The Science of Avatar

²⁴ HUNTERS OF THE FOREST

In the movie Avatar the Na’vi we learn most about are Neytiri’s Omaticaya clan. There are however many other clans on Pandora, which we glimpse when Jake as Toruk Macto calls on the Na’vi to unite against RDA. Na’vi languages differ to a minor extent, as do their physiologies—details of their height, their skin tone—but they all seem to be of one species, as the many races of mankind are a single species.

The Na’vi live essentially by hunting and gathering, from the natural fruits of the world around them. Hunter-gatherers typically live off a variety of food sources. They really do hunt and gather. Among humans, hunting may be a prestigious male activity, though the women’s gathering of food from sources like roots, fruit, nuts and small animals may actually bring in more nutrition to the group. But it’s wrong to over-generalise and to draw gender stereotypes; every culture is different. Certainly the variety of food we see in Avatar is credible, from avatar-Jake’s first mouthful of fruit when he escapes from the lab, to the teylu larvae he eats during his first encounter with the Na’vi, to the hexapede he hunts down with Neytiri. The Na’vi do however have a kind of incipient agriculture, which they call ska’waylu which means encouragement, a kind of elementary husbandry of favoured plants. This behaviour is thought to have led to the development of full-blown farming on Earth.

Thus the Na’vi. Once, all humans lived as the Na’vi do.

In the long ages before the coming of farming—in Eurasia the period is known as the “Mesolithic,” the Middle Stone Age—everybody on Earth lived as a hunter-gatherer. The makers of Avatar based aspects of their depiction of the Na’vi lifestyle on the lives of hunter-gatherer forest dwellers in South America and Africa.

But surviving hunter-gatherer communities have been pushed to the margins by the spread of farming in prehistoric times, and by empires and colonies later. Today they are only allowed to subsist on land the farmers, loggers and miners can’t use, or haven’t got to yet. Modern examples probably don’t give us an accurate picture of how hunter-gatherers might have lived in the past, on the richest grounds, and before their ecologies and lifestyles were reshaped by contact with the farmers.

In particular, the Omaticaya clan in their Hometree are sedentary; they are based in one place all year round. We think of hunter-gatherers as mobile—nomadic, moving with the herds and the seasons. But there is plenty of evidence from the past that where resources are rich enough hunters would choose to be sedentary, like the Omaticaya. The North American Indians of the Pacific Northwest are an example. Modern hunter-gatherers generally don’t have concepts of “ownership” of the land. Either they are on the move in search of resources, or they live in a land so rich there’s no need for conflict over ownership; there’s enough for everybody. But perhaps the sedentary hunter-gatherers of the past were territorial, as the Omaticaya are, and would have rallied to Jake’s battle-cry of defiance against RDA: “This is our land!”

Similarly, modern hunter-gatherer groups typically don’t have hereditary leaderships or rigid social hierarchies, and here again the Omaticaya, led by a named individual in clan leader Eytukan with a named heir in Tsu’tey, seem to be atypical. More usually “leaders” would be selected on the basis of skill or prestige for specific purposes, such as leading a hunt—rather as when Jake as Toruk Macto, “rider of the last shadow,” assumes the mantle of leader specifically for the fight against the SecOps forces. But again, we do know that stratified social hierarchies could arise among the sedentary hunter-gatherers of the past, and maybe in the Na’vi in that respect too are true to the past on Earth.

What about war? There’s clearly evidence of warfare among the Na’vi. The young male Tsu’tey defines himself as a warrior, and the clans come together willingly to face the external threat of SecOps. Large-scale warfare is thought to have been rare among hunter-gatherers because population densities were too low to support large armies; conflict was smaller-scale, ritualistic.

Among the Na’vi, the Earth explorers learn that warfare is rare unless brought about by external stresses—population displacements because of some natural disaster like a volcano, perhaps. Fighting tends to be fierce but brief, followed by intense efforts to resolve the conflict. Na’vi wars don’t lead to the elimination of whole peoples, as ours do. However, the Na’vi’s past must contain many stories we haven’t yet been told.

As with the Na’vi, human hunter-gatherers generally don’t see themselves as separate from the natural world which sustains them. The Na’vi even sleep cradled by nature. In the womb of their Hometree, the Omaticaya sleep in “hammocks” that are actually living plants. And the Na’vi know their world intimately, as we see onscreen when Neytiri hunts with Jake. In pursuit of their prey Neytiri is able to detect the subtlest clues: trails, tracks near the waterholes, the smallest scents and sounds.

Hunters rely entirely on the bounty of nature to sustain them, and they know it. They are bound into natural cycles of life and death. They will often pay their respects to the animals they have to hunt for meat, just as we see among the Na’vi when Jake, completing his initiation hunt, brings down a hexapede in a “clean kill,” and thanks it for the gift of its body to the people, while its spirit goes with the Great Mother Eywa. This applies to the life and death of people too. The Na’vi believe that spirits are endlessly recycled through Eywa; nothing is lost—and for the Na’vi, this is literally true (see Chapter 29 on Eywa).

Hunters’ mythologies, whose purpose is to establish relationships between humans, nature and the gods, reflect this perception of unity. Hunters may see spirits in the animals and plants, and in the physical structure of the world, in rocks and sky and rain. Myths of creation and the nature of the world are diverse. In North America, however, some types of creation myths are common, with a “Great Spirit” lying behind all creation, like the Gitchi Manitou of the Algonquians, though more definite and active figures are often imagined, like the widespread Mother Earth and Father Sky.

So Eywa the Great Mother is not an uncommon archetype, although, as Grace Augustine learns, Eywa actually has a biological basis. Otherwise Na’vi religion contains elements of many forms of religion on Earth, from monotheism, worship of one true god, to animism, the idea that the gods are immanent in every aspect of the world.

Mo’at, mother of Neytiri, wife of Eytukan, clan matriarch, is tsahik—“like a shaman,” Grace Augustine says. A shaman is a pivotal figure spiritually, able to mediate between the spirit world and the human world, perhaps through trances, dream states or narcotics. This is the role we see Mo’at play in the scenes in the Tree of Souls as she tries to shepherd the spirits of Grace and Jake out of their bodies. In Mo’at’s case there is a physical, observable link between herself and Eywa, but her shamanism is a reflection of widespread religious practices on Earth.

Among the Na’vi, as among similar human groups, there is no clear distinction between religious practices and those of everyday life; they don’t save it all up for Sundays. Initiation rites are common on Earth, doubling as training, testing and indoctrination programmes for the young, and ceremonies to mark the movement from one stage of life to the next—and they are often just as dangerous as those Jake endures to gain acceptance with the Omaticaya, like the Iknimaya, his “stairway to heaven” climb in pursuit of the banshee.

Just as the Na’vi see themselves as bound into nature, so they are bound into their communities. The Na’vi are intensely social. We can see from the evidence of Neytiri’s family that they are monogamous, and that they are close to their children. They eat communally, in one great hall, gathered around a central fire as many human communities would. There doesn’t seem to be much privacy in Hometree, but that’s like dwellings in our own past, even Iron Age roundhouses. And when Jake is accepted into the Omaticaya they touch each other in a web of physical contact that includes the whole clan, and Jake, its newest member. Their wider sociability may be a by-product of their neural linking with each other and with Eywa (see Chapter 29).

Na’vi seem to have few children, compared to most human hunter-gatherer groups which are typically afflicted by high child mortality and a low life expectancy. Perhaps Na’vi children have a better chance in their world than human children do in ours. This would certainly change the demographic mix and the social dynamic of a clan.

