Children of the Comet (10 page)

Joorn was startled at Karn's vehemence. “Are you trying to tell me that you and your star pupil have had a falling-out?”

“Miles has become a megalomaniac. It's now a psychopathological condition. Twenty years of frustration will do that. And the dullards he keeps around him only encourage his fantasies.”

“What about you, Delbert? Wasn't there a touch of megalomania about your scheme to hijack the ship when the majority voted to settle down at Rebirth?”

“Maybe. It was a gamble. Maybe I was ruthless. Maybe I overreached. But I never lost sight of the realities. When the majority took back the ship, I knew it was all over. All that lovely accumulated velocity was gone. Paid back to the cosmic accounts. And now I'm resigned to being a doddering old physics teacher.”

“You, Delbert? Doddering? Never. What are you really up to?”

“Joorn, I swear …”

“Are you proselytizing Nina?

“I'm just nudging her along in physics. She's a bright little girl. She has real potential. And maybe someday she'll be fired by a grand vision of her own. I have no control over that. And neither do you.”

“And what about Martin?”

“He attends my classes, period. He knows I'm the best teacher of Higgs field physics around. He needs my help to achieve his ambition of being chief drive engineer. He's a nice boy, and he's very smart, but he was born with a monkey wrench in his hand.”

“If I thought for one minute—”

“Relax, Joorn. I have no designs on your grandchildren. Alten was another matter.” He shook his head sadly. “He could have been my intellectual heir. Instead of Oliver.”

“You be careful, Delbert. I'm keeping an eye on you.”

“You'd be better advised to keep an eye on Oliver.”

Karn swung back to his keyboard. The wall display sprang back to life. He was making no effort to conceal it. The relativistic comparisons were gone. It was all visuals now, a breathtaking close-up of one of the Milky Way's spiral arms, still recognizable despite its distortion. Karn was zooming in on one of its star systems now. It was dominated by a bloated red giant, but there was a healthy-looking orange star too, possibly a K-5, and two white dwarfs. Joorn searched and after a moment found a dim outlying red dwarf that had to be Proxima. He watched the image a few moments more, then turned and left.

CHAPTER 16

5,999,999,999 A.D.

The Oort Cloud

Ryan had posted a couple of guards outside the door to the control room, a pair of hefty fellows of his own generation who were perhaps showing a little bit of bulge at the waistline but otherwise looked quite fit. One of them smiled at Nina and said to Joorn, “Bringing the young lady along for a firsthand look, Captain?”

“Try and keep her away,” Joorn said. “Why all the security, Talbot? I thought we'd agreed that we were past the need for all that now that we're down to less than a tenth of a light.”

Talbot shrugged. “I guess Ryan doesn't want to take any chances at this stage. The intelligence boys may have stumbled onto something. There are still Karnite fanatics around, and they're not exactly rational people.”

“I'm sure their teeth are pulled, but of course President Ryan has to consider all the possibilities,” Joorn acknowledged.

The door slid open in response to some kind of a signal from Talbot, and Joorn and Nina stepped through. There were two more guards just inside, and Joorn was dismayed to see that they were equipped with wooden billy clubs from the homegrown forest maintained in an adjacent habitat by the carpentry shop. Joorn remembered the earnest debate at the last general ship's meeting.

There were those who thought that clubs fashioned from wood were an extravagance when there was plenty of cheap titanium pipe available. And an opposing side with long memories who wanted no reminder of the kind of tactics employed by the Karnite thugs when they had seized the ship years ago. Then there was the civility crowd who thought the ship's security unit should have nothing to do with any kind of clubs, wood
or
titanium.

“Morning, sir.” A sandy-haired young man wearing a grad student's chevron offered a sloppy salute that he must have copied from one of the old Earth videos.

“You've got things well in hand, I see,” Joorn said.

“Yes, sir. Security thought it would be a good idea to secure the control room before the Higgs drive was turned off. You see, the thought was that some opposition elements might get to feeling desperate when—”

“Yes, yes, Talbot filled me in. When did the order come through?”

“First dog watch, sir.”

“Very good. Carry on.”

Nina caught sight of Chu and ran across the control room to where he was seated. She stopped short of him while she decided whether he could be interrupted. When he held out his arms for a hug, she gave it to him and slid into the adjacent seat, her hands in her lap away from any knobs or buttons.

“Are you going to tell me about the trees, Uncle Chu?” she asked.

“You bet, sweetheart,” Chu said. “There's one only a few light-months away—just as soon as I can zoom in on it.”

Joorn studied his granddaughter with approval. She'd shot up quite a bit in the ten thousand years since deceleration had begun. She was now a composed young lady of thirteen, taking her first formal classes in astrophysics, well ahead of her classmates, and promising to overtake her brother, Martin.

