Phase Space (39 page)

Mary followed Nemoto, catching her easily.

Soon they saw the Running-folk.

There were many of them, men, women, children. They had broken their lifelong trek at a river bank. They were splashing water into their mouths, and over their faces and necks. The children were paddling in the shallows. They were all naked, all hairless save for thatches on their scalps and in their groins and arm-pits.

They would never have been considered beautiful by a human, for their legs were immensely long and their chests expanded behind huge rib cages, giving them something of the look of storks. But they had the faces of their
Homo erectus
ancestors, small and low-browed with wide, flat nostrils.

And Nemoto was stalking towards this gathering, waving her arms and brandishing her weapons. ‘Get away! Get away from there, you brutes!’

Some of the adults got to their feet, their legs unfolding, birdlike. Mary could hear their growls, though she and Nemoto were still distant.

The first rock – crudely chipped, as if by a child – landed in the dirt at their feet.

Mary grabbed Nemoto’s arm. Nemoto struggled and cursed, but Mary held her effortlessly. She dragged Nemoto back out of range of the stones.

The Runners settled again to their bathing and drinking. They stayed where they were for most of that long day, and so did Nemoto, squatting in the dirt with scarcely a motion, staring at the Runners.

Mary stayed with her, growing increasingly hot and thirsty.

At last, as the evening drew in, the Runners got to their feet, one by one, picking up their long hinged legs. And then they began to move off along the river. They became lanky silhouettes against the setting sun, and the river gleamed gold.

Nemoto stalked down towards the river.

Here, just where the Runners had settled, there was a shell of white and black, cracked open. It was the thing Nemoto called a
lander.
Once, Nemoto had used it to bring the Hams here, to the Grey Earth, to home. Nemoto clambered inside the shattered hull. After so many cycles of the Grey Earth’s ferocious seasons, there was little left of the interior equipment now. Mary saw how birds and wasps and spiders had made their home here, and grass and herbs had colonized the remnants of the softer materials.

Mary thought she understood. Though it had been broken open the moment it had fallen to the ground, Nemoto had done her best to protect and preserve the wreck of the lander. Perhaps she wanted it to take her home.

But the lander remained resolutely smashed and broken, and Nemoto could not even persuade the people to get together to haul it away from the river.

As the light seeped out of the sky, Nemoto, at last, came away from the wreck. Mary took her arm, and shepherded her quickly towards the security of the cave, for the predators hunted at sunset.

It proved to be the last time Nemoto ever left the community.

I do not know how this came to be, this manifold, this cosmic panoply, this proliferation of realities.

There is a theory that our universe grew from a seed, a tiny piece of very high-density material that then inflated into a great volume of spacetime, with planets and stars and galaxies. This was the Big Bang. But perhaps that seed was not unique. Perhaps there is a sea of primordial high-density matter-energy – a sea where temperatures and densities and pressures exceed anything in our universe, where physics operates according to different laws
–
and within this sea universes inflate, one after another, like bubbles in foam. These bubble-universes would have no connection with each other. Their inhabitants would see only their own bubble, not the foam itself.

That is my legend. The Hams’ legend is that the Old Ones created it all. Who is to say who is right? How could we ever know
?

Whatever the origin of the manifold, within it there could be an infinite number of universes. And in an infinite ensemble, everything which is logically possible must – somewhere, somehow – come to pass.

Thus there must be a cluster of bubble-spaces with identical histories up to the moment of Earth’s formation, the Big Whack
–
and differing after that only in the details of the impact itself,
and their consequences. I imagine the possible universes arrayed around me in phase space. And universes differing only in the details of the Earth-Moon impact must somehow be close to ours in that graph of the possible.

I know this from personal experience.

For me it began when a new Moon appeared in Earth’s sky: a fat Moon, a Red Moon, replacing poor dead Luna. I travelled to that Moon on a quixotic jaunt with Reid Malenfant, ostensibly in search of his lost wife, Emma Stoney. There we encountered many hominid forms – some more or less human, some not – all refugees from different reality strands, swept away by that Red Moon, which slides in sideways knight’s moves between universes.

Just as Malenfant and I were swept away, when my own Earth, Blue Earth, disappeared from the Moon’s sky. I knew immediately that I could never go home.

To fulfil a pledge foolishly made to these Hams by Emma Stoney, I agreed to use our small Earth-Moon ferry spacecraft to carry the Hams back to their Grey Earth – when the opportunity presented itself, as our wandering Moon happened that way. Once I was off the Red Moon, with a spacecraft, I vaguely imagined that I would be able to go further, to get away from the deadening menticulture that rapidly emerged among the stranded on the Red Moon. But it was not to be; I crashed here, and when the Red Moon wandered away from the sky, I was left doubly stranded.

The Red Moon is an agent of human evolution. That is why it wanders. Its interstitial meandering is a mixing device, an artefact of the Old Ones, who may even have manufactured this vast mesh of realities.

So I believe.

But whatever the purpose of that Moon’s wandering, it destroyed my own life.

For the Hams, for Julia, the Grey Earth is home. For me, this entire universe is a vast prison.