So the Na’vi are expert hunters, bound in to nature, intimately social—and, clearly, highly intelligent.

The Na’vi’s intellect is clearly expressed in the art of their artefacts and decorations, such as body paint and clothing. We even glimpse pieces of Na’vi art hanging on the walls of the Hell’s Gate base. The Omaticaya clan particularly pride themselves on their brilliant textiles. Their largest loom, called the mas’kit nivi sa’nok, “mother loom,” has pride of place in Hometree.

They can count. In Dr. Grace Augustine’s images of her time running a school for Na’vi children, we glimpse the Na’vi’s octal arithmetic—that is, a number system using the base eight, derived from their eight fingers, as ours is based on ten.

And the Na’vi know something of their history. Neytiri tells Jake that her “grandfather’s grandfather” became Toruk Macto when the leonopteryx chose him as its rider. This has only happened, says Neytiri, five times since “the time of the First Songs.” Now, her grandfather’s grandfather takes us back four generations, and so “the time of the First Songs,” before all those other Toruk Mactos, must be many generations further back still. The Na’vi don’t have any writing. Is it plausible that a non-literate people could remember events that far back in time?

In fact, on Earth oral traditions can sustain knowledge over many generations. The Trojan War is thought to have happened around 1200 B.C., at the end of the Bronze Age. But Homer, who composed the Odyssey and the Iliad, did not live until around 700 B.C.—twenty generations later, in the Iron Age. Between those dates lay a calamitous interval known as the “Greek Dark Ages,” when the Greeks lost literacy altogether. What seems to have happened is that oral traditions preserved the memory of the Bronze Age wars, in songs and poems, until Homer and his contemporaries and successors wrote down versions of them. Achilles and Hector may not have been real, but scholars today have detected many authentic details of Bronze Age life and warfare in Iron-Age Homer’s words. So non-literate peoples are indeed able to preserve memories across many generations—as long as the story is good enough.

Researchers on Pandora find evidence of a strong oral culture among the Na’vi. Their oral tradition, of songs and story-telling, is thought to go back some eighteen thousand years. Perhaps this is why their basic language is uniform across the planet. Of course the Na’vi have a deep biological connection to that great information store Eywa at their disposal, but personally I like to believe that the Na’vi don’t need Eywa to remember their own heroes.

The music of the Na’vi is another expression of high intellect, and one of the most memorable aspects of the movie. For example, in the scene following the destruction of Hometree and the retreat of the clan to the Tree of Souls, the Omaticaya sing a hymn-like song of loss and imploring, striking and beautiful to our ears. Neytiri associates music with the roots of her culture—“the time of the First Songs”—and the Na’vi appear to use their singing to reinforce their bonds with each other, and with Eywa.

All human cultures seem to make music, though nobody quite knows why, as it’s not as obviously useful as fire-making or cookery. It is used for common purposes, such as in play with infants, and to mark important events like weddings, funerals and religious rites. Musical styles are hugely variant, but it has been shown that listeners can tell whether music from a widely different culture is meant to be happy or sad.

Nobody knows if there are common fundamentals in terms of how we comprehend music. Since the ancient Greek Pythagoras, some theorists have held that notes with simple frequency ratios—like notes an octave apart, made by plucking strings in the ratio of 1:2—are in some sense natural in terms of the evolution of our auditory capabilities, and will appeal to everybody. But there’s much more to music than simple mathematical ratios; even the blues scale features dissonances.

Music is among the most sublime products of our minds. Indeed some have suggested that if we signal to the aliens we should send them, not mathematical codes or history lessons, but Bach fugues. But is it likely that aliens would develop anything like music, or even comprehend ours? Clearly music of our sort works because of the way our bodies and minds process sound. If the Na’vi’s hearing is different from ours (see Chapter 25) then our music would seem distorted to them. And a bat, who “sees” using sound waves, would presumably perceive our music altogether differently—though conceivably an intelligent bat might appreciate its patterns and symmetries, even if it didn’t experience it as we do. Conversely, a species that “heard” electromagnetic radiation rather than acoustic waves could create music that we might see as patterns of light. In the movie Close Encounters of the Third Kind humans try to communicate with the aliens’ mother ship using a simple musical pattern matched by a light display.

You’ll find in sources like Pandorapedia much more detail on how the film makers intricately constructed Na’vi music. The basis is singing and drumming as in many hunter-gatherer cultures, but it incorporates for example tonal and rhythm structures different from what we’re used to in western culture.

It would be fascinating, if we ever do encounter the alien, to learn if something like music really is a universal feature of intelligence—and even more fascinating to hear alien music, the product of minds quite unlike our own. But to the Na’vi, their music is simply a sublime gift of Eywa.

Another interesting aspect of Na’vi culture is their language, often subtitled onscreen. And it’s a “real” language—or at least, it’s a designed one. Paul Frommer, a linguistics professor from the University of Southern California, devised the language for the movie. The new language has its own sounds, syntax and grammar, with elements borrowed from human languages; Frommer coached the actors who would have to speak it.

Constructing languages has a long tradition. You might make up a language in the hope of easing human communication, as a linguistic experiment, or to support the artistic creation of an imagined world, as in the case of Avatar. The earliest non-natural languages were supposed to be supernatural, such as the “Lingua Ignota” of St. Hildegard of Bingen in the twelfth century. The most famous “auxiliary language,” devised for international communication, is Esperanto, introduced in 1887. Some seven hundred such languages have been created worldwide.

It’s a paradox however that even as we are creating new languages we are letting old ones die out. According to the United Nations Permanent Forum on Indigenous Issues, humanity today uses over six thousand languages, of which three-quarters are still spoken by just handfuls of indigenous people—and every two weeks a language goes extinct. If we lose language diversity we will lose key insights into the potential for human thought and expression, and we will lose something of our own past too; history can be traced through language evolution.

In fiction, Burroughs’ A Princess of Mars features Barsoomian words, the first of which John Carter has to learn is “Sak!”—“Jump!” The “Newspeak” of George Orwell’s 1984 was intended as a device to restrict human thought. The most famous science-fictional language to date is surely Klingon from Star Trek. There is now a Klingon Language Institute, and at least one parent is said to have tried to raise his son as a “native” Klingon speaker. There is even a version of Hamlet in Klingon—or rather, as any Trek fan would put it, in the original Klingon.

By comparison the Na’vi tongue is very new, with a still-small vocabulary and rules that are gradually emerging. There is however pressure from a global community of enthusiasts for it to develop further. For one thing, a language expresses the culture that originates it, and Na’vi culture is rather more pleasant than Klingon.

The Na’vi’s culture reflects hunter-gatherer lifestyles once found across planet Earth. And given how long the peoples of the Earth were isolated from each other, in the case of the Australians tens of thousands of years, and yet developed similar life ways, perhaps this is plausible; perhaps we are seeing cultural universals in play.

We have to remember though that by the time Jake visits them, the Omaticaya are already a people transformed, if not traumatised, by their contact with humanity. They have had to coin names for humans and their artefacts: a Scorpion gunship is kunsip. Attempts by RDA to negotiate treaties with the Na’vi have stalled because of fundamental cultural differences; the Na’vi derive all their “rights” from Eywa, who protects all, and so to them there is nothing to negotiate. And the interaction of Na’vi with humans has grown more violent with the years.