He slid into the captain's chair and, after a nod from Chu, started to punch himself in.

“Where do we stand?” he asked.

“Everything's nominal,” Chu said. “The program's ready to go. We'll switch to the secondary drive without a hitch.”

“Where's Martin? I'd have thought he'd want to be here.”

“He's babysitting the conjugate mirror assembly with the engineering crew. He thought he ought to be there when it goes off-line.”

Joorn nodded. “Good boy.”

“Boy no longer,” Chu said.

Nina was fidgeting. “What about the trees?” she asked.

Chu's hands flew over the keys that operated the imaging system. On the viewscreen blurred specks bounced and jiggled until one of them grew into a recognizable shape as the focus seemed to race toward it, technically faster than light, though that was an effect of the computer choosing successively from millions of foci per second.

“Ah, there we are. Do you know where that is, Nina?”

“Yes, of course,” she replied with thirteen-year-old certitude. “That's in the Oort cloud.”

“Right. Actually two Oort clouds mingled together to become one. The Alpha Centauri system had its own Oort cloud, just like Sol, extending outward a couple of light-years. The two Oort clouds may actually have brushed against each other at their boundaries.”

“It was Oort all the way, pussycat,” Joorn offered, quoting the tired old classroom joke.

“I know all that!” Nina said scornfully. “It's from Astronomy One.”

Chu reprimanded Joorn with a cocked eyebrow and continued. “Then, a couple of thousand millennia ago, the net drift of the Centauri system toward the solar system resulted in a quadruple star system, with the three Centauri stars and our sun doing a complicated dance together. And the two Oort clouds became one huge Oort cloud, an enormous egg-shaped cloud containing trillions and trillions of comets surrounding the quadruple system.”

“Yes, yes, I know.” Nina was impatient. “Egg-shaped, not spherical, because it would become gravitationally stretched when the clouds interpenetrated. And because the clouds are counter-rotating in relation to each other, there'll be a tremendous confusion of the cometary traffic.” She tossed an unruly mop of dark hair. “But not a lot of comets colliding or capturing one another because on average they're so far apart.
Please
, Uncle Chu!”

Joorn grinned proudly at Chu over Nina's head.

Chu ignored him and went on patiently. “Now we come to the trees. In the very early twentieth century, the 1920s in fact—”

“Six billion years ago,” Nina interrupted.

“Yes, six billion, more or less,” Chu said dryly. “Give or take a few years, of course. In the 1920s, a scientist named Bernal speculated that if you could breed trees to live in vacuum and plant them on comets, they could grow to an enormous size. In fact, in the absence of any appreciable gravity, they could grow to heights of hundreds of miles. Quite a stretch …” He paused to give Joorn time to groan. “… at a time when his fellow scientists were arguing that space travel itself would never be possible! There were plenty of comets, and they could provide the growing Trees with all the water and trace elements they needed. What was especially remarkable about Bernal's fantastic vision was that nothing was known about DNA at the time. Genetic engineering, as we understand the term, hadn't even been imagined. Bernal was talking about good old-fashioned Gregor Mendel–style plant breeding.”

Nina's agile imagination had already made the leap. “So the Oort cloud is actually one huge forest in space.”

“By now it is,” Chu said. “The trees have had six billion years to grow and evolve. By now they've had an eternity to spread throughout the entire Oort cloud. And, probably, the Oort clouds of all the nearby stars as well—Barnard's Star, Sirius, Tau Ceti, Delta Pavonis, and beyond. In the fullness of time, I don't doubt that they'll fill the entire galaxy.”

Nina's young face showed that she was trying to digest that. “Sort of like the Others did,” she said in a hushed voice. “Except that trees don't think or communicate with each other.”

“Oh but they do, in their own way,” Joorn submitted. “Didn't you learn that in your biology class? Biology's just as fascinating as astrophysics, you know.”

“Listen to your father,” Chu said.

“What do you mean, in their own way?” Nina said, subdued now.

“Even on Earth, trees and other plants had the ability to share information and plan for a common defense against their enemies,” Joorn said. “If a tree was attacked by bark beetles, for example, it could warn its fellow trees to thicken their bark or produce appropriate toxins or repellents by sending chemical signals through the groundwater or the air.”

“There's no air in space, let alone groundwater,” Nina protested.

“In an Oort cloud filled with trillions of living things, there'd be plenty of exudations, no matter how thinned out,” Chu pointed out. “Stray water molecules from the trees' metabolism, plant hormones, individual grains of pollen. It wouldn't take much. One molecule per every cubic meter or so would constitute a medium for transmitting chemical messages, though perhaps at a rate imperceptible to us fast-living humans.”