The air grew hotter yet, approaching its most violent peak of temperature, even though the sun still lingered beneath the horizon for part of its round, even though night still touched the Grey Earth. Soon the fast-growing grasses and herbs were dying back, and the migrant animals and birds had fled, seeking the temperate climes.

The season’s last rain fell. Mary closed her eyes and raised her open mouth to the sky, for she knew it would be a long time before she felt rain on her face again.

The ground became a plain of baked and cracked mud.

The people retreated to their cave. Just as its thick rock walls had sheltered them from the most ferocious cold of the winter, so now the walls gave them coolness. And just as the people had drawn warmth from the sap of the blood-tree, pumped up from the ground, now the tree let its sap carry its excess heat down into the ground, and its tangle of roots cooled the cave further.

The people ate the meat they had dried out and stored in the back of their cave, and they drank water from the drying rivers and lakes, and dug up hibernating frogs, fat sacks of water and meat that croaked resentfully as they were briskly killed.

Nemoto could not leave the cave, of course. Long before the heat reached its height, her relentless illness had driven her to her pallet, where she remained, unable to rise, with a strip of skin tied across her eyes. But Mary brought her water and food.

At length there came a day when the sun failed even to brush the horizon at its lowest point. From now on, for sixty-eight days, it would not rise or set, but would make meaningless circles in the sky, circles that would grow smaller and more elevated.

The Long Day had begun.

And still the great blood-tree grew, drinking in the endless light of the sun and the water it found deep beneath the ground, so that sometimes the roots that pierced the cave writhed like snakes.

Here is how, or so I have come to believe, this Red Moon has played a key role in human evolution.

Consider. How do new species arise, of hominids or any organism
?

Isolation is the key. If mutations arise in a large and freely mixing population, any new characteristic is diluted and will disappear within a few generations. But when a segment of the population becomes isolated from the rest, dilution through interbreeding is prevented. Thus the isolated group may, quite rapidly, diverge from the base population. And when those barriers to isolation are removed, the new species finds itself in competition with its predecessors. If it is more fit, in some sense, it will survive by out-competing the parent stock. If not, it declines.

When our scientists believed there was only one Earth, they
developed a theory of how the evolution of humanity occurred. The ape-like bipeds called Australopithecines gave rise to tool users, who in turn produced tall erect hairless creatures capable of walking on the open plain, who gave rise to various species of
Homo sapiens –
the genus that includes myself. It is believed that at some points in history there were many hominid species, all derived from the base Australopithecine stock, extant together on the Earth. But my kind –
Homo sapiens sapiens –
proved the fittest of them all. By out-competition, the variant species were removed.

Presumably, each speciation episode was instigated by the isolation of a group of the parent stock. We assumed that the key isolating events were caused by climate changes: rising or falling sea levels, the birth or death of forests, the coming and going of glaciation. It was a plausible picture – before we knew of the Red Moon, of the Grey Earth, of other Moons and Earths.

Assume that the base Australopithecine stock evolved on Earth
–
my Earth. Imagine that some mechanism scooped up handfuls of undifferentiated Australopithecines and, perhaps some generations later, deposited them on a variety of subtly different Earths.

It is hard to imagine a more complete isolation. And the environments in which they were placed might have had no resemblance to those from which they were taken. In that case our Australopithecines would have had to adapt or die.

And later, samples of those new populations were swept up in their turn, and handed on to other Earths, where they were shaped again. Thus the Hams, with their power and conservatism, have been shaped by the brutal conditions of this Grey Earth.

This is my proposal: that hominid speciation has been driven by the transfer of populations between parallel Earths. It is fantastic, but logical.

If this is true, then everything about us – everything about
me –
has been shaped by the meddling of the Old Ones, these engineers of worlds and hominids, for their own unrevealed, unfathomable purpose. Just as my own life story – too complicated to set out here – has become a scrawl across multiple realities.

What remains unclear is why the Old Ones, if they exist, should wish to do this. Perhaps their motives were somehow malicious, or somehow benevolent; perhaps they wished to give the potential of humankind its fullest opportunity of expression.

But their motive is scarcely material.

What power for mortals to hold.

What arrogance to wield it.

Nemoto said she would not go into the ground until she saw another night. But she grew steadily weaker, until she could not raise her body from its pallet of moss, or clean herself, or even raise her hands to her mouth.

Mary cared for her. She would give Nemoto water in sponges of mashed-up leaf, and when Nemoto fouled herself Mary cleaned her with bits of skin, and she bathed her body’s suppurating sores with blood-tree sap.

But Nemoto’s skin continued to flake away, as the slow revenge of the bat disturbed from its hibernation took its gruesome course.

There came a day when the sun rolled along the horizon, its light shimmering through the trees which flourished there. Mary knew that soon would come the first night, the first
little
night, since the spring. So she carried Nemoto to the mouth of the cave – she was light, like a thing of twigs and dried leaves – and propped her up on a bundle of skins, so that her face was bathed in the sunlight.

But Nemoto screwed up her face. ‘I do not like the light,’ she said, her voice a peevish husk. ‘I can bear the dark. But not these endless days. I have always longed for tomorrow. For tomorrow I will understand a little more. I have always wanted to
understand.
Why I am here. Why the world is as it is. Why there is something, rather than nothing.’