Maybe the behaviour of the Omaticaya is already atypical of the Na’vi on the rest of Pandora. In the same way the horseriding culture of the plains Indians of North America, which has provided later generations with a classic image of “unspoilt” pre-contact peoples, was at the time of the Old West only a few hundred years old. Until the European immigrants imported them, there had been no horses in North America since they went extinct many thousands of years earlier.

So the Omaticaya may not be “pure” Na’vi. Still, contact with them shows that they behave like us.

And, not only that, the Na’vi look remarkably like us.

²⁵ OTHER BODIES

Why do the Na’vi have a mere four limbs? Most Pandoran animals have six. And indeed, why only one neural queue rather than two, and only one set of eyes, and no supplementary breathing vents?

Do the Na’vi look more human than they’ve a right to?

In Chapter 23 I noted that the four-limbed body plan that we share with every other vertebrate land animal (not to mention the birds, the flying reptiles of the past and creatures that have returned to the water such as the whales) is a relic of that common wheezing four-limbed fish-grandmother who first hauled herself out of the water many millions of years ago. On Pandora, judging by what we see of the six limbs of animals from the direhorse to the leonopteryx, that ur-mother must surely have been six-legged herself. The Na’vi aren’t unique with their four limbs; the banshee too are quadrupeds, but it’s clearly highly unusual.

There is an onscreen hint of how the Na’vi’s four-limbedness might have come about. The prolemuris, a monkey-like tree-climbing creature, appears to be the closest animal to the Na’vi in form. It too has just one neural whip, no vents, one set of eyes. And its arms are, if not quite like the Na’vi’s, not like the limbs of other creatures either. It has two sets of forearms, but its upper arms appear to have fused, so that the limbs branch from the elbows. Maybe this is a glimpse of the evolutionary trajectory the Na’vi have followed. But we have to remember that the protolemuris is as fully evolved a creature as the Na’vi, and its peculiar fused arms serve a purpose in the particular way it lives its life; its arms help it with mobility as it clambers through the trees. In the same way, while chimps may holds clues as to our own evolutionary history, a living chimp is not an incompletely evolved human—it is a fully evolved chimp.

Our humanoid form converges with the Na’vi’s in a number of other ways, many of them quite subtle. They have reasonably human-looking sets of teeth, for example. Our teeth have evolved in response to the mixed diet we omnivores have to cope with: canines for killing prey and tearing meat, molars for grinding vegetation. The Na’vi evidently have a similarly wide food base. And they needn’t have had teeth at all. Teeth seem to have evolved from the scales of the ancestral fish that crawled out of the sea, but teeth themselves are surely only one engineering solution to the problem of crushing and tearing food prior to digestion.

And the Na’vi have red blood, like ours. You can see this when avatar-Jake punches out warrior Tsu’tey. Why is blood red? The purpose of blood is to deliver essentials such as oxygen and nutrients to the body’s cells, and take away waste. In vertebrates like us, it consists of blood cells suspended in a liquid called blood plasma, which is mostly water with dissolved proteins and other products. The majority of the blood cells in your body are red; the other sort, white blood cells, includes platelets which help your blood to clot. Red blood cells contain haemoglobin, an iron-containing protein. This bonds chemically to oxygen to transport it around the body—and when haemoglobin is oxygenated, the blood is bright red.

As the Na’vi are functioning in an oxygen-rich atmosphere they must need some equivalent of haemoglobin in their blood to transport the oxygen around their bodies, and indeed the active biochemical in their bodies is an iron-based compound like haemoglobin. But it didn’t have to be haemoglobin or anything like it; some molluscs use a molecule called haemocyanin instead.

Of course there are evident differences between Na’vi and human, including the Na’vi’s senses. Na’vi eyes are four times larger than a human’s, and much more sensitive. They can see beyond the human range, into the near infrared. This would be a great help to the Na’vi in their dimly lit bioluminescent forest. A Na’vi’s ears, meanwhile, are mobile, like a cat’s. This would help sense the direction a noise is coming from, another adaptation useful for forest hunters. But Na’vi ears are expressive as well as functional. They move in response to what is said, and emotions expressed. Na’vi ears aren’t just hearingcups; they are part of Na’vi faces.

However the single biggest bodily difference that Jake notices, when he first wakes up in his avatar body, is his tail—and he does a good deal of damage with it before he learns to control it. The Na’vi use their tails for balance and direction changes when running, and to grip tree limbs and vines when climbing.

Why should the Na’vi have tails, and humans not? A tail is certainly useful if you’re planning to live up a tree. All New World monkeys have tails, and in some, like the spider monkeys, it is prehensile, like a Na’vi’s; that is, it can be used like an extra arm. Monkeys can hang from their tails alone, or from any combination of arms, legs and tail.

Our deepest primate ancestors had tails too, but we, and our ape cousins, lost our tails over evolutionary time. Body features which are not used tend to shrink or disappear, even eyes, such as among fish that live in unbroken dark. There are plenty of other creatures who have lost their tails, such as moles, hedgehogs, bears and sloths.

However, the biologists don’t understand quite why we lost our tails. It presumably has something to do with the way we and our cousins have learned to walk on two feet. Monkeys which are very active in tall trees, running along the branches, jumping and swinging, use their tails a lot, including for balance. But creatures that move slowly in the lower branches, like sloths and koalas, are tailless. In Borneo the long-tailed macaque lives high in the trees—and has a long tail, as the name indicates—while its close cousin the pig-tailed macaque lives on the ground, and has a short tail.

With apes, the picture is more complex, and perhaps has something to do with walking on two legs. Chimps after all do climb trees, and so do gibbons, and neither has a tail. But these creatures are often seen to walk bipedally, and perhaps that has led to natural selection against tails. With us the selection pressure must have been more extreme. After our ancestors split from the chimpanzees they became creatures like upright chimps, australopithecines, clinging to the forest edge yet foraging out onto the savannah, gradually becoming more and more committed to bipedalism. Goodbye tail.

As for the Na’vi, their evolutionary trajectory has clearly been different. They have stayed closer to their forest. Compared to us they are terrifically adept in the trees, good at running along narrow branches, at swinging like Tarzan, at leaping huge distances. No wonder they have retained their tails.

Other Na’vi tree-climbing adaptations might include their bone structure, which is strengthened by a natural carbon fibre, an advantage shared by many Pandoran creatures such as the banshee. And perhaps they have better proprioception than we do. Proprioception is the sense of the position of the parts of the body—of place, movement, locomotion. Maybe that’s why the Na’vi, on the backs of their banshees, are such good natural pilots.

We glimpse the Na’vi’s closeness to their trees in one other touching detail. During his first night in Hometree, avatar-Jake sleeps with the Na’vi, curled up in a leaf-hammock high in the branches. In the background we see a family group tucked up in a single leaf-hammock. The leaf-hammock is a plant, an epiphyte, a plant not rooted in the ground but using the tree for support, while extracting nutrients from rainwater and other sources. The Na’vi call the hammock “safe in the arms of Eywa”—Eywa k’sey nivi’bri’sta. Similarly the chimps like to sleep in nests of leaves high above the ground. And, I like to think, maybe our australopithecine ancestors returned to sleep in the green comfort of the high branches, after a day in the brutal openness of the savannah.

Why should the Na’vi be so disconcertingly humanoid, and so different from the background of their own world?

Of course, looking from the outside at the Avatar universe, we can always point to creative licence. Neytiri, with her catlike features, is sufficiently human to be a sympathetic character, but with a mix of familiar-but-incongruous features to give the audience the sense of the alien. Neytiri trying to hug Jake with four arms might have looked distractingly comical!