“But why would people plant trees in space in the first place?” Nina asked. “The colonists on Rebirth are planting forests there, and we've got our own little forest for whatever wood we need right here in the ship.”

“Chu's too young to remember,” Joorn said. “He was born on Rebirth. I was raised on Mother Earth less than a century after our expansion into space began. The answer is that lots of wood was needed for construction out there, and, just as important, in the tremendous sizes provided by Bernal's trees. It dawned on our brave planners that wood was the ideal construction material for our new space age. It didn't deteriorate like plastic under ultraviolet bombardment. It didn't have to be boosted into space at great expense, let alone mined at even greater expense. And even better, it provided greater protection against killer radiation than the tin cans we were using for habitats and spaceships before then.”

Joorn paused reflectively. Chu maintained a respectful silence.

“I'm old enough to remember when the first space habitat was constructed out of vacuum-grown wood. There was a lot of hype about it, enough to fire the imagination of a small boy who wanted to be a starship pilot. And it wasn't even made of comet-grown wood under conditions of negligible gravity. The first Oortian trees hadn't matured yet. This one was carpentered together out of wood from the still-experimental lunar forests, under conditions of one-sixth Earth gravity. Those early trees only grew to a height of about half a mile.

“The construction of that first habitat was crude. It was polygonal rather than toroidal. They hadn't yet thought of those enormous planters that rotate an increment at a time to make the tree grow with the proper curvature as it keeps striving toward the vertical under one-sixth gravity. So they started with eighteen straight joists made into six equilateral triangles that were about three thousand feet on a side and as wide as a football field. Then they framed the habitat by joining the triangles to make a hexagon and went on from there.”

He smiled reminiscently. “I visited the habitat when I was a young man in training. It was in orbit around Jupiter, at a relatively safe distance beyond the orbit of Himalia. It was a little disconcerting. Gravity seemed to be straight up and down when you were standing in the center of one of those football fields, but as you walked toward the next triangle, it began to feel like walking uphill. Your eyes told you that you were walking on a flat surface, but your inner ear disagreed. It kept getting steeper and steeper till you reached the next triangle, then you were walking downhill till you reached that segment's center. People got used to it.”

Chu nodded vigorously. He was a great history buff and had always been fascinated by the romantic era of wooden habitats and wooden spaceships. His captain was a living relic, a firsthand witness of those bygone days, and whenever the duty roster made it possible, Chu enjoyed whiling away the long hours of his watch by listening to Joorn's oft-told tales.

“The day of the wooden spaceship vanished when the Higgs drive came in,” Chu said sadly. “Just as the age of sail vanished when steam power began to replace wooden sailing ships. But change was inevitable.”

“Not quite,” Joorn said. “The first starships to Alpha Centauri and Tau Ceti, which were launched before the Higgs drive with its built-in radiation shield made wooden spaceships obsolete, were made of wood. A thickness of fifteen feet of wood was safer than a metal skin. Energetic particles were absorbed, not bounced around to create killer secondary radiation, and it was more practical than embedding the living quarters inside fifteen feet of water, which did the same thing. It could handle anything from solar flares to the sleet of gamma rays you got from interstellar travel.” He chuckled. “When the first Higgs ship made it to Alpha Centauri after a five-year trip, some sixty years after a maiden expedition had been launched in one of those old wooden ships, the would-be colonists were still less than halfway across. A rescue mission was mounted to intercept the First Centauri Expedition and transfer the colonists to a Higgs ship, leaving the old wooden hulk to drift for eternity. When the original colonists arrived at Alpha Centauri, they were surprised—and a little miffed—to find a settlement already flourishing there.”

He became serious. “Of course it was only wooden spaceships that were made obsolete by the Higgs drive,” he said soberly. “Wooden habitats were still more practical than aluminum and titanium and man-made plastics. And a lot cheaper. When your grandmother and I left Earth, the habitats orbiting Mars and the gas giants were still being constructed of giant timbers harvested in the Oort cloud and the Kuiper Belt. In the fullness of time, our colonists on Rebirth will be harvesting lumber that's come to maturity in
their
Oort cloud.”

“The fullness of time's already come to pass,” Chu reminded him. “Six billion years of it. “The human race in that galaxy has long been supplanted by whatever evolution does to a species in six billion years.”

“Yes, of course,” Joorn said. “Forgive an old man. Time tends to run together at my age.”

“On the other hand,” Chu said, “the engineered trees, or whatever they've evolved into, have probably filled 3C-273 and all the galaxies in our supercluster by now.”

“Our supercluster is—was—a hundred and fifty million light-years across,” Nina said, showing off. “How could randomly drifting trees disperse through an area like that, even in six billion years?”