Xeelee: An Omnibus: Raft, Timelike Infinity, Flux, Ring (158 page)

Spinner made out the central galaxy group. It was a grey, grainy cloud of light. ‘Fascinating.’

‘Oh, come on, Spinner. Look, we’re making an epic journey here - we’re travelling so far we’re making progress through the large-scale structure of spacetime. You can’t fail to be - well,
uplifted
.’

‘But I can’t
see
any of it, Louise,’ Spinner said fretfully.

Louise was silent for a moment. Then she said, ‘All right, Spinner. I’ll
show
you where you are.’

A ball of brilliant white light, expanding rapidly to about a foot across, appeared a few yards in front of the ‘fighter cage.

Spinner slouched in her couch and folded her arms. ‘Another educational Virtual display, Louise?’

‘Bear with me, Spinner-of-Rope. Look at this. Here’s the Universe, expanding from the Big Bang - as it was after perhaps three hundred thousand years. The cosmos is a soup of radiation and matter - a mixture of the dark and light variants.

‘The temperature is still too high for atoms to form. So the baryonic matter forms a plasma. But plasma is quite opaque to radiation, so the pressure of the radiation stops the matter from clumping together. There are no stars, no planets, no galaxies.’

Abruptly the Virtual Universe expanded to double its size, and turned clear; a flash of light flooded out over Spinner’s face, making her blink.

‘Now the temperature has fallen below three thousand degrees,’ Louise said. ‘Suddenly the electrons can combine with nuclei, to form atoms - and atoms
don’t
interact strongly with photons. So the Universe is transparent for the first time, Spinner. The radiation, free to fly unhindered across space, will never interact with matter again. And in fact we can still see the primordial radiation today - if we care to look, its wavelength greatly stretched by the expansion of the Universe - as the cosmic background microwave radiation.

‘But the key point is, Spinner, that after this decoupling the radiation could no longer stop the matter from clumping together.’

The model Universe was now a cloud of swarming, jostling particles.

‘It looks like a mist,’ Spinner said.

‘Right. Think of it as like a dew, Spinner. It’s spread out thin and uniform: on average there’s one hydrogen atom in a space the size of one of our transport pods. And at this point the expansion of the Universe is pushing the dewdrops still further apart. But now, the structures of matter - the galaxies, the clusters and superclusters of galaxies - are ready to coalesce; they’ll condense out like dewdrops on a spider web.’

Spinner smiled. ‘Some spider. But where’s the web?’

The ball of mist was filled, now, by a fine tracery of lines; the toy Universe looked like a cracked, glass sphere. ‘
Here’s
the web, Spinner,’ Louise said. ‘You’re looking at
cosmic strings
. Strings are defects in spacetime—’

‘I know about string,’ Spinner said. ‘The Xeelee used strings - and domain walls - in the construction of the nightfighter.’

‘Right. But
these
strings formed naturally. They are remnants of the phase transitions of the early Universe, remnants left over after the decomposition of the GUT unified superforce which came out of the singularity . . . Cosmic strings are residual traces of the ultrahigh, symmetric vacuum of the GUT epoch, embedded in the “empty space” of our Universe - like residual lines of liquid water in solid ice. And the strings are superconducting; as they move through the primordial magnetic fields, huge currents - of a hundred billion billion amps or more - are induced in the strings . . .’

The strings writhed, like slow, interconnected snakes, across space. The particles of mist, representing the uniform matter distribution, began to drift towards the strings. They coalesced in narrow columns around the strings, and in thin sheets in the wake of the strings.

‘It’s beautiful,’ Spinner said.

‘The strings are moving at close to lightspeed,’ Louise said. ‘They leave behind them flat wakes - planes towards which matter is attracted, at several miles a second. Structure starts to form in the wakes, so we get a pattern of threads and sheets of baryonic matter surrounding voids . . .’

Now the baryonic matter, coalescing around the string structure, imploded under its own gravity. Tiny Virtual galaxies - charming, gem-like - twinkled to life, threaded along the webbing of cosmic string.

‘And there’s more,’ Louise said. ‘Look at this.’

Now there was a
loop
of cosmic string, twisting in space and oscillating wildly.