But within the Avatar universe observers are puzzled too.

Among the hypotheses to explain the Na’vi’s human-ness are convergent evolution, as we discussed in Chapter 23; perhaps the four-limbed humanoid form is an inevitable end-point of evolution on any world. Or perhaps Na’vi and humans are actually related, through some process of interstellar panspermia, either natural or purposeful. Or, some suspect, maybe a divine hand has been at work; perhaps both we and the Na’vi are the result of a process of intelligent design—but the whole subject of the theological status of the Na’vi is fraught. As yet there is no clear answer. Maybe one of these ideas is right; maybe none is. We have much to learn about the Na’vi, and their world.

However humanoid they are, with their language, art, music, hunting prowess and artefacts, the Na’vi are clearly as intelligent as we are—if not more so, despite our more advanced technologies. And as such encountering them is a fulfilment of a very ancient dream: of finding other minds in the universe.

²⁶ OTHER MINDS

The idea of extraterrestrial intelligence has very deep roots in our culture.

Renaissance thinkers were astounded by Galileo’s first telescopic observation of the moons of Jupiter, a system invisible to the naked eye, yet like a miniature solar system in its own right. As the astronomer Kepler said, “Those four little moons exist for Jupiter, not for us… We deduce with the highest degree of probability that Jupiter is inhabited.”

This powerful intuition of the commonness of life has always caused great controversy, just as it does today. Saint Augustine, for example, long ago decided that aliens couldn’t exist. If they did, they would require salvation—a Christ of their own—but that would contradict the uniqueness of Christ, which is theologically unacceptable.

On the other hand there are some who believe that alien visitors have visited the Earth, and may indeed be among us now. Personally I am sceptical about the UFO narrative. I’ve no doubt that many reported sightings are based on something real and observable—odd atmospheric phenomena, sightings of secretive military projects—but I’ve seen or heard of no firm evidence of any extraterrestrial intelligence behind any reported sighting. And it’s just too hard for me to believe that creatures advanced enough to cross the stars would behave in the secretive, vindictive and downright irrational manner many reports claim…

And yet.

If we aren’t programmed by evolution to register something, maybe we simply don’t see it. There is an apocryphal story that Captain Cook encountered islanders who seemed unable to see his great ships, until the crew launched their smaller, more familiar-looking boats to row to shore. The islanders had never seen such huge structures before, and they simply did not have the conceptual equipment to take them in. Similarly, an alien artefact would be in a different category of object to anything previously encountered by a human being, neither of the natural world, nor created by a human. And if a UFO were to visit the Earth, then perhaps elusive, half-seen glimpses, wrongly interpreted in terms of familiar objects, is precisely the kind of “evidence” we should expect.

But don’t quote me on that.

Today, fully trained scientists armed with the most modern equipment are busily searching for evidence of alien minds.

2010 saw the fiftieth anniversary of Project Ozma, the first modern experiment in SETI (Search for Extraterrestrial Intelligence), when, back in 1960, American radio astronomer Frank Drake listened for alien signals from two stars at one frequency for a week. The idea came from a seminal paper published in Nature in 1959 by two physicists, Giuseppe Cocconi and Philip Morrison, who realised that the then relatively new radio telescopes could be used to send signals between the stars: “Few will deny the profound importance, practical and philosophical, which the detection of interstellar communications would have.” In the last few years I’ve become involved with SETI myself, having joined one of the SETI academic task forces, responsible for trying to imagine the consequences of a detection.

But Frank Drake heard nothing in 1960. And after fifty years, surely the most striking thing about modern SETI is that there have been no positive detections. What’s going on?

Advocates of radio-astronomy SETI point out how limited the searches have been so far; only a small number of stars in a small range of frequency domains for limited times have actually been studied. But there have also been unsuccessful searches for other sorts of evidence, such as artefacts at gravitationally stable points in the solar system. Even distant galaxies have been examined, fruitlessly, for signs of cultivation by super-intelligences, as in the Carl Sagan novel Contact and the Robert Zemeckis movie based on it.

Absence of evidence is not evidence of absence; we can’t yet conclude we are alone. Nevertheless it can’t be denied that the sky is not full of radio-noisy, close-by civilisations, as might have been hoped back in 1960.

A paradox is emerging. In Chapter 22 we looked at the origin of life, and ways life could spread naturally from world to world. Life emerged on Earth about as quickly as it could. If it did so here, why not elsewhere? What’s more, our experience of Earth shows us that if life exists, it spreads wherever it can. The Galaxy is big, but old enough for life to have spread across it many times over, even if it travelled at speeds much less than that of light. So where is everybody? This is a development of a back-of-the-envelope argument first made in the 1950s by the great physicist Enrico Fermi (supposedly in the course of a long lunch). It has become known as the Fermi Paradox: if they exist, we should see them.

Possible resolutions of the Paradox have been extensively explored in science fiction, and in science. Perhaps there is some higher form of existence, as unimaginable to us as a Beethoven symphony is unimaginable to a single neuron in its composer’s brain. Or it may be that there are many species—like the dolphins, perhaps—with intelligence but without the opportunity to develop technology, because they live in an aqueous environment, or are spun out among the great rich interstellar clouds. Or maybe they simply aren’t interested. Frank Drake’s radio telescopes would not detect a trace of the Na’vi, inhabitants of the nearest star system, because they have better things to do than build radio transmitters. Or maybe most advanced technological species blow themselves up, as we’ve come close to doing, or exhaust the resources of their world, as in the “ecocide” of the Avatar future.

But to resolve Fermi you have to believe that everybody is the same; all it would take is one exception, one brash, noisy, expansionist, technological species like ourselves to survive the bottleneck of ecocide and war, anywhere nearby, and we would notice them.

Another class of possibilities is that they are indeed here—but they choose not to be seen by us. This kind of notion is generally known as a “zoo hypothesis.” The UFO mythos is an example of this. In Star Trek, the Prime Directive dictates that junior species should be left alone and given room to grow until they have reached star flight capability. Perhaps they really are here, all around us, concealed in some kind of high-tech duck blinds—hiding from us for good intentions, or bad.

A final possible way to resolve Fermi strikes me as the worst of all. What if there are no Na’vi? What if, despite our intuition to the contrary, we are, after all, truly alone? What if our tiny Earth really is the only harbour of advanced life and mind in the cosmos? We saw in Chapter 23 that multicellular life arose quite late in the story of life on Earth. Intelligent life of our technological kind only arose in the last hundred thousand years or so, a tiny fraction (one forty-thousandth) of life’s duration on Earth. So maybe it only happened just the once, right here.

In which case, surely our first duty is not to wipe ourselves out. For if we allow ourselves to become extinct, the universe will continue to unfold according to the mindless logic of physical law, but there will be nobody even to mourn our passing.

You might ask why we so long to discover the alien. Why do we find the idea of meeting the Na’vi so attractive? And why do we long to talk to them?

I have a personal theory that it’s because we aren’t used to being alone. It’s unusual on Earth for there only to be one species of a class of advanced mammal, as humans are unique. There are many species of monkeys, of whales, even of elephants and chimps. The dolphins have complicated social lives that routinely involve interactions between species.

But we have increasing evidence that in the past we did share the world with many other sorts of hominid. The Neanderthals who died out some thirty thousand years ago were probably our closest cousins, but now there is new and exciting evidence of other sorts of humans surviving until quite recently. The diminutive “hobbits” of Indonesia may have lasted until a mere thirteen thousand years ago, and in March 2010 German scientists discovered a bit of bone from a child’s finger, in a cave in Siberia, that came from yet another hominid species that was still around some thirty thousand years ago. So as recently as that we shared the world with at least three cousins, three other twigs from the bushy human family tree, and I wouldn’t be surprised if the future brings more discoveries of this type.

