Paolo added wryly, 'And how long we took to see past the distractions.'
'No one's perfect.' Yatima hesitated. 'I was in on the technical side more than you, but I'll still need you to help piece things together.'
'Why?' Paolo swung restlessly around the girder he was holding.
'Are we going to tell them what happened on Poincare?'
'Of course.'
'Then they'll need to know more about Orlando.'
12
HEAVY
Carter-Zimmerman polis, interstellar space
85 274 532 121 904 CST
4 July 4936, 1:15:19.058 UT
Orlando Venetti woke for the twelfth time in nine centuries, clear-headed and hopeful, fully expecting to find that Voltaire C-Z had reached its destination. The previous wake-up calls had all been triggered by bulletins from other clones of the polis, but this time he'd fallen asleep knowing that no more arrivals were due before their own. It was Voltaire's turn to make news—even if that simply meant adding one more set of barren worlds to the catalogue of post-Orphean anticlimaxes.
He rolled over and checked the bedside clock, its glowing symbols disembodied in the blackness of the cabin. It was seventeen years before arrival. Someone on another C-Z must have made a belated discovery, important enough for his exoself to wake him. Orlando felt cheated; he'd run out of enthusiasm for the revelations of the other polises, light years away and decades ago.
He lay swearing for a while, then memories of a dream began to surface. Liana and Paolo had been arguing with him in the house in Atlanta, both trying to convince him that Paolo was her son. Liana had even shown him images of the birth. When Orlando had tried to explain about psychogenesis, Paolo had smirked and said, 'Try doing that in a test tube!' Orlando had realized then that he had no choice: he was going to have to tell them about Lacerta. And though he'd been imagining that Paolo would escape unharmed, he could see now that this was impossible. Paolo was flesh, too. The robots would find three blackened corpses in the ruins.
Orlando closed his eyes and waited for the pain to recede. He'd told Paolo that he'd be staying frozen en route, utterly inert; he hadn't admitted to anyone that he'd chosen to dream instead. A wise omission, given Fomalhaut. That slumbering clone would have formally diverged into a separate individual; random noise in the embodiment software guaranteed that, even without different sensory inputs. But Orlando didn't think of it as a death; even his waking Earth-self's suicide didn't amount to that. He'd always intended to merge with every willing clone at the end of the Diaspora, and the loss of one or two of them along the way seemed no more tragic than losing his memories of one or two days in every thousand.
He left the cabin and walked barefoot through the cool grass to the edge of the flying island. The scape was dark as any moonless night on Earth, but the ground was even and the route familiar. He had gladly rid himself of the tedious business of defecation, but he was no more willing to give up the pleasure of emptying his bladder than he was willing to give up the possibility of sex. Both acts were entirely arbitrary, now that they were divorced from any biological imperative, but that only brought them closer to other meaningless pleasures, like music. If Beethoven deserved to endure, so did urination. He manipulated the stream into Lissajous figures as it vanished into the starry blackness beneath the jutting rock.
He'd forced only a little of his own nature onto Paolo—like any good bridger, just enough to let the two of them understand each other—and he'd gladly see subsequent generations embrace all the possibilities of software existence. But redesigning himself in an attempt to do the same in person would have been nothing but self- mutilation. That was why he dreamt the old way: confused, unconvincing, uncontrollable dreams, not the lucid, detailed, wish-fulfillment fantasies or cloyingly therapeutic psychodramas of the assimilated. His faithfully mammalian dreams would never bring Liana back; nor would they drag him down some tortuous path of allegory and catharsis designed to reconcile him to her loss. They revealed nothing, meant nothing, changed nothing. But to excise or disfigure them would have been like taking a knife to his flesh.
Voltaire lay low in the sky, in the direction Orlando thought of as east. It was a dim reddish speck at this distance, about as bright as Mercury seen from Earth, an ancient K5 star only one sixth as luminous as the sun. Five terrestrial planets, and five gas giants more in Neptune's league than Jupiter's, had been observed or inferred long before the Diaspora's launch, but individual spectra for the inner planets had continued to elude both the colossal instruments back home and the extremely modest equipment carried by the polis itself.
'What are you offering? Sanctuary?' He gazed at the star. Not likely. Just a few more barren planets. A few more lessons in the fragility of life, and the indifference of the forces that created and destroyed it.
Back in the cabin, Orlando considered ignoring the call and going straight hack to sleep. It would either be bad news—another Fomalhaut, or worse, or evidence of life so subtle that it had taken a century or two of exploration to uncover. Maybe one of the moons of one of the gas giants orbiting 51 Pegasus had yielded a few fossilized microbes in some previously uncharted crevice. Evidence of a third biosphere would be hugely significant, but he was tired of poring over the details of distant worlds in the pre-dawn darkness.
Then again, maybe the Orphean squid had finally gained an inkling of the nature of their floating universes. Orlando laughed wearily. He was jealous, but he was hooked; the chance of a development in squid culture was enough to puncture his indifference.
He clapped his hands, and the cabin fit up. He sat on his bed and addressed the wall screen. 'Report.' Text appeared, summarizing his exoself's reasons for waking him. Orlando could not abide non-sentient software that talked back.
The news was local, though the chain of events behind it had started hack on Earth. Someone in Earth C-Z had designed an improved miniature spectroscope, which could he constructed by nanoware modifications to the existing polis-borne model. The local astronomy software had taken it upon itself to do just that, and thanks to the new instrument the atmospheric chemistry of Voltaire's ten planets had now been determined.
The first surprise was that the innermost planet, Swift, possessed an atmosphere rather different than expected: mostly carbon dioxide and nitrogen, at a fifth the total pressure of Earth's, but there were also significant traces of hydrogen sulphide and water vapor. With only 60 percent of Earth's gravity, and a surface temperature averaging 70 degrees Celsius, virtually all of Swift's water should have been lost in the twelve billion years since its formation—broken down by UV into hydrogen and oxygen, with the hydrogen escaping into space.
The second surprise was that the hydrogen sulphide appeared not to be in thermodynamic equilibrium with the rest of the atmosphere. It was either being outgassed from the planet's interior—unlikely, after twelve billion years—or it was a by-product of some form of non-equilibrium chemical process driven by the light from Voltaire. Quite possibly life.
But the third surprise set Orlando's skin tingling, outweighing any drab visions of boiling lakes full of malodorous bacteria. The spectra also showed that the molecules in Swift's atmosphere contained no ordinary hydrogen, no carbon-12, no nitrogen-14, no oxygen-16, no sulfur-32. Not a trace of the most cosmically abundant isotopes, though they were present in the normal proportions on Voltaire's nine other planets. On Swift, there was only deuterium, carbon-13, nitrogen-15, oxygen-18, sulfur-34: the heaviest stable isotope of each element.
That explained why water vapor was still present, these heavier molecules would stay closer to the surface of the planet, and when they were split the deuterium would have more of a chance to stick around and recombine. But not even the preferential loss of lighter isotopes could explain these impossibly skewed abundances; Swift's atmosphere contained hundreds of thousands of times more deuterium than it should have possessed when the planet was formed. The software was noncommittal about the implications, but Orlando had
