Ve was sitting on the edge of a deep canyon, watching leaf-green dust clouds flow in around ver like a vivid but ethereal waterfall, when Gabriel appeared. Blanca had spent some time worrying about the problems with the Forge, but within the first megatau it had slipped from vis thoughts completely. Ve knew they'd sort it out, the way they'd sorted out every other obstacle. It was always just a matter of perseverance.
Gabriel said calmly, 'Gamma rays are coming through the far end now.'
'That's wonderful! What was the problem? A misaligned laser?'
'There was no problem. We haven't carried out any repairs. We haven't changed a thing.'
'What, the mouth just drifted back into the focus? Is it oscillating back and forth in the trap?'
Gabriel dipped his hands into the green flow. He was always sitting at the Locus, perfectly positioned. 'The gamma rays we're seeing now are the ones that went in at the start. We coded all the pulses with a time stamp, remember? Well, the first pulses to emerge had the time stamp for the gamma rays sent in five and a half days ago. They've taken as long to come out as if they'd crossed the ordinary space between the mouths. Exactly, down to the picosecond. The wormhole is traversable, but it isn't a short cut. It's a hundred and forty billion kilometers long.'
Blanca absorbed this in silence. Asking if he was sure didn't seem like a good idea; the Forge group would have spent the last few megatau searching frantically for a more palatable conclusion.
Finally, ve said, 'Why? Do you have any ideas?'
He shrugged. 'The only thing we can come up with that makes any sense is this: the total energy of the wormhole depends almost entirely on the size and shape of the mouths. It's the mouths that interact with virtual gravitons; the wormhole tunnel can be as long or short as you like, and the mouths will still have exactly the same mass.'
'Yes, but that's no reason for the tunnel to grow longer, just because the mouths are moved apart in external space.'
'Wait. There's a tiny correction to the total energy that does depend on length. If the wormhole is shorter than the path through external space, then the energy of the virtual particles passing through it will be slightly higher than the normal vacuum energy. So if the wormhole is free to adjust its length to minimize that energy, the internal distance between the mouths will end up the same as the external distance.'
'But the wormhole isn't free to do that! Kozuch Theory won't allow it to grow longer than ten-to-the-minus- thirty-five meters; in the six extra dimensions, the whole universe is no wider than that!'
Gabriel said dryly, 'It seems Kozuch Theory has a few problems. First Lacerta, still unexplained. Now this.' The gleisners had put a non-sentient probe into orbit around the Lacerta black hole, but it had revealed nothing about the cause of the neutron stars' collision.
They sat in silence for a while, legs hanging over the canyon's edge, watching the green mist cascading down. In terms of a pure intellectual challenge, Gabriel couldn't have hoped for more: Kozuch Theory would have to be completely re-assessed, or even replaced, and the instrument he'd spent the last eight hundred years helping to build would be at the center of the transformation.
It was only as a short cut to the stars that the Forge had turned out to be a complete waste of time.
Blanca said, 'You've brought us closer to the truth. That's never a defeat.'
Gabriel laughed bitterly. 'No? There's already talk of cloning a thousand copies of Carter-Zimmerman and dispatching them all in different directions, to help us catch up with the gleisners. If the wormholes had been instantly traversable they would have bound the whole galaxy together; we could have moved from star to star as easily as we jump from scape to scape. But now we're destined for fragmentation. A few clones of C-Z will fly off to the stars, centuries will pass… and by the time any news comes back the other polises will be past caring. We'll all drift apart.' He scooped a handful of dust forward, speeding its fall over the precipice. 'I was going to build a network spanning the universe. That's who I was: the citizen who'd put it all in the palms of our hands. Who am I now?'
'Instigator of the next scientific revolution.'
'No.' He shook his head slowly. 'I can't turn that corner. I can live with failure. I can live with humiliation. I can meekly follow the gleisners into space, slower than light, accepting that there's no better way after all. But don't expect me to take the thing that's poisoned my dreams and embrace it as some kind of triumphant revelation.'
Blanca watched him staring morosely into the distance. Ve'd been wrong, for all these centuries: the elegance of Kozuch Theory had never been enough for Gabriel. So the chance to uncover and remove its flaws was no consolation to him at all.
Blanca stood. 'Come on.'
'What?'
Ve reached down and took his hand. 'Jump with me.'
'Where?'
'Not to another scape. Here. Over the edge.'
Gabriel regarded ver dubiously, but he rose to his feet. 'Why?'
'It will make you feel better.'
'I doubt it.'
'Then do it for me.'
He smiled ruefully. 'All right.'
They stood on the edge of the rock, feeling the dust swirl down around their feet. Gabriel said, surprised, 'It makes me uneasy, just knowing that I'm going to give tip control of my icon. Must be something vestigial. You know even winged exuberants had a strong reaction against free fall? Diving was often a useful maneuver for them, but they retained an instinctive desire to put an end to it as soon as possible.'
'Well, don't panic and fly off, or I'll never forgive you. Ready?'
'No.' Gabriel craned his neck forward. 'I really don't like this.'
Blanca squeezed his hand and stepped forward, and the laws of the imaginary world sent them tumbling down.
9
DEGREES OF FREEDOM
Carter-Zimmerman polis, interstellar space
58 315 855 965 866 CST
21 March 4082, 8:06:03.020 UT
Blanca felt obliged to visit the Hull at least once a year. Everyone in Carter-Zimmerman knew that ve'd chosen to experience some subjective time on the trip to Fomalhaut—despite Gabriel's decision to remain frozen for the duration—and there was really only one acceptable reason for doing that.
'Blanca! You're awake!' Enif had spotted ver already, and he bounded toward ver on all fours across the micrometeorite-pitted ceramic, sure-footed as ever. Alnath and Merak followed, at a slightly more prudent velocity. Most of the Osvalds used embodiment software to simulate hypothetical vacuum-adapted fleshers, complete with airtight, thermally insulating hides, infrared communication, variably adhesive palms and soles, and simulated repair of simulated radiation damage. The design was perfectly functional, but since each space-going clone of Carter-Zimmerman polis was barely larger than one of these Star Puppies, having the real things as passengers was out of the question. The Hull was just a plausible fiction, a synthetic scape melding the real sky with an imaginary spacecraft hundreds of meters long; thousands of times heavier than the polis, it could only have been real if they'd postponed the Diaspora for a few millennia in order to manufacture enough antihydrogen to fuel it.
Enif almost collided with ver, but he swerved aside just in time, barely maintaining his grip. He was always