We evolved in a world full of other human types—not just strangers, but creatures of another sort, with minds somewhere between ours and the chimps’. And now that they’re all gone, we know something is missing from the world, even if we don’t know what it is. Maybe we dream of the Na’vi on their world because they remind us of the vanished cousins on our own.

In the universe of Avatar some, at least, of these questions have been answered. But the discovery of the Na’vi on Pandora was a big surprise in many ways.

Humanity is a young species in a very old universe; it was expected that any intelligences out there, if they exist at all, were probably much older than mankind—and perhaps that very advancement was why we couldn’t perceive them. So nobody expected to find stone age humanoids inhabiting a jungle world orbiting the nearest star. But then, nobody expected to find Jupiter-sized worlds orbiting closer to their stars than Mercury does to the sun. The universe is full of surprises; in a way that’s the point of doing science.

But if we do find the alien, will this dream of the future turn into a nightmare of the past?

²⁷ FIRST CONTACT

Jake Sully’s first meeting with Neytiri is not humanity’s first contact with the Na’vi. That came about when the first unmanned probes landed on Pandora, and blue-tinged faces peered curiously into the camera lenses.

But by then the value of unobtanium had already been realised; RDA was already in operation. And RDA was not best pleased. Loud protests were made that the natives must be protected. Cynics assumed that RDA, more or less beyond the control of Earth, would see the Na’vi as nothing but an obstacle in the way of it achieving its own goals.

Meanwhile the first samples from Pandora were returned to Earth: minerals like unobtanium—and living things, plants, animals, heavily quarantined and controlled, specimens of the flora and fauna for scientific studies and zoos, commercially valuable properties such as the basis of novel drugs.

Wherever we’ve travelled we’ve always brought with us a host of fellow travellers from viruses to rats, “invasive” species that have often done a great deal of damage to native biospheres. Pandora’s environment is not identical to Earth’s, and it’s not clear how easy it would be for terrestrial life to gain a foothold there. But I’m willing to bet that some of our hardiest “extremophile” bugs at least, that can withstand extremes of heat and cold, wet and dry, even radiation baths and oxygen deprivation, could survive there. And what if Pandoran life forms got loose on Earth? Maybe the hardier bugs of Pandora, bred on a tougher world, would prosper here, having evaded all attempts at quarantine and escaped, as living things tend to find a way to do.

And what of the Na’vi? Their genetic material must have been transported to Earth for analysis to support the avatar project. Cadavers were needed for dissection. And perhaps some Na’vi were brought back live.

Imagine the sensation a live Na’vi would have made! These tall, skinny, blue-tinted creatures, as ungainly as giraffes in Earth’s heavy gravity, wearing their own exopacks to enable them to breathe our air… The first Indians brought back to Europe by the conquistadors were a similar wonder. Scientists, historians, anthropologists, linguists and other specialists would have pounced on them. Maybe Na’vi ethnic “fashions” were all the rage for a while.

What might have become of that handful of Na’vi, transported across the light years? Perhaps they would have been taught English, and dressed up in suits and ties to be presented to presidents and monarchs. Or perhaps they would have been cooped up in zoo “habitats” with Pandora-like conditions, while their children were taken off to be experimented on, their genetics pulled apart, their bodies mined for such treasures as their carbon-fibre-reinforced bones. Either way they would have been cut off, not just from their people, their culture, but from Eywa—and from the possibility of joining their ancestors after death (see Chapter 29). And after he died the skeleton of the first Na’vi brought to Earth, no doubt given some human name like “Blue George,” would have been set up on a stand in a natural history museum.

Meanwhile, far away, on Pandora, the conflict we see in Avatar would have begun, and the Na’vi would have started to die at human hands.

Does it have to be that way?

And what if we were on the receiving end?

Certainly, if you’re a fan of peace, love and understanding, the precedent of first contact among human cultures is not encouraging.

In 1492 Christopher Columbus “discovered” a new world, and a whole branch of mankind nobody in Europe had any idea existed before. Just like Avatar’s RDA seeking unobtanium, the monarchs who sponsored the early explorers wanted New World gold and other goods to fund their own projects, notably wars with their Christian rivals and Muslim enemies. Columbus himself was a militant Christian who dreamed of finding a new ocean trade route to Asia, and of joining forces with the Mongol emperors to attack Islam from the east. None of this had anything to do with the Native Americans, but the Europeans had the technology to impose their own agenda on the peoples they found.

Perhaps the most single dramatic moment in the astonishing saga of contact and conquest that followed was the encounter in the Peruvian highlands between the Inca emperor Atahuallpa and the Spanish conquistador Francisco Pizarro, in November 1532, just forty years after Columbus. Atahuallpa ruled the most populous and advanced state in the New World; he had millions of subjects and an army tens of thousands strong. Pizarro led less than two hundred Spaniards. Within minutes of their encounter, Pizarro had captured Atahuallpa. And in a subsequent battle, the Spaniards, with no losses, defeated a native army hundreds of times more numerous, killing thousands. In mere decades the Inca empire had collapsed.

The vast numerical superiority of the Inca meant nothing in the face of the Spaniards’ technological advantage. The Spaniards were a gunpowder culture facing essentially a stone age civilisation. Their steel weapons slashed through the thin armour of the Inca. And the Spaniards’ use of hourses terrified their enemy. As the horse had long been extinct in the Americas, when faced with cavalry charges the Inca did not even understand what they were seeing (remember Captain Cook’s ship and the islanders). Worst of all, in subsequent decades the “herd diseases” like smallpox that the Europeans inadvertently imported from home caused a huge implosion of the native populations.

This basic pattern, of the overwhelming advantage afforded by superior technology, and the leveraging of that advantage into conquest and exploitation, appears to be a common theme of human history. It goes on today. James Cameron intended Avatar as, in part, a cautionary tale about the consequences of contact, colonialism and exploitation. Cameron and some of the cast of Avatar visited the Xingu people of Brazil, who live in a part of Amazonia likely to be affected by the multi-billion-dollar Belo Monte hydroelectric dam project. Cameron calls this a “real-life Avatar confrontation… in progress.”

In the past it has even happened to “us” in the western world. Britain was overwhelmed when the Romans arrived, with their superior army discipline, road-building and literacy-based communications. For all the supposed advantages of Roman civilisation that followed—and Britain’s subsequent history is unimaginable without the Roman intervention—it wasn’t a comfortable process to live through, as Queen Boudicca (Boadicea) of the Iceni nation demonstrated in her bloody but futile revolt a generation after the Romans landed.

If it happened to us before, could it happen again in the future? By the end of the nineteenth century one thoughtful witness, H. G. Wells, disturbed by the plight of peoples like the Tasmanians who appeared to have been entirely exterminated during European colonisation, wondered how it would be if humans, specifically the Victorian-era imperial British, were ever on the receiving end. In The War of the Worlds, British army guns facing the Martian heat ray are “bows and arrows against the lightning”—a phrase evocative of the battle scenes of Avatar.

