe, we have a problem. A big one. Simple calculations show that it would take us a matter of a few million years to colonise our own galaxy, with technology only a little more advanced than we already have. "We don’t need Warp Drive or any other yet-to-be-discovered physics to get there. Simple present day physics can do it. Maybe our economic base can’t yet sustain the technological effort needed, but that’s just a matter of time. A few generations at most. "The question is this: if we can do it, why not other life forms? Obviously they can. "So where are they? There is still no evidence of intelligent life other than us. Why not? Was Copernicus wrong? Are we in fact alone? "Some argue there is a healthy network of intelligent life through the galaxy, and that it operates a form of Star Trek’s Prime Directive of non-interference. Elizabeth nudged me. "What’s the Prime Directive?" "It’s a principle that says you shouldn’t interfere in any way with a civilisation that hasn’t yet developed interstellar travel." "Oh." Makkinen continued. "Others argue that inevitably there would be some life forms that would ignore this directive. So they should be here by now. "Frank Tippler argues that intelligent life is very rare indeed and that we may even be the only form of it in the Universe. He believes that we are alone. "This raises another question, one that has not been asked to date. It’s one that has been bothering me lately." He paused. "How sure are we that there is no evidence of intelligent life? I mean, evidence here around us. "There are plenty of credulists who say we have been visited by aliens in flying saucers. Horse pucky, I say." The audience laughed. The credulists remained silent, but only for a second. A tall figure stood up towards the front of the audience. He had long white hair and a flowing white beard. Apart from his blue jeans, he could have been cast as Moses. He called out his disagreement. "What about the evidence the US Government is covering up? What about all the alien artefacts they’ve got that they won’t tell us about? You can’t ignore that." Makkinen looked up at him, took his glasses off and replied after a few seconds' pause. "My friend, I’m ignoring nothing. I can’t claim to have examined all the multitudes of stories on cover ups, but I have a few friends in high positions in the US Government, and I’m completely satisfied that there is no evidence of dead aliens or their craft. I’m aware of no cover up conspiracy. None. Period. "But don’t get me wrong. That doesn’t mean I’m arguing against the existence of aliens. I just think we’re being too simple minded in thinking in terms of flying saucers. Bear with me and judge what I’m saying when I’ve made the full case. He replaced his glasses and looked down at his notes. "Realistically, there is no evidence of aliens that we have been able to detect with our technology. No crashed starships, no faint signals from the stars. This can mean one of three things:
"The first option is barren and depressing, though it has been argued cogently by Tippler and many others. The arguments are complex, but in the end you have to make up your own mind. Personally, I just think it's wrong. I can provide no evidence yet to prove this. At least, not yet. "The second option is perhaps plausible. Twenty years ago we thought the 21 centimetre hydrogen line was the most likely frequency to choose for interstellar communication, as it was easy to identify for anybody. Quite why this was suggested was never clear, as it is the one frequency most likely to suffer interference and absorption by natural sources. Another nudge from Elizabeth. "21 centimetre hydrogen line?" "That’s the wavelength of the radio waves emitted by neutral hydrogen molecules in interstellar gas clouds. You can detect these gas clouds using radio telescopes. It’s a sort of universal background hissing." "Oh." "These days, the technology used by the people at SETI is capable of scanning huge frequency ranges. The technology that we use to try to detect alien communications has changed enormously even in twenty years. We don’t need to try and work out a single radio frequency that aliens might be using to say hello. We can scan the lot. "So why shouldn’t we expect similar changes in technology to continue? One answer is, at least with our current understanding on how to generate energy, that no form of communication that is feasible is unknown to us. "I'll put that another way: we know all the ways aliens could use to communicate. Anyone even remotely like us out there is constrained by physics to use communication media that we know about. We believe that we do know all the likely channels. "There are a few question marks still, but not big ones. One is about civilisations and the amount of energy they can harness to accomplish their shared goals. There’s also the question of neutrino modulation." He paused. "But that’s way beyond what I want to talk about tonight. "The last of the three options is perhaps the most interesting. To my knowledge, no-one has yet addressed it. It is this: are they here already, and we just haven’t noticed? Everybody assumes the answer to this is "no". I mean, if they were here, wouldn't we notice? I think we should explore the question more thoroughly. That's what I want to do for the rest of this talk tonight. "There are a few observations that I want to make, to start with. "We are driven, because of our own finite life span, to communicate and understand information as fast as