The Heart of the Comet

by David Brin

  Quiverian waved his hand impatiently. “Yes, yes, that old theory. Aluminum 26 and other short-lived elements must surely have created some molten channels, for a time.”

  “I’d started trying to develop a biogenesis model based on that idea. But now you say it’s no good anymore?”

  Quiverian edged forward eagerly. “Radioactives can’t have provided sufficient heat for all the melting we’ve observed! And they don’t explain the extent of fractionation we find, either!”

  “Fractionation?”

  “The degree to which elements and minerals were separated from each other by some dynamic process, forming these ore bodies we’ve found everywhere. Saul, the radioactives theory just couldn’t explain that! You see? That is why I started digging around the literature for another method, another way it might have happened.”

  Saul stood closer to the table. “Well, it sure sounds interesting, Joao. I was just telling Nick Malenkov that there didn’t seem to be enough—”

  “Bear with me a minute, Saul.” Quiverian held up a hand as he shuffled through a pile of readouts. “There is something I want to show you. I have it here somewhere.”

  “Take your time, Joao.” Saul shrugged. For now he was content to enjoy a momentarily clear head—the almond-flavored air was, for once, fresh in his nostrils. He watched the computer’s slowly rotating depiction of the comet’s nucleus.

  Seismic studies had filled most of the three-dimensional map with a vague gray and white tracery, showing in blurry outlines the locations of many of the major faults and cavities. Still, essentially all but a small fraction of the rough globe remained mysterious—a realm to be explored over the long, quiet watches ahead. Less than five percent of the volume, centered on the north pole, was at all well known.

  Piercing the north rotation axis was a narrow orange line marked SHAFT 1, which dropped a kilometer straight down to an ant colony of chambers labeled CENTRAL CONTROL COMPLEX—including this lounge and most of the science labs. That shaft continued inward another two kilometers or so, terminating, at last, less than halfway to the center of Halley Core.

  Along the way, Shaft 1 met a series of horizontal tunnels, starting with red-colored “A” near the surface, passing green “F” here, where they now stood, and ending in yellow “N.”

  The pattern was a lot less neat elsewhere. Several passages opened into big caverns that the spacers had discovered the hard way. Three huge chambers now held the fore sections of the slot tugs Sekanina, Whipple, and Delsemme, and the majority of the sleeping colonists. Another, near the surface, now held the Edmund Halley’s nearly reassembled gravity wheel.

  The computer-generated graphics were good, showing even the field of storage tents scattered among the hummocks up on the north pole. A finely detailed model of a partly dismantled torch ship hung in miniature near the tiny, glittering Shaft 1 airlock, tethered to three mooring towers.

  Saul shifted forward and saw that two tiny dots moved about near the Edmund Halley—infinitesimal human shapes … Captain Cruz and Spacer Tech Vidor were running inventory and writing up a task list for the next dozen year-and-a-half-long watches. The computer showed them at work, going over the ship in detail.

  He imagined that if he climbed onto the table and peered up close, he would be able to make out the name-chops on the two spacers’ suit tabards, and maybe watch them gesture to each other.

  Saul was used to computer representations in his work. He routinely “dove” visually into the cellular lifeforms he was studying. Still, he found this display marvelous. Anywhere within reach of the main computer’s scanners one could zoom in and see animated versions of the dozen active crewmen… reduced to stereotypes by the machine’s automatic privacy editor. Likewise, the private quarters were black cubes strung out along Tunnels E, F, and G, impervious to the exquisite simulation.

  Spacers were used to living in enclosed volumes. In fact, to them all this room must seem wonderful. But to the civilians, like Saul, the colony looked a lot like an ant farm.

  A fine lot of troglodytes we’ve become. Regular kobolds.

  And yet I can’t see anything wrong with Miguel’s arrangements. Everything is moving along according to plan.

  Knock on wood. Saul rapped the side of his head lightly, and smiled.

