The Year's Best SF 22 # 2004

by Gardner Dozois (ed)

  I turned briefly to look at Ajit. For Kane, he didn’t even exist.

  6. PROBE

  “The probe has moved,” I said to Ajit and Kane. “It’s way beyond the calculated drift. By a factor of ten.”

  Kane’s eyes, red with work, nonetheless sharpened. “Let me see the trajectory.”

  “I transferred it to both your terminals.” Ordinarily ship’s data is kept separate, for my eyes only.

  Kane brought up the display and whistled.

  The probe is under the stresses, gravitational and radiational, that will eventually destroy it. We all know that. Our fleshy counterparts weren’t even sure the probe would survive to send one minicap of data, and I’m sure they were jubilant when we did. Probably they treated the minicap like a holy gift, and I can easily imagine how eager they are for more. Back on the ship, I—the other “I”—had been counting on data, like oil, to grease the frictions and tensions between Ajit and Kane. I hoped it had.

  We uploads had fuel enough to move the probe twice. After that, and since our last move will be no more than one-fiftieth of a light-year from the black hole at the galactic core, the probe will eventually spiral down into Sag A*. Before that, however, it will have been ripped apart by the immense tidal forces of the hole. However, long before that final death plunge, we analogues will be gone.

  The probe’s current drift, however, considerably farther away from the hole, was nonetheless much faster than projected. It was also slightly off course. We were being pulled in the general direction of Sag A*, but not on the gravitational trajectory that would bring us into its orbit at the time and place the computer had calculated. In fact, at our current rate of acceleration, there was a chance we’d miss the event horizon completely.

  What was going on?

  Kane said, “Maybe we better hold off moving the probe to the other side of Sag A West until we find out what’s pulling us.”

  Ajit was studying the data over Kane’s shoulder. He said hesitantly, “No … wait … I think we should move.”

  “Why?” Kane challenged.

  “I don’t know. I just have … call it an intuition. We should move now.”

  I held my breath. The only intuition Kane usually acknowledged was his own. But earlier things had subtly shifted. Kane had said, “Ajit’s right. That region is the source of whatever pull is distorting the gas infall.” Ajit had not changed expression, but I’d felt his pleasure, real as heat. That had given him the courage to now offer this unformed—“hairbaked” was Kane’s usual term—intuition.

  Kane said thoughtfully, “Maybe you’re right. Maybe the—” Suddenly his eyes widened. “Oh my god.”

  “What?” I said, despite myself. “What?”

  Kane ignored me. “Ajit—run the sims for the gas orbits in correlation with the probe drift. I’ll do the young stars!”

  “Why do—” Ajit began, and then he saw whatever had seized Kane’s mind. Ajit said something in Hindi; it might have been a curse, or a prayer. I didn’t know. Nor did I know anything about their idea, or about what was happening with the gas orbits and young stars outside the probe. However, I could see clearly what was happening within.

  Ajit and Kane fell into frenzied work. They threw comments and orders to each other, transferred data, backed up sims and equation runs. They tilted their chairs toward each other and spouted incomprehensible jargon. Once Kane cried, “We need more data!” and Ajit laughed, freely and easily, then immediately plunged back into whatever he was doing. I watched them for a long time, then stole quietly up to the observation deck for a minute alone.

  The show outside was more spectacular than ever, perhaps because we’d been pulled closer to it than planned. Clouds of whirling gases wrapped and oddly softened that heart of darkness, Sag A*. The fiery tail of the giant red star lit up that part of the sky. Stars glowed in a profusion unimaginable on my native Station J, stuck off in a remote arm of the galaxy. Directly in front of me glowed the glorious blue stars of the cluster IRS16.

  I must have stayed on the observation deck longer than I’d planned, because Kane came looking for me. “Tirzah! Come on down! We want to show you where we’re moving and why!”

  We.

  I said severely, gladness bursting in my heart, “You don’t show me where we’re going, Kane, you ask me. I captain this ship.”

