Vacuum Diagrams

by Stephen Baxter

  "It was the first time," Eve said, "that the name 'Xeelee' entered human discourse."

  I shuddered.

  The Xeelee Flower

  A.D. 4922

  I STILL GET TOURISTS OUT HERE, you know. Even though it's been so long since I was a hero. But then, I'm told, these days the reopened Poole wormholes will get you from Earth to Miranda in hours.

  Hours. What a miracle. Not that these tourist types appreciate it. Don't get me wrong, I don't mind the company. It just bugs me that every last one, after he's finished looking over my villa built into the five-mile cliffs of Miranda, turns his face up to the ghostly blue depths of Uranus, and asks the same dumb question:

  "Say, buddy, how come you use a fish tank for a toilet?"

  But I'm a good host, and I merely smile and snap my fingers. After a while, my battered old buttlebot limps in with a bottle of valley bottom wine, and I settle back and begin:

  "Well, my friend, I use the fish tank for a toilet for the same reason you would. Because my boss used to live in it."

  And that's how I got where I am today.

  By working for a bunch of fish, I mean, not pissing in the tank. Although I don't know what stopped me from doing just that by the time we reached Goober's Star eight months out from Earth.

  "The resolution, Jones, the resolution!" The shoal of Squeem darted anxiously around their tank, griping at me from the translator box taped to one glass wall.

  I put down the spare tank I'd been busy scraping out, and blinked across the cluttered little cabin. The buttlebot — yes, the same one, squeaky-clean in those days — scuttled past, humming happily in its chores. I picked my way to the control panel. I got out my adjustable spanner and gingerly tweaked the fiddly little enhancement vernier. Like most Xeelee-based technology it was too fine for human fingers. The secretive Xeelee evidently have great brains but tiny hands. Then again, some people haven't managed to evolve hands at all, I reflected, as the Squeem flipped around in their greenish murk.

  "Ah," enthused the Squeem as the monitors sharpened up. "Our timing is perfect."

  I gloomily considered a myriad beautiful images of two things I didn't want much to be close to: Goober's Star — about G-type, about two Earth orbits away, and about to nova; and a planet full of nervous Xeelee.

  And the most remarkable feature of the whole situation was that we weren't running for our lives. In fact, we were going to get closer — a lot closer — drawn mothlike by the greed of the Squeem for stolen Xeelee treasure.

  The buttlebot squeezed past my leg, extended a few pseudopodia, and began pushing buttons with depressing enthusiasm. I sighed and turned back to my fish tank. At least I had one up on the 'bot, I reflected; at least I was getting paid. Although, like most of the rest of humanity at that time, I hadn't exactly had a free choice in the nature of my employment—

  The Squeem's rasp broke into my thoughts. "Jones, our planet-fall is imminent. Please prepare the flitter for your descent."

  Your descent. Had they said "your" descent? I nearly dropped the fish tank.

  Carefully, I got up from my knees. "Into Lethe's waters with that." I defiantly straightened my rubber gloves. "No way. The Xeelee wouldn't let me past the orbit of the moons—"

  "The Xeelee will be fully occupied with their flight from the imminent nova. And your descent will be timed to minimize your risk."

  "That's a lot of 'you' and 'your,' " I observed witheringly. "Show me where my contract says I've got to do this."

  Can fish be said to be dry? The Squeem said drily, "That will be difficult as you haven't got a contract at all."

  They had a point. I reluctantly took off my pinafore and began to tug at the fingers of my rubber gloves. The buttlebot smugly opened up the suit locker. "You ought to send that little tin cretin," I said; and the Squeem replied, "We are."

  I swear to this day that buttlebot jumped.

  And so the buttlebot and I found ourselves drifting through a low orbit over the spectacular Xeelee landscape. We watched morosely as the main ship pulled away from the tiny, human-design flitter, and wafted our employer off to the comparative safety of the far-side of one of the planet's two moons.

  My work for the Squeem, roughly speaking, was to do any fiddly, dirty, dangerous jobs the buttlebot wasn't equipped for, such as to clean out fish tanks and land on hostile alien planets. And me, a college graduate. Of course, the role of humanity at that time was roughly equivalent.