Today some like to imagine, as in Carl Sagan’s Contact, that if the aliens come we will receive wisdom from the stars: an Encyclopaedia Galactica, a cultural adrenaline boost that will raise our society to new levels. But others follow Wells in imagining harsher possibilities. Physicist Stephen Hawking recently said (in a Discovery Channel documentary called Stephen Hawking’s Universe, aired on 9 May 2010), “I imagine they exist in massive ships, having used up all the resources of their home planet. If aliens ever visit us, the outcome could be much as when Christopher Columbus first landed in America, which didn’t turn out very well for the Native Americans.” Which sounds like an Avatar scenario in reverse.

Today there is a ferocious debate going on in the world of SETI, the search for extraterrestrial intelligence, about the wisdom, not just of passively listening for signals from space aliens, but of signalling to them. This is known as “active SETI.” Earth is a noisy place in the radio spectrum; we’ve been leaking radio, TV and radar signals for decades. But the signal strength drops off quite quickly, over a few light years, spanning a few tens of stars, say. Purposeful signals would suddenly make us visible to a much larger chunk of the Galaxy. And signals have been sent before. In 1974, the Arecibo radio telescope in Puerto Rico transmitted a series of radio pulses towards the M13 star cluster, encoding a message from humanity designed by SETI pioneer Frank Drake.

Some have always been unhappy about this. Former Astronomer Royal Sir Martin Ryle warned that “any creatures out there [might be] malevolent or hungry.” And Sir Bernard Lovell, founder of Jodrell Bank, once said, “It’s an assumption that they will be friendly—a dangerous assumption.” Science-fiction writer David Brin speaks of analogies of toddlers shouting in the jungle. Maybe this is the resolution to the Fermi Paradox: everybody else keeps quiet because they know there is something dangerous out there.

But does it have to be this way? Is it in us to learn to love the alien? And could the alien ever love us?

At least we know we ought to behave better.

The “Golden Rule” of ethics, which is embedded in many religions and philosophies, was expressed by Christ this way: “Do unto others as you would have them do unto you.” (This wording, a version of verses from the gospels of Matthew and Luke, first appeared in a catechism in the sixteenth century.) Also known as the “ethic of reciprocity,” the Golden Rule is arguably the basis for the modern concept of human rights: that you should treat everybody, including those not in your own immediate allegiance group, with consideration. It has been criticised. George Bernard Shaw pointed out that the other’s taste may not be the same as yours; how do you know that the others would like having done unto them what you want done unto you. But nevertheless it’s not a bad principle to live by. As Wells pointed out, the imperial British wouldn’t have enjoyed having the Martians doing unto them what the British did to the Tasmanians.

Even during the darkest years of the European colonisation age, there were flickers of empathy. As early as Columbus’ own expeditions, some people back home were appalled by accounts of slavery and massacre. It wasn’t long before the Pope decreed that the Native Americans were fully human, that they had souls, and that the mission of Christians must be to save those souls rather than exploit their bodies. The Christians missionaries that followed did a good deal to disrupt and destroy native culture, but in the context of the sixteenth century I think you must call the Pope’s decree a hopeful sign.

Interesting debates continue today, incidentally, about the theological status of hypothetical extraterrestrial aliens. There is no sign of any Christian or other missionaries working among the Na’vi. The collision with Eywa would be fascinating. Perhaps it might help the Na’vi’s cause if some twenty-second century Pope in faraway Rome were to declare that they too have souls…

But the Na’vi aren’t exotic humans, like the Native Americans. They are alien creatures. We can empathise with human strangers; could we ever empathise with the alien?

Again, precedents from our career on Earth aren’t very hopeful. Consider how we treat the animals. Though the Na’vi respect the animals they take for food, on Earth even our closest surviving relatives, the great apes, are in danger of being driven to extinction through the carelessness of habitat loss and fragmentation—and, sadly, from purposeful hunting.

We tend to measure animals’ worth in terms of how much they are “like” us. Thus we look for signs of human-like cognition in chimps, as expressed in tool-making and sign language. But maybe, as philosopher Jeremy Bentham said as long ago as 1789, we should treat an animal depending not on how well it thinks but on how much it is capable of suffering. Consider the heartbreak of a mother elephant when her baby is taken by the poachers. Scottish psychologist James Anderson has compiled data on how chimps treat their dead. Mothers can carry corpses of their dead babies around for weeks, even though it is clear from subtle reactions that they know the infants are dead. Such observations “make a strong case that chimps not only understand the concept of death but also have ways of coping with it,” Anderson says.

You only have to consider your own feelings when watching the distressing scenes that follow the aftermath of the destruction of the Na’vi’s Hometree to believe, I think, that we will indeed be able to empathise with the alien, when we meet it. After all, though in Avatar there is a Miles Quaritch, there is also a Grace Augustine, wanting to reach out to the Na’vi.

But it would surely make it easier to empathise with an animal if you could plug your mind directly into it.

²⁸ MIND TO MIND

One way in which the Na’vi are entirely unlike us is in their queues.

A queue is a hair braid encasing a neural whip, an intricate mass of active neural tendrils. The Na’vi are able to join this organ to similar structures on other animals to make a neural bond, which the Omaticaya call the shahaylu. Onscreen we see this work with the direhorse, the banshee and the leonopteryx. Through his bond with his direhorse, avatar-Jake can sense the animal’s body, her heartbeat, her breath, the strength in her legs. And his will to some extent overpowers that of the linked animal. At first he commands her with words, but ultimately he is able to control the direhorse with inner “commands,” just as he controls his own body.

As well as a very visible demonstration of the Na’vi’s integration into their ecology, this is clearly a terrifically useful biological technology. It is like a natural version of the comprehensive neural interfaces that must be necessary to run Jake’s avatar body, as we’ll see in the next section. Perhaps avatar technology was in part inspired by the natural version on Pandora.

But we might speculate that in some ways the shahaylu has stifled Na’vi cultural evolution. If you can will a direhorse into submission you don’t need to break it. Perhaps the generations-long process of domestication with which humans have filled their world with more “useful” versions of animals like horses, sheep, cattle and dogs will never occur to the Na’vi.

What’s of more interest to us amateur xenobiologists, however, is how the neural link evolved.

The shahaylu is even more remarkable when you consider what diverse animals it links: Na’vi, direhorse, banshee. Humans are fairly remote relations to horses, and even more remote from birds and pterosaurs. As life on Earth evolved, the family of primates that would one day include humans split off from the “laurasiatheres,” the tremendous group that includes horses (along with camels, pigs, dogs, cats, bears…) as far back as eighty-five million years ago. This wasn’t even in the time of the mammals’ dominance; this was back in the Cretaceous age, the dinosaur summer before the big impact. And we split off from the group that includes leathery flying lizards such as the pterosaurs (and indeed the birds) even further back in time: an astounding three hundred million years ago, back in the Carboniferous age, halfway back to the time of the emergence of multicellular life in the first place. If similar evolutionary gulfs separate Na’vi from direhorse and banshee, how is it possible for them to develop such an intimate link as the shahaylu?

I can think of one terrestrial parallel: bees and flowers.

Like a bee pollinating a flowering plant on Earth, a Pandoran direhorse has a long snout it uses use to feed on sap drawn deep from plants like the direhorse pitcher. Both halves of the partnership benefit. The direhorse gets protein from insects trapped in the sap, and the pitcher plant gets pollinated. This behaviour is shared by some terrestrial animals, such as lemurs and possums. In some senses the link between bee and flower (and direhorse and pitcher plant) is a lot more fundamental even than the shahaylu. The bee has come to rely on the plant nectar for food, and the plant entirely relies on the bee for its means of fertilisation. This cooperation is not just a temporary alliance for horse-riding, but determines life and death for both partners.