  “Yeah, yeah, I know, you’re a dragon lady. Come on!” He grabbed my hand and pulled me toward the ladder.

  They both explained it, interrupting each other, fiercely correcting each other, having a wonderful time. I concentrated as hard as I could, trying to cut through the technicalities they couldn’t do without, any more than they could do without air. Eventually I thought I glimpsed the core of their excitement.

  “Shadow matter,” I said, tasting the words on my tongue. It sounded too bizarre to take seriously, but Kane was insistent.

  “The theory’s been around for centuries, but deGroot pretty much discredited it in 2086,” Kane said. “He—”

  “If it’s been discredited, then why—” I began.

  “I said ‘pretty much,’” Kane said. “There were always some mathematical anomalies with deGroot’s work. And we can see now where he was wrong. He—”

  Kane and Ajit started to explain why deGroot was wrong, but I interrupted. “No, don’t digress so much! Let me just tell you what I think I understood from what you said.”

  I was silent a moment, gathering words. Both men waited impatiently, Kane running his hand through his hair, Ajit smiling widely. I said, “You said there’s a theory that just after the Big Bang, gravity somehow decoupled from the other forces in the universe, just as matter decoupled from radiation. At the same time, you scientists have known for two centuries that there doesn’t seem to be enough matter in the universe to make all your equations work. So scientists posited a lot of ‘dark matter’ and a lot of black holes, but none of the figures added up right anyway.

  “And right now, neither do the orbits of the infalling gas, or the probe’s drift, or the fact that massive young stars were forming that close to the black hole without being ripped apart by tidal forces. The forces acting on the huge clouds that have to condense to form stars that big.”

  I took a breath, quick enough so that neither had time to break in and distract me with technicalities.

  “But now you think that if gravity did decouple right after the Big Bang—”

  “About 10-43 seconds after,” Ajit said helpfully. I ignored him.

  “—then two types of matter were created, normal matter and ‘shadow matter.’ It’s sort of like matter and antimatter, only normal matter and shadow matter can’t interact except by gravity. No interaction through any other force, not radiation or strong or weak forces. Only gravity. That’s the only effect shadow matter has on our universe. Gravity.

  “And a big chunk of this stuff is there on the other side of Sag A West. It’s exerting enough gravity to affect the path of the infalling gas. And to affect the probe’s drift. And even to affect the young stars because the shadow matter-thing’s exerting a counterpull on the massive star clouds, and that’s keeping them from being ripped apart by the hole as soon as they otherwise would be. So they have time to collapse into young stars.”

  “Well, that’s sort of it, but you’ve left out some things that alter and validate the whole,” Kane said impatiently, scowling.

  “Yes, Tirzah, dear heart, you don’t see the—you can’t just say that ‘counterpull’—let me try once more.”

  They were off again, but this time I didn’t listen. So maybe I hadn’t seen the theory whole, but only glimpsed its shadow. It was enough.

  They had a viable theory. I had a viable expedition, with a goal, and cooperatively productive scientists, and a probability of success.

  It was enough.

  Kane and Ajit prepared the second minicap for the big ship, and I prepared to move the probe. Our mood was jubilant. There was much laughing and joking, interrupted by i
ntense bursts of incomprehensible jabbering between Ajit and Kane.

  But before I finished my programming, Ajit’s head disappeared.

  7. SHIP

  Kane worked all day on his shadow-matter theory. He worked ferociously, hunched over his terminal like a hungry dog with a particularly meaty bone, barely glancing up and saying little. Ajit worked, too, but the quality of his working was different. The terminals both connect to the same computer, of course; whatever Kane had, Ajit had, too. Ajit could follow whatever Kane did.

  But that’s what Ajit was doing: following. I could tell it from the timing of his accesses, from the whole set of his body. He was a decent scientist, but he was not Kane. Given the data and enough time, Ajit might have been able to go where Kane raced ahead now. Maybe. Or, he might have been able to make valuable additions to Kane’s thinking. But Kane gave him no time; Kane was always there first, and he asked no help. He had shut Ajit out completely. For Kane, nothing existed right now but his work.