possible. We haven’t thought about what imperatives might apply for life forms that have transcended the life span barrier. Perhaps they would feel no need to communicate at the rates we use. If their communication rates are slower than a few bits per hour, it is unlikely that we would notice their communications. They could use signal carriers so close to DC that we would not even look for them as carriers. Another nudge. "Carriers?" "They’re varying signals - like radio waves - that you generate and put your communications information on top of, to transmit them through space." "Oh." "We also make assumptions about intelligence that are remarkably Homocentric. We see ant colonies and recognise the similarities to our own societies. We also see vast differences in consciousness between the ants and us. Yet we tacitly assume that life forms more advanced than our own have developed no substantially higher form of consciousness. We always think in terms of "little green men" operating vehicles something like our own. I think this is pretty naïve of us. "If this is wrong, and advanced life forms have developed a higher consciousness than us, we can only speculate what insights this might provide. We have to ask ourselves how we might become aware of this higher intelligence. It certainly won't be flying around the place in UFOs! "If, for example, by linking together millions of individual human minds in a giant neural network, we were to induce some sort of higher conscious group-being, it is unlikely that individual minds themselves could comprehend the higher thoughts of this higher consciousness, any more than a cell in our own brain is aware of the thoughts of the entire brain. "Let me take this further. It is very unlikely that a single cell in my brain is aware of what you are thinking. So is it reasonable to suggest that we as individual humans should be able to understand the thoughts of alien higher consciousnesses? I have my doubts. I think the best we can do is to identify their communications activities. "What I’m getting at is that we shouldn’t expect alien visitors to leave behind the sort of rubbish we might. Archaeology is based on the fact that humans leave behind their artefacts. Consider what we’ve already abandoned on the Moon, Mars , Venus and recently, Titan. For some reason we expect the aliens to do the same. "We assume there is no evidence of alien life forms having visited our planet just because there is no artefact-based evidence for this." He paused and smiled across at his recent interrupter. "And please don’t mention Mr von Daniken." "No. A lack of alien artefacts does not imply a lack of aliens. Assuming that they leave artefacts behind is dangerous. It is an assumption we must not make. To explore the implications of not making it, let me ask a few more questions. "What form would a higher alien intelligence take, if it were present here? "How would we recognise it? Presumably through its communications? "What form of communication would it use? We assume that it would communicate with like forms elsewhere, as communication is a sign of intelligence. In our experience, the higher the intelligence, the more sophisticated the communication. "Can we ever be aware of the intelligence, other than to know that it somehow exists and is communicating? "Is humankind as a species likely to become such a higher intelligence? "Will we know if we have? "And I might as well throw in the hoary old one, how far are these questions from asking whether we can know God? "Though it may disappoint you, I won’t be answering most of these questions tonight, just a few to whet your appetite. The audience started to murmur as Makkinen asked these questions. It was obvious people were taking the ideas seriously. The Vice Chancellor rapped on the table in front of her to subdue the activity. Makkinen continued when things had quietened down a little. "As to the form that a higher intelligence would take, I argue that it would be a neural network. That is, individual active entities that can intercommunicate, and together make up the larger organism. If such an organism exists here on Earth, we are not yet aware of it. "But what if it does? Can any likely candidates be put forward? I believe so. The audience was completely silent, waiting on Makkinen's next words. He paused for dramatic effect. "If, as some hypothesise, telepathic communication exists between animals, then a neural network of telepathically communicating species could provide such an organism. How one could detect their communications must remain unanswered. The hypothesis demands a leap of faith, given the current scientific doubt about the existence of telepathy. He paused again. "Another possibility is trees." A few people in the audience laughed nervously. "There are countless millions of trees on this planet. They generate electromagnetic fields that could be modulated to intercommunicate. This does not need the leap of faith that telepathy requires. And the best thing is, we can test the hypothesis. We merely need to look for low frequency modulation of the electromagnetic fields around trees and the currents they induce in the surrounding soil and air. "We must also find a correlation between the field modulations for different individual entities. That would indicate an exchange of information. If such communication between the neural net entities can be detected, then we can take matters further to explore interstellar communication. If you’ll pardon a poor tree