  It isn't that the Squeem — or any of the other races out there — were any brighter than we were or better or even much older. But they had something we didn't, and had — then — no way of getting our hands on.

  And that was stolen Xeelee technology. For instance the hyperdrive, scavenged by the Squeem from a derelict Xeelee ship centuries earlier, had been making that fishy race's fortune ever since. Tools and gadgets of all kinds, on which a Galactic civilization had been based. And all pilfered, over millions of years, from the Xeelee.

  I use the word civilization loosely, of course. Can it be used to describe what exists out there — a ramshackle construct based on avarice, theft and the subjugation of junior races like ourselves?

  We began our descent. The dark side of the Xeelee world grew into a diamond-studded carpet: fantastic cities glittered on the horizon. The Xeelee — so far ahead, they make the rest of us look like tree-dwellers. Secretive, xenophobic. Not truly hostile to the rest of us; merely indifferent. Get in their way and you would be rubbed aside like a mote in the eye of a god.

  And I was as close to them as any sentient being had ever got, probably. Nice thought.

  Yes, like gods. But very occasionally careless. And that was the basis of the Squeem's plan that day.

  We dropped slowly. The conversation left a lot to be desired. And the surface of the planet blew off.

  I recoiled from the sudden light at the port, and the buttlebot jerked us down through the incredible traffic. It looked as if whole cities had detached from the ground and were fleeing upwards, light as bubbles. The flitter was swept with shifting color; we were in the down elevator from Heaven.

  Abruptly as it had risen, the Xeelee fleet was past. Immense, night-dark wings spread over the doomed planet for a moment, as if in farewell; and then the fleet squirted without fuss into infinity. Evidently, we hadn't been noticed.

  The flitter moved in looser arcs now towards the surface. I took over from the buttlebot and began to seek out a likely landing place. We skimmed over a scoured landscape.

  From behind the darkened planet's twin moons, the valiant Squeem poked their collective nose. "The nova is imminent; please make haste with your planetfall."

  "Thanks. Now get back in your tin and let me concentrate." I wrestled with the flitter's awkward controls; we lurched towards the ground. I cursed the Xeelee under my breath; I thought of fish pie; I didn't even much like the buttlebot. The last thing I needed at a time like that was a reminder that what I was doing was about as clever as looting a house on fire. Get in after the owners have fled; get out before the roof caves in. The schedule was kind of tight.

  Finally, we thumped down. Reproachfully, the buttlebot uncoiled its pseudopodia from around a chair leg, let down the hatch and scuttled out. Already suited up, I grabbed a data desk and flashlight laser, and staggered after it. That descent hadn't done me a lot of good either, but in the circumstances I preferred not to hang around.

  I emerged into a bonelike landscape. The noise of my breath jarred in the complete absence of life. I imagined the planet trembling as its bloated sun prepared to burst. It wasn't a happy place to be.

  I'd put us down in the middle of a village-sized clump of buildings, evidently too small or remote to lift with the rest of the cities. In a place like this we had our best chance of coming across something overlooked by the Xeelee in their haste, some toy that could revolutionize the economies of a dozen worlds.

  Listen, I'm serious. It had happened before. Although any piece of junk that would satisfy th
e Squeem and let me get out of there would do for me.

  The low buildings gaped in the double shadows of the moonlight. The buttlebot scurried into dark places. I ran my hand over the edge of a doorway, and came away with a fine groove in a glove finger. The famous Xeelee construction material: a proton's width thick, about as dense as glass wool, and as strong as Life itself. And no one had a clue how to make or cut it. Nothing new; a familiar miracle.

  The buttlebot buzzed past excitedly, empty-handed. The vacant place was soulless; there was nothing to evoke the people who had so recently lived here. The thorough Xeelee had even evacuated their ghosts.

  "Squeem, this is a waste of time."

  "I estimate some minutes before you should ascend. Please proceed; I am monitoring the star."

  "I feel so secure knowing that." I tried a few more doorways. The flashlight laser probed emptiness. — Until, in the fourth or fifth building, I found something.