‘String loops can form, when strings cross each other,’ Louise said. ‘But they’re unstable. When loops form they decay away rapidly . . . unless they are stabilized, as the Xeelee have made stable their nightfighter wings. Now: remember I told you that the strings are superconducting threads, carrying immense electrical currents? When the strings decay, all that electromagnetic energy has to go somewhere . . .’

Abruptly the loop shrank, precipitately, and once again light blasted into Spinner’s face.

Spinner lifted her hand to her faceplate. ‘I wish you’d stop doing that,’ she said.

‘Sorry. But
watch
, Spinner. See what’s happened?’

Spinner dropped her hand and blinked dazzled eyes.

The explosion of the loop of string had blown out a huge hole, in the middle of the mesh of galaxy threads.

Spinner nodded. ‘I get it. There’s a pulse of electromagnetic energy, which blows a bubble in the clouds of matter.’

‘Not quite,’ Louise said. ‘Spinner, remember that dark matter is
transparent
to photons - to electromagnetic radiation. So the loop’s electromagnetic pulse blows out just the
baryonic
matter; it leaves a hole, filled by dark matter but scoured clean of star stuff.

‘Spinner, all this cosmic engineering induced by the strings - the primordial seeds - has left us with a
fractal
structure.
Fractal
means the foam has the same general structure at all scales. It
looks
the same, no matter how far out or how close in you study. Our Galaxy is part of a small cluster - the Local Group - which, together with several other clusters, is part of a supercluster called the Virgo Cluster . . . which in turn—’

‘I get the idea,’ Spinner said.

‘The baryonic matter is clustered in filaments and sheets, around huge voids filled only with dark matter. It’s like a froth, Spinner - and it’s a very active froth, like an ocean’s surface, perhaps; the strings are whipping through space at near lightspeed, and so there are huge movements, currents in the foam.’

‘Louise, you said you’d show me where
I
am.’

‘All right, Spinner . . .’

Below the glistening glass the curves of the nightfighter rippled like some immense sculpture. There was Xeelee construction material only feet away from her now, and Lieserl had an urge to reach out and stroke it, as if the ‘fighter were some immense, caged animal. But the material was separated from her both by the base of the lifedome and by a layer of hard vacuum - and, she thought ruefully, by a layer of unreality which only Mark Wu and his gadgets could breach.

‘You’re thoughtful,’ Milpitas said.

She rubbed her chin. ‘I was thinking how very
alive
this Xeelee ship looks. Not like a piece of technology at all. This is like some immense ocean beast, trapped beneath a frozen surface; it’s as if I can see
muscles
beneath that skin of construction material.’

Milpitas grunted. ‘It’s an attractive image,’ he said dryly. ‘Although I’m not entirely sure how helpful it is.’

Lieserl glanced up at the maintenance layer, a fifth of a mile above her, with its tangle of tree roots and plumbing conduits. ‘Look at that primitive mess up there, by contrast . . . Lethe’s waters, Milpitas, this was a starship designed to last a thousand years. Some of that design looks as if it predates the Romans.’ She sighed. ‘You know, I caught a few glimpses of human technology, as we advanced over the years after the
Northern
’s launch. Obviously, we got better with time. But we always -
always
- ended up carrying our damn plumbing with us. I don’t think humans ever, in their long history,
ever
came close to matching the simple perfection of this one Xeelee artifact, this nightfighter.’

Milpitas dipped closer to the transparent base surface and peered through it, intent. ‘Perhaps you are right. But does that imply we should bow down and worship the Xeelee and all their works?’

‘No,’ she said coldly. ‘But it
does
imply that the Xeelee were smarter than we ever were, or could have become.’

She saw his eyebrows rise, through a fraction of an inch; otherwise he didn’t reply.

Now they were close to the rim of the base, near the transparent, curving wall of the loading bay. Here, the broad shoulders of the ’fighter nestled against the underside of the base; thick bands curled from the base around the ‘fighter’s curves and out of sight, hugging the ‘fighter against the lifedome.

Milpitas leaned over the control bar of his scooter, peering at the attaching bands. He seemed quite fearless, Lieserl thought with some amusement, now that he was only a few feet above the lifedome base: close to the floor of his rigid, gravity-dominated mental universe.