joke, I think SETI may be barking up the wrong one. We don’t need to look for interstellar aliens as a first step. The evidence for alien intelligence may be outside our own front doors. The audience started to murmur again. This was pretty extreme stuff. Was he serious? "I detect that I’ve got a reaction from some of you. That’s good. No reaction means no communication, either that or I’m preaching to converted minds. Which is not something I’m prepared to accept. "Remember this talk is a provocation. To make you deal with the unacceptable. But I digress. Let me explore the ideas further. "Trees have been around for perhaps 300 million years, since the Carboniferous Era. That’s plenty of time for them to have been colonised by an alien intelligence. I’m not suggesting that trees are the actual aliens. Far from it. They have evolved from the first single cell organisms on Earth over 3 billion years ago, just like us. Genetically they're closely related to us. No, what I’m suggesting is that they may act as the conduit for an alien higher life form, taken in totality, not tree by tree. Think about that for a minute. He paused and took a sip of water from the glass on the lectern. A muted buzz spread through the audience. Makkinen looked out at the audience for a few seconds. Silence took hold again. "What I'm suggesting, and not in jest, is that the planet's tree population might form the basis of a neural network that could host a higher intelligence. All we need to do to confirm this is to detect correlated signals between the neural entities - that is, the individual trees - and then find evidence for this global entity transmitting some form of global signal to other places in the universe. "Let me back up my assertion with a few statistics. The human brain consists of perhaps a billion neurons, each of which can commuicate electrically with anywhwere between ten and a thousand of the other neurons. Interestingly, and depending on how your define the term "tree", there are perhaps ten billion trees on the planet. In theory, this could form a brain many times as powerful as a human brain, if each tree could communicate with many of its regional neighbours. "In fact, with sufficiently low frequency communicaton, all the trees in the world might be in reach of the hypothetical transmissions of a single tree. You will recall, I think, that the US Government still has a very low frequency radio transmission capability on your own Northwest Cape, to communicate globally with its nuclear submarine fleet. So the physics of surface guided electromagnetic waves provides a natural communicaions medium, ready-made. "You might argue that a single tree might not be able to generate a signal that could be heard above the normal atmospheric electrical noise. Very likely true, but what's to stop groups of trees singing in chorus? "You will also ask, of course, how could these innocent trees, quietly minding their own business and evolving for millions of years, suddenly become the host for an alien intelligence? Of course, I don't have the answers. But consider for a moment that all life on earth seems to be coded in the DNA sequnces of genes, which is, fundamentally, using four amino acids connected in complicated ways to store stupendous amounts of information. Why then could we not suppose that there is some way of remotely imposing information, transmitted at the speed of light, onto a susceptible host population, in a way that would make it self-organising? That seems a perfectly reasonable, if wild, speculation. Makkinen paused for another sip of water. The auditorium was quiet. "Now I'll admit this is all very much in the realm of high speculation. If I wrote this sort of stuff in my theoretical physics papers, the Nobel Committee would strip me of my recent award. The audience laughed and the tension broke. Makkinen beamed out at the darkened auditorium and continued. "But this is not theoretical physics, just a fun diversion. So let us entertain the ideas without judgement for a little longer. "If these ideas have any basis in truth, what do they imply? Before we go out and set up thousands of dollars' worth of equipment in the nearest forest, let us ask what sort of correlates we might already be aware of. "Most of us here are worried about the denudation of the world’s forests. If the trees are the basis of an alien neural network, surely it’s aware of what is going on? Possibly. Remember, a neural network with sufficiently many elements is very stable against the loss of some of them. The odd tree getting killed by lightning or disease will have no effect at all on the network. New ones can be absorbed into the network as they grow. Even the Borneo-Sumatra catastrophe of a few years ago might have little effect except in the very short term. But if enough of the elements of the neural network that forms the higher intelligence are removed, the overall performance of the network will suffer. Sort of like getting Altzheimer's disease. We might expect there to be some response to the loss of perhaps 25% of the elements. We’re approaching that point now with deforestation. "So is there any evidence of the trees taking revenge? Nothing obvious. At least, I’m not expecting Birnam Wood to approach Dunsinane tonight. A titter spread through the audience, then a murmur. I nudged Elizabeth. "Birnam Wood?" "MacBeth." "Oh." The murmur subsided. There were obviously others besides me in the audience who were not up on their Shakespeare. "But this