  The artifact, dropped in a corner, was a little like a flower. Six angular petals, which looked as if they were made of Xeelee sheeting, were fixed to a small cylindrical base; the whole thing was about the size of my open hand. An ornament? The readings from my data desk — physical dimensions, internal structure — didn't change as I played with the toy in the light of the flashlight laser. Half the base clicked off in my hand. Nothing exciting happened. Well, whatever it was, maybe it would make the Squeem happy and I could get out.

  I took it out into the moonlight. "Squeem, are you copying?" I held it in the laser beam, and twisted the base on or off.

  The Squeem jabbered excitedly. "Jones! Please repeat the actions performed by your opposable thumb, and observe the data desk. This may be significant."

  "Really." I clicked the base on and off, and inspected the exposed underside in the laser light. No features. But a readout trembled on the data desk; the mass was changing.

  I experimented. I took away the torch: the change in mass, a slow rise, stopped. Shine the torch, and the mass crept up. And when I replaced the base, no change with or without the torch. "Hey, Squeem," I said slowly, "are you thinking what I'm thinking?"

  "Jones, this may be a major find."

  I watched the mass of the little flower creep up in the light of the torch. It wasn't much — about an ounce per second, to be exact — but it was there. "Energy to mass, right? Direct conversion of the radiant energy of the beam." And the damn thing wasn't even warm in my hand.

  I clicked the base back into place; the flower's growth stopped. Evidently, the base was a key; remove it to make the flower work. The Squeem didn't remark on this; for some reason, I didn't point it out. Well, I wasn't asked.

  "Jones, return to the flitter at once. Take no further risks in the return of the artifact."

  That was what I wanted to hear. I ran through the skull-like town, clutching the flower. The buttlebot scurried ahead. I gasped out, "Hey, this must be what they use to manufacture their construction material. Just stick it out in the sunlight, and let it grow." Presumably the petals, as well as being the end product, were the main receptors of the radiant energy. In which case, the area growth would be exponential. The more area you grow, the more energy you receive; and the more energy you receive, the more area you grow, and...

  I thought of experiments to check this out. Listen, I had in my hand a genuine piece of Xeelee magic; it caught my imagination. Of course, the Squeem would be taking the profits. I considered ways to steal the flower...

  My feet itched; they were too close to a nova. I had other priorities at that point. I stopped thinking and ran.

  We bundled into the flitter; I let the buttlebot lift us off, and stored the Xeelee flower carefully in a locker.

  The lift was bumpy: high winds in the stratosphere. A spectacular aurora shivered over us. "Squeem, are you sure you've done your sums right?"

  "There is an inherent uncertainty in the behavior of novae," the Squeem replied reassuringly. We reached orbit; the main ship swam towards us. "After all," the Squeem lectured on, "a nova is by definition an instability. However I am confident we have at least five minutes before—"

  At once, three events.

  The moons blazed with light.

  The Squeem shut up.

  The main ship turned from a nearby cylinder into an arrow of light, pointing at the safety of the stars.

  "Five minutes? You dumb fish."

  The buttlebot worked the controls frantically, unable to comprehend the abrupt departure of the Squeem. The nova had come ahead of schedule; the twin moons reflected its sick glory. We were still over the dark side of the planet, over which screamed a wind that came straight from the furnaces of a medieval hell. On the day side, half the atmosphere must already have been blasted away.

  The flitter was a flimsy toy. I estimated we had about ten minutes to sunrise.

  My recollection of the first five of those minutes is not clear. I do not pretend to be a strong man. I remember an image of the walls of the flitter peeling back like burnt flesh, the soft interior scoured out...

  Leaving one object, one remnant, spinning in a cloud of metal droplets.

  I realized I had an idea.

  I grabbed the Xeelee flower from its locker, and wasted a few more seconds staring at it. The only substance within a million miles capable — maybe — of resisting the nova, and it was the size of my palm. I had to grow it, and fast. But how?

  My brain chugged on. Right. One way. But would there be time? The flower's activating base came off, and went into a suit pocket.