  Even the predictable furor over his discovery had been less bother than expected. The communications time lag from Earth had let him stack media interviews together. The more hostile or sensationalist questions could just be “lost in transmission.” Saul saw definite advantages to making major discoveries far away from the madding crowd.

  Now, if only he could figure out how it happened that primitive prokaryotic organisms were found frozen under the surface of an ancient ball of ice! Nobody had any idea how the tiny creatures had gotten there, let alone how they had lived.

  “Found it!” Quiverian announced. He snatched up a flimsy sheet. “As I was saying, I was at a loss to explain all the signs of past melting we see here… until I came across a whole series of citations having to do with inductive heating during the sun’s T Tauri phase!”

  “I beg your pardon?” Saul balanced forward on his toes, leaning lightly against the table.

  Quiverian’s lips pursed. “Oh, they wouldn’t have included much stellar physics in your second-hat training, would they? Well, let me see if I can explain. T Tauri is the name of a certain very new star in the constellation of the Bull; a whole class of objects was named after it. Scientists have been studying them over a century. They’re a phase really, in the development of a young star. Our sun must have passed through the stage, early in the creation of the solar system.”

  Quiverian laced his long fingers together and looked out into space, as if he was reciting from memory. “The most interesting feature of a T Tauri star is its truly incredible stellar winds—fluxes of hot protons and electrons, blown away from a star by sonic force and by electrical—”

  “I know what the solar wind is, Joao,” Saul said mildly.

  The other man’s eyes seemed to flash. “Good! But what you probably do not know is that during the sun’s own T Tauri period the winds must have been many thousands of times greater than they ever get now. And this particle current carried a truly magnificent magnetic field.”

  Quiverian looked at him expectantly. But Saul could only shake his head. “I’m sorry, I don’t get it.”

  The Brazilian shrugged in frustration. “Ignorant biologist! Can’t you see? The early protoplanets and comets all passed through this great magnetism as they circled round and round the newborn sun. Like wires turning in a great generator! Eddy currents! Resistance!”

  “Ah, mazel!” Saul clapped his hands together. “You would get inductive heating.”

  Quiverian sniffed. “So they did teach you something in Haifa, after all. Can you see now? Do you understand?”

  Saul nodded. His mind was already racing ahead. “The newly formed comet’s surface, exposed to space, would remain cold… an insulating blanket. Even if most of the interior were molten water, the heat wouldn’t escape.”

  “Right! Of course it works only under certain conditions. You need a very large comet, like Halley, and lots of salts or free electrolytes, as we have found here:”

  Unconsciously, Saul lifted all his slight weight off the floor by stretching his hands against the table. His body was tense from too much lab work and too little exercise. Perhaps soon he would have to accept Mike Cruz’s offer to teach him spaceball.

  “How long does this T Tauri phase last?”

  “A few million years. Not very long. But long enough to create these deep chambers we found! And with all that electricity running around, it’s easy to see how so many compounds got separated into thin veins all over the core!”

  Quiverian clearly had a right to be elated. The man had envied Saul his discovery and attention in the Earthside press, but now he had reported an achievement of his own. It would doubtless be a sensation, especially in the Brazilia
n papers.

  “Congratulations, Joao,” Saul said sincerely. “This is really tremendous. Can I have this copy of your reference list to look over?”

  “Take it. Take it. I have already sent a preliminary report.”

  Ideas were fizzing like sparkles of gas in Saul’s mind. “I think this will help me in my own studies, Joao.”

  “I’m glad. But you know, this is going to require a very complex computer simulation. I don’t want to request Earth assistance until this thing is better developed.

  “Can you help, Saul? You are good at that sort of thing.”

  Saul shrugged. “As a dilettante, I guess. But one of the greatest experts is on this very watch crew with us, Joao. Why not ask Virginia Herbert?”

  Quiverian looked uncomfortable. “I do not think this Herbert woman would be very cooperative. Her type…” He shook his head, letting the implication hang.

  Saul was pretty sure he understood what the man meant. He had heard it before.