  Toward evening he looked up abruptly and said to me, “They’ll move the probe. The uploads—they’ll move it.”

  I said, “How do you know? It’s not time yet, according to the schedule.”

  “No. But they’ll move it. If I figured out the shadow matter here, I will there, too. I’ll decide that more data is needed from the other side of Sag A West, where the main shadow mass is.”

  I looked at him. He looked demented, like some sort of Roman warrior who has just wrestled with a lion. All that was missing was the blood. Wild, filthy hair—when had he last showered? Clothes spotted with the food I’d made him gulp down at noon. Age lines beginning, under strain and fatigue and despite the rejuve, to drag down the muscles of his face. And his eyes shining like Sag A West itself.

  God, I loved him.

  I said, with careful emphasis, “You’re right. The Tirzah upload will move the ship for better measurements.”

  “Then we’ll get more data in a few days,” Ajit said. “But the radiation on the other side of Sag A West is still intense. We must hope nothing gets damaged in the probe programs, or in the uploads themselves, before we get the new data.”

  “We better hope nothing gets damaged long before that in my upload,” Kane said, “or they won’t even know what data to collect.” He turned back to his screen.

  The brutal words hung in the air.

  I saw Ajit turn his face away from me. Then he rose and walked into the galley.

  If I followed him too soon, he would see it as pity. His shame would mount even more.

  “Kane,” I said in a low, furious voice, “you are despicable.”

  He turned to me in genuine surprise. “What?”

  “You know what.” But he didn’t. Kane wasn’t even conscious of what he’d said. To him, it was a simple, evident truth. Without the Kane upload, no one on the probe would know how to do first-class science.

  “I want to see you upstairs on the observation deck,” I said to him. “Not now, but in ten minutes. And you announce that you want me to see something up there.” The time lag, plus Kane’s suggesting the trip, would keep Ajit from knowing I was protecting him.

  But now I had put up Kane’s back. He was tired, he was stressed, he was inevitably coming down from the unsustainable high of his discovery. Neither body nor mind can keep at that near-hysterical pitch for too long. I had misjudged, out of my own anger at him.

  He snapped, “I’ll see you on the observation deck when I want to see you there, and not otherwise. Don’t push me around, Tirzah. Not even as captain.” He turned back to his display.

  Ajit emerged from the galley with three glasses on a tray. “A celebratory drink. A major discovery deserves that. At a minimum.”

  Relief was so intense I nearly showed it on my face. It was all right. I had misread Ajit, underestimated him. He ranked the magnitude of Kane’s discovery higher than his own lack of participation in it, after all. Ajit was, first, a scientist.

  He handed a glass to me, one to Kane, one for himself, Kane took a hasty, perfunctory gulp and returned to his display. But I cradled mine, smiling at Ajit, trying with warmth to convey the admiration I felt for his rising above the personal.

  “Where did you get the wine? It wasn’t on the ship manifest!”

  “It was in my personal allotment,” Ajit said, smiling.

  Personal allotments are not listed nor examined. A bottle of wine, the statue of Shiva … Ajit had brought some interesting choices for a galactic core. I sipped the red liquid. It tasted different from the Terran or Martian wines I had grown up with: rougher, more full-bodied, not as sweet.

  “Wonderful, Ajit.”

  “I thought you would like it. It is made in my native New Bombay, from genemod grapes brought from Terra.”

  He didn’t go back to his terminal. For the next half hour, he entertained me with stories of New Bombay. He was a good storyteller, sharp and funny. Kane worked steadily, ignoring us. The ten-minute deadline I had set for him to call me up to the observation deck came and went.

  After half an hour, Kane stood and staggered. Once before, when he’d broken Ajit’s statue, stiffness after long sitting had made Kane unsteady. That time he’d caught himself after simply bumping the wardroom table. This time he crashed heavily to the floor.

  “Kane!”

  “Nothing, nothing … don’t make a fuss, Tirzah! You just won’t leave me alone!”