She allowed herself to sail smoothly along the lines of the Xeelee ship.
Shoulders
- yes, that was a good label for this part of the ‘fighter, at the root of the wings; here, so close to the ship, she had a real sense of being
carried
, on the broad, strong shoulders of some giant of construction material.

Milpitas straightened up from his inspection.

‘So how’s the engineering?’ she asked.

‘Fine,’ he said, without looking up. ‘That is, within tolerance limits . . . The creep is minimal today.’

‘
Creep
?’

He studied her. ‘Perhaps you’re not aware of the problems we faced, fixing the lifedome to this nightfighter. Lieserl, Xeelee construction material is effectively frictionless, and it is harder than any material substance known to us. It’s impervious even to exotic matter . . . You know we’ve speculated its manufacture may have violated the Pauli Exclusion Principle—’

‘I heard about that.’

‘So when we came to attach the lifedome, we couldn’t simply
nail
a superstructure to the nightfighter. No known adhesive would adhere to the construction material either. So, instead, we constructed a loose cage around the ‘fighter.’

Governed by the
Northern
’s processors, ‘bots had drawn in the straps comprising the cage, slowly and steadily tugging the lifedome against the nightfighter.

‘So,’ the Planner said, ‘the strap arrangement hugs the nightfighter tightly against us, without
fixing
us to it. But that’s obviously enough to persuade the ‘fighter to carry the lifedome safely through hyperspace.’

‘And - creep?’

‘Because the cage is not fixed to the ‘fighter - and because we are subject to various stresses - the cage’s bands slip over the construction-material surface. They creep. But we have nanobots out there working continually, readjusting the straps and compensating for stress.’

Lieserl nodded. ‘It’s a smart solution, Milpitas.’

He bowed, sardonically. ‘Perhaps. But I can’t take the credit for it. I merely implemented the design which—’

Suddenly she felt a stab of pity for this scarred,
stunted
man. ‘Don’t underestimate yourself,’ she said on impulse. ‘Believe me, you’ve achieved so much . . .’

‘For a madman?’ he asked disarmingly. He smiled at her. ‘I know you think I’m a rather foolish, rigid person, Lieserl.’

Startled, she opened her mouth to deny this, but he held up his hand.

‘Well, perhaps I am. But I
was
responsible, in large part, for the teams of ‘bots which constructed this frame for the nightfighter. I know that our sensors could tell us much more about the state of the infrastructure which fixes us to this nightfighter than my naked gaze ever could. And yet—’

‘And yet, you feel you want to see it for yourself?’ She smiled. ‘You’re wrong, Planner. You’re not the easiest person I’ve ever had to get along with, but I don’t think you’re a fool to follow your instincts.’

He studied her, coolly appraising. ‘You believe so?’

‘I know so,’ she said firmly. ‘After all, that was the whole point of my stay in the Sun - in fact, the point of my very
existence
. Plenty of probes were dropped into the Sun ahead of me, and after me. I was sent in so that - at least through a surrogate - human eyes could
see
what was happening in there.’

He grunted. ‘Although, it seems, we made precious little use of the insights you gained.’

‘That’s as may be.’ She laughed. ‘But I couldn’t control that.’

He studied her. ‘You may be a surrogate,’ he said. ‘But, Lieserl, despite that, your humanity is powerful and obvious.’

That left her confused. She kept her face straight, determinedly. She issued subvocal commands, overriding the autonomic simulation of her face; she was adamant that her cheeks shouldn’t show a hint of colouring. ‘Thank you,’ she said lightly. ‘Although I’m not sure you
need
thanks. You’re not proffering compliments, are you? I suspect you don’t praise, Planner; you
ap
praise,’ she said.

‘Perhaps.’ He turned away, closing the subject.

She studied his battered profile. Milpitas gave the impression of a man in control, but maybe he gave away more than he bargained for. With Milpitas, the communication of information was only one function - and a subsidiary one at that - of speech. The real purpose of conversation, for Milpitas, was
control
. She felt he was constantly fencing with her - testing her sharpness, and strength of will.

This was a man who was used to power, and used to exerting it, even in the most trivial conversation. But what type of person was this who - after centuries of subjective existence - would bother to fence with a tired old Virtual like her?