  “Their kind has always been a problem.”

  “Their kind…”

  Quiverian shifted nervously. “These Percells are a closed, uncooperative lot, Saul. I don’t think she would be willing to help a scientist from my country.”

  Saul could only shake his head. “I’ll talk to her and let you know, Joao. What do you say we meet here again for lunch, tomorrow. And we’ll include Nicholas in the discussion.”

  He was grateful when Quiverian merely nodded moodily and sighed. “I shall be here.”

  As Saul left, the planetologist was staring at the slowly turning holographic glow, his sharp features bathed in colored shadows. It occurred to Saul, then, that Quiverian was not looking particularly well.

  The fellow really ought to get more sleep. It might improve his outlook on life.

  * * *

  An hour later, Saul was at work in front of his own display, mumbling instructions into a subvocal mike and fumbling with the computer grips, struggling to keep up.

  Ideas were coming faster than he could note them down, let alone integrate them into the new model. Every time he explored one aspect, a whole vista of unexpected ramifications would leap out at him.

  It was the true creative process—a sort of divine, nervous transport—as painful as it was exalting.

  But he could almost see it. There it was—flickering like a willo’-the-wisp—a light glimpsed across a fog-swirled swamp. A theory. A hypothesis.

  A way that a mystery might have come to Comet Halley.

  Saul had sorted through terabytes of raw data the expedition had accumulated about the comet, tracing ingredients as they might have been stocked in the sun’s early pantry. They were all there, but the right kitchen had been lacking.

  Joao Quiverian’s references seemed to offer the crucible Saul had been looking for.

  The T Tauri phase…Saul mused. In its infancy, the sun was an unruly child. In those days, the star’s breath had been charged and hot.

  So there had been electricity—great. But how much, for how long?

  There were hydrogen cyanide and carbon dioxide and water—as must have saturated the primitive atmosphere of Earth—so the basic amino acids would have formed quickly. But the next steps would be harder.

  The three-dimensional network of interrelationships on his central display grew more and more unwieldy, a towering, tottering edifice built up from tacked-together assumptions.

  “Ach! May your goats chew on cordite and then give you copious milk!”

  He cursed the machine in Arabic, a more satisfying tongue for such purposes than English. His fingers felt like clumsy sausages, and the arcane math he had brought in from the astronomy papers danced just outside of reach. He couldn’t quite integrate the equations into the overall scheme he had in mind.

  For one hour, two, three, he pushed away at it. But the damn thing just wouldn’t gel.

  Saul tried brute force, pulling in block after block of external memory, more and still more parallel processors to iterate the problem. It was far from an elegant approach…more like looking for a house in the dark by sending a herd of elephants stampeding into the night, hoping to learn something from the sound of splintering wood.

  I’m doing this all wrong. I should go and have a beer. Listen to some Bach. Tune the wall to show a Polynesian sunset. Let it sit.

  Saul drummed his fingers.

  Maybe I should ask for help.

  He sat there in the web-chair, weary not so much in the body as in the mind, in the heart.

  This was the only joy left in his life, the quest for mysteries. And still he felt like a small boy—frustrated and vexed—whenever Nature seemed to want to wrestle with him, to make him wheedle and cajole her secrets out of her, instead of surrendering them easily, without a fight.

  How many of life’s pleasures are painful in the actual process? Miriam, forgive me, but you always knew that I loved Life, Nature, just a little more than you and the children, didn’t I?

  And here I am, getting cranky because my oldest love won’t put out again.

  Saul blinked and sat up. The sudden movement sent him hovering over the webbing, but he hardly noticed.

  What in the…

  Unbelievably, something was happening on the display right before his eyes. A ripple of change.

  It started off in the upper right quadrant of the computation. All at once, elements had begun to grow fuzzy around the edges. Indistinct, random bits jostled one another. Then, impossibly, the Gordian knot of logic began unraveling!

  At first he thought the entire mess was falling apart of its own inertia.