  This was so unfair that I wanted to slap him. I didn’t. Kane rose by himself, shook his head like some great beast, and said, “I’m just exhausted. I’m going to bed.”

  I didn’t try to stop him from going to his bunk. I had planned on sleeping with Ajit, anyway. It seemed that some slight false note had crept into his storytelling in the last five minutes, some forced exaggeration.

  But he smiled at me, and I decided I’d been wrong. I was very tired, too. All at once I wished I could sleep alone this night.

  But I couldn’t. Ajit, no matter how well he’d recovered from Kane’s unconscious brutality, nonetheless had to feel bruised at some level. It was my job to find out where, and how much, and to set it to rights. It was my job to keep the expedition as productive as possible, to counteract Kane’s dismissing and belittling behavior toward Ajit. It was my job.

  I smiled back at him.

  8. PROBE

  When Ajit’s head disappeared, no one panicked. We’d expected this, of course; in fact, we’d expected it sooner. The probe drifted in a sea of the most intense radiation in the galaxy, much of it at lethal wavelengths: gamma rays from Sagittarius East, X-rays, powerful winds of ionized particles, things I couldn’t name. That the probe’s shielding had held this long was a minor miracle. It couldn’t hold forever. Some particle or particles had penetrated it and reached the computer, contaminating a piece of the upload-maintenance program.

  It was a minor glitch. The backup kicked in a moment later and Ajit’s head reappeared. But we all knew this was only the beginning. It would happen again, and again, and eventually programming would be hit that couldn’t be restored by automatic backup, because the backup would go, too, in a large enough hit—or because uploads are not like other computer programs. We are more than that, and less. An upload has backups to maintain the shadows we see of each other and the ship, the shadows that keep our captured minds sane. But an upload cannot house backups of itself. Even one copy smudges too much, and the copy contaminates the original. It has been tried, with painful results.

  Moreover, we uploads run only partly on the main computer. An upload is neither a biological entity nor a long stream of code, but something more than both. Some of the substratum, the hardware, is wired like actual neurons, although constructed of sturdier stuff: thousands of miles of nano-constructed organic polymers. This is why analogues think at the rate of the human brain, not the much faster rate of computers. It’s also why we feel as our originals do.

  After Ajit’s maintenance glitch our mood, which had been exuberant, sobered. But it didn�
��t sour. We worked steadily, with focus and hope, deciding where exactly to position the probe and then entering the coordinates for the jump.

  “See you soon,” we said to each other. I kissed both Kane and Ajit lightly on the lips. Then we all shut down and the probe jumped.

  Days later, we emerged on the other side of Sag A West, all three of us still intact. If it were in my nature, I would have said a prayer of thanksgiving. Instead I said to Ajit, “Still have a head, I see.”

  “And a good thing he does,” Kane said absently, already plunging for the chair in front of his terminal. “We’ll need it. And—Ajit, the mass detectors … great shitting gods!”

  It seems we were to have thanksgiving after all, if only perversely. I said, “What is it? What’s there?” The displays showed nothing at all.

  “Nothing at all,” Ajit said. “And everything.”

  “Speak English!”

  Ajit—I doubt Kane had even heard me, in his absorption—said, “The mass detectors are showing a huge mass less than a quarter light-year away. The radiation detectors—all of them—are showing nothing at all. We’re—”

  “We’re accelerating fast.” I studied ship’s data; the rate of acceleration made me blink. “We’re going to hit whatever it is. Not soon, but the tidal forces—”

  The probe was small, but the tidal forces of something this big would still rip it apart when it got close enough.

  Something this big. But there was, to all other sensors, nothing there.

  Nothing but shadows.

  A strange sensation ran over me. Not fear, but something more complicated, much more eerie.

  My voice sounded strange in my ears. “What if we hit it? I know you said radiation of all types will go right through shadow matter just as if it isn’t there”—because it isn’t, not in our universe—“but what about the probe? What if we hit it before we take the final event-horizon measurements on Sag A*?”