But there had been insects around for three hundred million years before the flowering plants, the angiosperms, first appeared on the Earth back in the Cretaceous, the heyday of the dinosaurs. And the split between the plants and the vast family that includes all animals, insects and fungi was extraordinarily far back in time—billions of years ago. But once the flowering plants emerged, they co-evolved with the insects they cooperated with, establishing their extraordinarily intricate interdependence over millions of years.

So it is possible for astonishingly distantly related species to develop a remarkably close degree of cooperation, given enough time for natural selection to work. Perhaps something like this lies behind the shahaylu.

But for a Na’vi, whatever its origin, the neural queue is intimately linked to her experience of sex and death.

To quote the 2007 screenplay: “Neytiri takes the end of her queue and raises it. Jake does the same, with trembling anticipation. The tendrils at the ends move with a life of their own, straining to be joined… The tendrils intertwine with gentle undulations. Jake rocks with the direct contact between his nervous system and hers. The ultimate intimacy. They come together into a kiss and sink down on the bed of moss, and ripples of light spread out around them…”

The love-making between avatar-Jake and Neytiri is the culmination of their strange courtship. The joining of their neural queues is fundamentally involved; this is a joining of minds, of consciousnesses, as well as bodies. And as we see onscreen the outcome of this joining is a lifelong, irrevocable bond, cementing the culture’s monogamy.

But for a Na’vi warrior a queue is also a weakness. At the climax of the battle between RDA and the Na’vi there is a brutal fate for the warrior Tsu’tey, when a human soldier brutally cuts off his queue. The human has heard this is “worse than death” for a Na’vi. Perhaps it would be. Tsu’tey could no longer ride a direhorse or banshee. He would be excluded from sexual intimacy; this is a symbolic castration.

And, worse, Tsu’tey will suffer a deeper death than his ancestors. For his queue is also his connection to Pandora’s greatest mystery of all: Eywa. And through her, immortality.

²⁹ EYWA

As Selfridge and Quaritch prepare to use lethal force against the Omaticaya and their forest, Grace Augustine protests, trying vividly to express what she believes she has learned of Eywa.

Grace has found evidence of “electrochemical communication” between the roots of Pandora’s trees, similar, she thinks, to the synaptic sparking between the neurons in a human brain. This is the basis of a natural neural network, like a human brain, but on a planetary scale: Eywa.

To the Na’vi, Eywa is their mother goddess—and, in a sense, their heaven. She takes them into herself when they die. We see this when the transfer of the essence of dying Grace to her avatar body is attempted in the Tree of Souls. This fails—but “all that [Grace] is” is taken into Eywa. Some essence of the dead Na’vi survive within Eywa, and the living can communicate with them by plugging a queue into a natural “portal” such as the Tree of Voices. This is why the amputation of Tsu’tey’s queue was so cruel; worse even than murder, it denies him immortality among his ancestors.

If Eywa were a human computer, all this is plausible if you believe in the much-anticipated technologies of “mind uploading”—mapping the brain and transferring its contents to a computer store—which we will look at in the next section when we investigate the avatar link process itself. But Eywa isn’t a Cray supercomputer. She has no silicon chips or optical links. She’s not even a human brain, a mesh of intricate biochemistry. As Parker Selfridge protests, “What the hell have you people been smoking out there? They’re just. Goddamn. Trees.”

Is it really plausible that a bunch of trees could be connected up into a network with anything like the “functionality” of a brain? And even if you believe a forest can become a brain, how smart can it possibly be?

Let’s start with Grace’s numbers.

Grace says that each tree on Pandora has “ten to the fourth” connections to the trees around it, and there are “ten to the twelfth” trees on the moon. This, she says, adds up to a global neural network with more connections than the human brain.

Can there really be “ten to the twelfth” trees on Pandora? Ten to the twelfth power means ten multiplied by itself twelve times, a number you’d write down as one followed by twelve zeros, with commas scattered according to taste: 1,000,000,000,000. That’s a million million—a trillion. By comparison, how many trees are there on Earth? In 2008 Nalini Nadkarni of Evergreen State College in Washington published an estimate, based on NASA orbital images of forest coverage. Her number was absurdly precise: 400,246,300,201—four hundred billion, or around sixty trees for every person on the planet. That’s about half of Grace’s estimate for Pandora. And given that much of Earth has been deforested by us humans in the last few thousand years, that’s close enough for me to accept Grace’s number as plausible, even though Pandora is smaller than Earth. Meanwhile the human brain is believed to contain around a hundred billion neurons—that’s ten to the power of eleven in Grace-speak. That’s a factor of ten less than Grace claims for Pandora’s tree number. As regards connections, on average a brain neuron has about a thousand connections to neighbouring neurons: that’s ten to the third, again a factor of ten less than Grace claims for the trees.

So your brain amounts to a total network of around a hundred trillion connections (a hundred billion times a thousand). And on that count, Grace is right that the network on Pandora is indeed bigger than the human brain, by a factor of about a hundred.

How does this compare to modern computers? Each neural connection in your brain can support about two hundred “calculations” per second. So that’s a total of twenty thousand trillion calculations per second, going on in your head, right now. (Granted it may not always feel like it.) That is, in the information technology terms I used in Chapter 19, the brain is capable of twenty petaflops. As we saw in Chapter 19, as of 2010 the most powerful non-distributed computer system in the world, the Chinese “Milky Way,” was capable of 2.5 petaflops—an eighth of the processing speed of the human brain, or about a thousandth the power of Eywa.

That sounds impressive, but you’ll recall from Moore’s Law (Chapter 19) that computing speeds and capacities are multiplying rapidly, doubling every fourteen months according to the TOP500 study. If this goes on, the fastest computer will pass the brain for sheer speed in just four more years—and it will pass the more powerful Eywa in a mere dozen years.

Or will it?

Grace’s estimate of Eywa’s complexity is based on a count just of the physical neural network of trees and their connections. This is quite reasonable from a scientist’s point of view, since it is all that Grace can “sample” and measure. But there is more to the complexity of any computer than a simple count of the links between its components.

One possibility is that the trees themselves are more than simple switches; perhaps they contain some internal processing too—which would up Eywa’s total processing power significantly. There is in fact a theory that the neurons in our brains are similarly more than simple on-off switches. Cambridge biologist Brian J. Ford is developing holistic theories about cells, which are complex organisms in their own right, and are capable of remarkably complex individual behaviours. Amoebas, for example, single-celled organisms, can build glassy shells by picking up sand grains from the mud. The cells of our bodies can perform similarly complex acts in support of body functions. Why, then, asks Ford, should we not expect that some kind of processing goes on within neurons, brain cells, themselves? Even the details of their output firings seem to include delays, nonlinear responses and other subtleties. “My hunch,” says Ford, “is that the brain’s power will turn out to derive from data processing within the neuron rather than activity between neurons.”

And what about connections beyond the intertwining of trees roots? The woodsprites are “the seeds of the sacred tree.” When they settle on avatar-Jake, during his first encounter with Neytiri, the Na’vi girl takes it as a sign from Eywa of great significance. But we see no physical connection between the trees and the woodsprites, no obvious neural links—and nor, indeed, have we any hint of how Eywa can predict Jake’s future. And later during the SecOps attack, the animals of Pandora, the viperwolves, banshees, hammerheads and thanators, join in the fightback. This is another expression of the will of Eywa, but again we see no evidence of a simple physical connection between trees and animals. In another odd incident, Mo’at, as tsahik, the shaman, presumably the closest of all the Na’vi to Eywa, tastes Jake’s blood on first encountering him. Is she sampling some kind of biochemical data to transfer to Eywa?