  Then he changed his mind.

  Minnie, mother of pearl…

  Out of chaos, simplicity was taking shape. Out of ugliness—beauty!

  It was like watching a solution precipitate into a gorgeous, growing crystal. Wonderful… yes. Too wonderful.

  Something or somebody was intervening, he decided. And Saul quickly realized something else: that this whoever… or whatever… was clearly a lot smarter than he.

  Equations cleaved, as if sliced by RNA nuclease. The pieces fell apart, while he stared. They arrayed themselves in stacks, row by row, piling neatly into a glowing pyramid of logic. And at the apex…

  Saul breathed rapidly as he looked at the culminating formula. He could feel his own pulse pound.

  “I’m sorry I interfered without asking permission, Saul. But you were stomping all through the data system by the time I noticed. Sooner or later you were bound to set of alarms.”

  Saul found his voice.

  “That’s all right, Virginia. I… I’m grateful for the help.”

  There was a brief pause. Then a holo-unit display to his left came alight and Virginia Herbert’s face wavered and smoothed, a replica in rich color that still hinted of salt breezes and tropical sun. Her long black hair flowed over her shoulders, slightly puffed, as if it had been hurriedly brushed just moments ago.

  “I’m glad you’re not angry with me for butting in.”

  “Angry!” Saul laughed. “You saved one of us, either me or this obdurate machine!”

  Virginia smiled. “Well, it’s a relief to know I did the right thing. Actually, that’s pretty complicated stuff you’re dealing with there, Saul. I can’t pretend to understand any of it. I’m just a glorified numbers jockey.”

  “I disagree.” Saul shook his head firmly. “You are an artist.”

  Virginia ’s olive skin darkened perceptibly. Her “Thank you” was barely audible. Saul shared a long smile with her.

  Virginia ’s eyes darted. “Um, if you’d like, you could come on down here and we’ll put JonVon to work on your problem. He’s a stochastic processor, you know. And I happen to believe that makes him a lot more applicable to the kind of problem you’ve got there than these old parallel precision machines.

  “I’m sure we can whip up a simulation to make that one there look like a stick figure cartoon.”

  Saul nodded. “Only if you let me br
ing a bottle, Virginia. I have a feeling we’re going to need it.”

  “Done!” she said gladly.

  As Saul was getting up though, a stretched image of Virginia ’s arm reached out across his desk—like an India-rubber man—to tap with one finger at the glowing, throbbing line of gold lettering at the top of the tall pyramid of data.

  “What is that anyway, Saul? Is it something special?”

  He shrugged. “Well. I guess you could say so, Virginia. It’s the chemical symbol for something called a purine base. A rather simple one, really, called adenine.”

  Virginia withdrew her ghostly, representative hand. “Well, I hope it’s important. But whether it is or not, I’ll bet we’ll be taking this a whole lot farther. I have a feeling for these things, you know.”

  She smiled brilliantly.

  “See you down here in a few minutes, Saul. VKH out.” Her image vanished.

  Saul stood still for a moment. “Yes, dear,” he said at last to the presence she seemed to have left behind. “I do believe we are going to take it quite a bit farther.”

  VIRGINIA

  MOLECULAR STRANDS, LIKE MULTICOLORED STAIRCASES…LIGHTING FLASHING IN THE DARKNESS…

  At the simulation’s finest scale, the molecule was little more than a stylized ladder put together from standard pieces—bright, slivers of blue, green, and red—amino acids, phosphates, and simple sugars linked like ill-sorted parts of an intricate jigsaw puzzle.

  The chain seemed to twist and writhe as it tumbled in a churning stream. A tracery of silvery lines stitched out electric currents, crackling unevenly through the salty fluid.

  Shiny golden radicals smacked into the growing polymer. Most bounced off again in sudden flashes of light. Occasionally one knocked a fragment loose into the flow, diminishing the molecule, leaving a hanging, ragged corner. A little more often, the colliding chunk found a niche with the right shape, and stuck.