  The buttlebot was still at the controls, trying to complete its rendezvous with a vanished ship. If there'd been time, I might have found this touching; as things were, I knocked it aside and began entering an emergency sequence. My thinking was fuzzy, my gloved fingers clumsy, and it took three tries to get it right. You can imagine the effect on my composure.

  Now I had about a minute to get to the back of the vessel. I snapped closed my visor and de-cycled the airlock. I failed to observe the mandatory safety routines, thus voiding the manufacturer's guarantees. The buttlebot clucked nervously about the cabin.

  Clutching the Xeelee flower, I pulled into space and set off one-handed.

  I couldn't help looking down at the stricken planet. Around the curve of the world, the air rushing from the day side was gathering into a cyclone to end all cyclones; clouds swarmed like maggots, fleeing the boiling oceans. A vicious light spread over the horizon.

  Followed by the confused buttlebot, I made it to the reactor dump hatch. In about thirty seconds, the safety procedure I had set up should funnel all the flitter's residual fusion energy out through the hatch into space, in one mighty squirt. Except, the energy pulse wasn't going to reach free space; it would all hit the Xeelee flower, which I was going to fix into place over the hatch.

  Right. Fix it. With what? I fumbled in my suit pockets for tape. A piece of string. Chewing gum. My mind emptied. The buttlebot scuttled past, intent on some vital task.

  I grabbed it, and wrapped the flower in one of its pseudopodia. "Listen," I screamed at it, "stay right here. Got it? Hold it for five seconds, please, that's all I ask."

  No more time. I scrambled to the far side of the flitter.

  Five seconds isn't long. But that five seconds was long enough for me to notice the brightening of the encroaching horizon. Long enough to note that I was gambling my life on a few more or less unfounded assumptions about the Xeelee flower.

  It had to be a hundred percent efficient; if it couldn't absorb all that was about to be thrown at it, then it would evaporate like dew. It had to grow exponentially, with the rate of growth area increasing with the area grown already. Otherwise it couldn't grow fast enough to save me as planned.

  I also had plenty of time to wonder if the buttlebot had got bored—

  There was a flash. I peered around the flitter's flank.

  It had worked. The flower had blossomed in the fusion light into an umbrella-sized dish, maybe just big enough for th
e hard rain that was going to fall.

  The flower tumbled slowly away from the now-derelict flitter, as did the buttlebot, sadly waving the melted stump of one pseudopod. I kicked it out of the way, and pushed into space. The heat at my back was knife-sharp.

  I reached the flower and curled into a ball behind it. The light flooded closer, beading the edge of my improvised shield. I imagined the nova's lethal energy thudding into the material, condensing into harmless sheets of Xeelee construction material. My suit ought to protect me from the nasty heavy particles which would follow. It was well made, based on Xeelee material, naturally... I began to think I might live through this.

  I waited for dawn. The buttlebot tumbled by, head over heels. It squirmed helplessly, highlights dazzling in the nova rise.

  At the last moment I reached out and pulled it in with me. It was the stupidest thing I have ever done.

  The nova blazed.

  The flitter burst into a shower of metal rain. The skin of the planet below wrinkled, like a tomato in steam.

  And that buttlebot and I rode our Xeelee flower, like surfers on a wave.

  It took about twelve hours. At the end of that time, I found I could relax without dying.

  I slept.

  I woke briefly, dry-mouthed, muscles like wood. The buttlebot clung to my leg like a child to a doll.

  We drifted through space. The flower rotated slowly, half-filling my field of view. Its petaled shadow swept over the wasted planet. It must already have been a mile across, and still growing.

  What a spectacle. I slept some more.

  The recycling system of my suit was designed for a couple of eight-hour EVA shifts. The Squeem did not return from their haven, light years distant, for four days.

  I did a lot of thinking in that time. For instance, about the interesting bodily functions I could perform into the Squeem's tank. And also about the flower.

  It grew almost visibly, drinking in the sunlight. Its growth was exponential; the more it grew, the more capacity it had for further growth — I did some woolly arithmetic. How big could it grow?