isn’t a silly question if my hypothesis is sound. Will the neural net not defend itself against such attacks? We might ask, how would it protect itself against our depredations? Would its response be violent or subtle? Perhaps so subtle as to be undetectable? I don’t know, but I rather think it would be subtle. In which case the lack of a vigorous response to date doesn’t rule out my hypothesis. "Of course, this is well into the realm of speculation, and I’ll speculate a bit further. Maybe there already is an influence affecting us as a result of the deforestation. I ask you to ponder the rise of the Green movement. It’s not by chance that it coincides with deforestation. The devastation offends civilised minds and there are obvious climate change concerns to explain it. But is there some deeper force orchestrating it? I don’t know. But it’s worth thinking about. "Another speculation you might entertain is in the arena of traditional beliefs. For example, the veneration of trees by the Druids. Tree worship is possibly the oldest form of religion. It turns up in many different cultures. Who knows? Maybe they knew something? Makkinen closed his notes folder, took off his glasses and paused as he looked out at the audience. "To close, I’d like to provoke you once more. I don’t expect for a second that you’re going to take my trees hypothesis seriously. At least, not at first. But when you walk out of here tonight, as you commute back to your homes, take a look at the trees you pass, and ask yourself, are they just plants, or are they the focus for an alien life form? I guarantee, you’ll never look at trees quite the same way again, if this idea gets under your skin. Thank you." The audience was silent for a second. Then the applause started - polite for a few seconds as people reacted to the ideas they had just been handed - then it grew to genuine warmth. Whatever the new professor was, he was not your standard academic. The usual questions session followed. A blizzard of questions. Most focussed on the recent evidence from the Mars Landers. "Yes", Makkinen said, "the evidence suggests there is still primitive microbe life on Mars. It seems to look a lot like the initial images from the Martian meteorites a few years back. There is evidence of metabolic activity in the samples analysed. That means life, we think. But we won’t be certain until we can bring back samples and analyse them in the lab here on Earth. And that’s a few years away. If it is verified, it means primitive life arose on two neighbouring planets independently. That’s amazing. It means the Universe must be teeming with life. And I think some of those life forms just have to have achieved self consciousness." Then someone raised a different question. A tall young man with gaunt features and a goatee beard. He looked about twenty three. He might have been a graduate student. "Professor, you mentioned neutrinos. Wouldn’t using neutrinos be one way to communicate? How would you impose a signal on a neutrino beam?" "Yes. Neutrinos... Makkinen looked out at the wider audience, pausing. "For those of you who’ve not yet come across them, neutronos are fundamental sub-atomic particles: they’ve been described as the nearest thing you can have to nothing, without actually having nothing. They are generated in nuclear reactions in the cores of stars. They interact with practically nothing. A million miles’ thickness of lead doesn’t stop them. There are billions of them travelling through you every second, some of them left over from the Big Bang itself. But don’t worry, they won’t hurt you. "There are two problems with using neutrinos to communicate. The first is generating them. You need nuclear reactions to create them. So you need some sort of nuclear reactor -- an atomic pile, a high energy accelerator or a fusion reactor. Or, ideally, a handy star. But a much bigger problem is focussing them. It’s so hard to affect them that you’d need something the size of a small planet to create a modulated beam of them. I think that if aliens were focussing beams of neutrinos, we’d know about it!" He smiled. The questioning resumed on life on Mars. .................. Finally the presentation ended. Numbers of students clustered around Makkinen near the podium, seeking his autograph on books and other items. More camera flashes illuminated the arena. We trooped slowly out of the theatre amid the crowds and the quiet hum of conversation. People would talk about this for quite a while. Elizabeth and I said goodnight to Victor and Marie and headed for the car. We walked along the roadway from the physics theatre to the car park some hundreds of metres across campus. We said nothing, absorbed in thought about what we had just heard. The streetlights reflected off the wet roadway. It was covered in puddles. The rain that had been starting when we arrived had come and gone. The clouds were beginning to part. The night sky beyond them was dark and very clear. I could see the star-clouds of Sagittarius glowing. We reached the car, parked under a giant gum tree. The tree must have been at least two hundred years old. I looked up at the Milky Way through its branches. "Do you suppose it’s communicating with anyone out there?" Elizabeth asked. We stood for a minute looking up at the branches silhouetted against the night sky. David Nicholls This is the first chapter of an emerging book, "Tree Song". If you like it, . Better still, let the book publishers know, and tell them where to find this chapter! |