There’s clearly much to Eywa that isn’t obvious. But we do witness one remarkable expansion of Eywa’s apparent power beyond the limit of the core forest infrastructure.

In the Tree of Souls, when Grace and Jake are being taken into the Eye of Eywa to be transferred to their avatar bodies, the Na’vi of the Omaticaya clan all plug their queues into a glowing, dispersed root mass in the ground. The clan evidently becomes a kind of internet of the mind, with distributed computing going on in the “PCs” of the Na’vi brains in addition to the “mainframe” processor of the tree network.

Such networks can be extraordinarily powerful. According to an estimate published by Wired Magazine in June 2008, the billion PCs that are today connected by the Internet—along with smart phones, tablets and a host of other devices—amount to a single computer with a power equivalent to twelve thousand petaflops. That’s thousands of times the power of that top-end Chinese machine. A project called SETI@Home is an example of how this distributed power can be used. SETI searches of radioastronomy data for signals from extraterrestrial intelligences can be very hungry for computing power; there is a lot of sky to search and a lot of radio frequencies to listen on. Since the 1990s the task of sifting through the tremendous volumes of raw data has been parcelled out to a network of volunteers’ PCs, each of which contributes a fraction of its total power to the SETI quest. It’s an attractive project that offers you the chance of being the one to make first contact, at home…

To some extent a physical networking as in the Tree of Souls scenes is the ultimate expression of the Na’vi’s close sociability with each other—yet it’s much more than that. How must this linking feel? What would it be like, to be part of an internet of the mind?

A group mind might be a new layer of processing, superimposed on top of the central nervous systems of each of its members, passing information in a different, faster way. It would be a growth of consciousness, perhaps like the mind-expanding feeling you get when solving a puzzle, or finding the right strategy in a chess game—or when a scientist sees her hypothesis confirmed by a bit of new evidence, and the world makes a little more sense than it did before. Joined in Eywa, you would no longer be alone. You would share thoughts, feelings, memories. What would it matter if some of those memories were now stored outside your own skull?

And for the Na’vi, united in Eywa, this may have the strange consequence that to some extent the spirits of the ancestors are stored in the brains of their living descendants.

Eywa as a computing system is worthy of deeper study, for it shows signs of great sophistication in her processing and decision-making. The biochemical communication of the tree roots cannot be terribly fast, so planetary-scale Eywa may have a distributed decision-making system. When the woodsprites first detect there is something special about avatar-Jake, a holding decision seems to be made about him—Neytiri is instructed to keep him from harm—while, perhaps, the news is passed to higher levels of the hierarchy, and a deeper decision made. Later, Eywa clearly responds to the mass appeals of the combined clan, but she has options; there are clearly occasions when she feels it right to promote an individual. This is the Toruk Macto phenomenon, culminating in the selection of Jake himself.

But however smart she is, where did Eywa come from? How did she evolve?

Eywa is central to the Na’vi and their world. Jake learns that the Na’vi see the world as a network of energy, flowing through all living things; the energy is only borrowed, and you have to give it back. Eywa, the great mother, is at the centre of all this; she protects the “balance of life.” As such, perhaps she is a sister to our own Gaia.

As we saw in Chapter 2, according to theories developed first by James Lovelock, we believe that the Earth—its crust, the atmosphere, the water in the oceans and rivers and suspended in the air, and the biosphere, the world’s great cargo of living things—is a single, complex, highly interconnected system, constantly in flux under the pressure of powerful forces: the sun’s radiant energy which produces wind and rain and feeds life through photosynthesis, and Earth’s internal engine, principally the movement of the great tectonic plates and the outgassing of volcanoes. These forces drive tremendous cycles of mass and energy. And these unending cycles keep Earth habitable.

The main long-term challenge faced by life on Earth is what astrophysicists call the “Young Sun Paradox.” The sun, like all similar stars, is slowly brightening as it ages. In Earth’s early history the sun’s power output was only some seventy per cent of its current value. But despite this, as far back as we can see, temperatures on Earth’s surface have stayed about the same. Yes, there have been Ice Ages, but we have evidence from geology that on the whole liquid water has been able to exist on Earth’s surface for almost all of its history. Faced with a relentlessly brightening sun, some mechanism seems to have maintained the mean surface temperature of Earth in a range suitable for liquid water, and thus equable for life.

The key turns out to be carbon dioxide, the notorious “greenhouse gas” largely responsible for our current pulse of global warming. Carbon dioxide is injected (naturally) into the air by outgassing from volcanoes and other tectonic phenomena. It is removed by weathering, as the gas combines chemically with surface rocks, and by living processes; the bulk of the carbon in a tree trunk is drawn down from the air.

The outgassing is more or less constant, but the weathering rate and the productivity of life change with temperature. And because of that temperature dependence a global feedback mechanism has been operating, apparently for aeons. As the sun heats up, the carbon dioxide concentration is reduced, so that less heat is trapped, and overall the surface temperature stays constant.

This, and a number of other biochemical and geochemical feedback cycles, led Lovelock to formulate his Gaia hypothesis, that life has the ability actively to control its environment on a planetary scale, and thus to cope with changes such as the heating up of the sun. And all this emerged through self-organisation, as a natural outcome of the general increase of complexity on the planet. Lovelock’s ideas were greeted by a storm of scepticism, but the records of the evenness of temperatures in the past, and similar data, seem unarguable.

(This can’t go on for ever, though. When there is no more carbon dioxide left to draw down, the warming will at last be uncontrollable and the biosphere will gradually collapse. This will happen in less than a billion years. And remember that life on Earth is already some four billion years old. Gaia is old, not young, and Earth is closer to becoming a Mars-like desiccated world, like Burroughs’ Barsoom, than you might think.)

In the case of Gaia as we understand her, there seems no need for mind to be involved, no intention. “Gaia” is not alive. But what of Eywa?

Consider this. Alpha Centauri is an older star system than the sun, by some two hundred and fifty million years. That is a long time—four times as long as the gap between us and the dinosaurs—long even compared to the time there has been multicelled life on this planet, nearly half of that great span. So Pandora is most likely an older world than Earth, and its biosphere that much older too. And so Eywa must be older than Gaia.

Eywa, meanwhile, in preserving Pandora as a habitable world, has had significantly greater challenges to face than Gaia had. As a hazard, the slow heating-up of the sun has been relatively easy for Gaia to deal with; Gaia has had to become no smarter than a vast natural thermostat. Alpha Centauri A is heating up just as the sun is. But Pandora also suffers the tectonic agony of Polyphemus’ tides, and the tumultuous radiative and magnetic environment caused by its own magnetosphere and Polyphemus’. So Eywa has had to become a good deal more complex than Gaia—but has had the time to evolve ways to face its tougher challenges.

And, in the end, perhaps there was a sparking of consciousness, in a global network of ten to the twelfth trees.

All this is just my speculation. Perhaps the truth is entirely different. We have much to learn of Eywa, her true nature, her origin, and her ultimate destiny.

To paraphrase the British biologist J. B. S. Haldane, the universe is probably not just stranger than we imagine, but stranger than we can imagine.

That is surely true of Pandora. And this strange and remarkable world, Pandora, these remarkable people, the Na’vi, are what Jake Sully encounters when he enters the avatar link unit—and, astonishingly, looks out through the eyes of a body not his own.