Alex was hesitant at first. How much, if anything, did the other know of computer modeling? He began slowly, giving the sort of general explanation that would suffice for upper management, until Bat scowled and said, “Details, please, root and branch. Generality and vagueness are the refuge of scoundrels, politicians and bureaucrats.”
Put that way…
Alex began to describe his work at a deeper level, encouraged by Bat’s close attention and occasional nods. When he reached the tricky subject of the predicted extinction of humanity, and the dependence of that on exogenous variables, Bat blinked and nodded.
“I, too, have had intimations of approaching catastrophe throughout the solar system. The evidence I have seen is tenuous, but it suggests disaster much closer than a century away. Did your program take account of the possible effect of new weapons left over from the Great War?”
Alex shook his head. “I didn’t include them, because I have never heard of any such thing.”
“Very well. There are two other anomalous factors that you might wish to take into consideration. First, a small group of genetically modified humans was created as a by-product of the Great War. So far as I know, they live quiet and productive lives, but their possible impact on future events cannot be discounted.”
“I know about them, and I’ve run the model with and without their presence. The results do not changed significantly.”
“Very good. Then there was a group of humans of apparent great longevity, near-immortals who were active on Ganymede but vanished a generation ago. Nothing has been seen of them since, and it was conjectured that they chose to remove themselves to the far reaches of the outer system. However, they also might be significant to the future.”
Alex nodded. “I knew of them, too, and I ran the model both ways, with and without them. They also made no difference.”
“Then for the moment I have no other suggestions.” Bat glanced again at the display of blocked communications. “Let us return to the question of the effect of aliens. Can you describe how their presence affected your predictive model results?”
“I can do a lot better than describe.” Alex fumbled in his travel bag and produced the data cube. “I can show. Here are all the programs and the results. We can — oh, no, I guess we can’t. With access to outside communication blocked, we can’t get to the Seine. My models really suck up computer resources.”
“Such resources, fortunately, are available.” Bat looked smug. “Long before the Seine was activated, I foresaw dangers and difficulty in ensuring the privacy of my work. To be honest, one of my principal concerns was other members of the Puzzle Network. Cheating on a puzzle is by no means forbidden, including infiltration of another’s databases. For that reason I established an independent computer capability here on Pandora. I call it the Keep. It is fully disjoint from all aspects of the Seine, and I would be surprised if your model is unable to run on it.”
Alex was dubious. “When I said my model eats computer time and resources, I really meant it.”
Bat inclined his massive head. “I do not doubt you. I merely say, try, and see. One of us, I suspect, will be surprised.”
Bat had been referring to computer resources. Alex, as the runs proceeded, was astonished for quite other reasons.
The computer capacity available within the Keep was everything that Bat had suggested, with far more power than had been accessible to Alex prior to the arrival of the Seine. The predictive model ran fast, even at a high degree of detail. The cause of Alex’s amazement, however, lay elsewhere.
He began by repeating the series of runs in which an alien influence was assumed to be at work in the solar system, sometime in the next half century. He duplicated exactly the runs that he had already made, and was not surprised to find exactly comparable results.
“You see, everything remains stable,” he said to Bat. “No storage overflow, no solar system collapse, no end to humanity.”
“A comforting conclusion, since in that time frame we might reasonably hope to be present ourselves.”
“Right. But now see what happens when I make the same runs, and don’t introduce any alien influence as a variable.”
Again, it was an exact repeat of earlier runs that Alex had made. He sat back and waited for the instabilities to creep in, slowly at first and then catastrophically after half a century. He was so convinced of what he would see that he did not pay full attention to the results. Only when the time marker reached 2188, with a human population steadily growing and all variables within reasonable ranges, did he jerk up straight in his chair.
“That can’t be right!”
“No?” Bat had also been relaxing, watching the near-hypnotic march of numbers and graphics across the displays. He leaned forward, frowning. “Forgive me if I appear a little lacking in perception, but I fail to see any anomalies.”
“That’s what’s wrong with it.”
Bat, mysteriously, said, “The dog in the night?”
Alex ignored that and pointed to the year, now 2190, and the display of population, which was approaching twelve billion. “It never did that before. Without an alien influence as an exogenous variable, the model always reached a crisis point about 2140. Population never rose beyond a maximum value of ten billion.”
“There is a simple explanation.” Bat sounded unimpressed. “Either you had a problem with the model in your earlier runs, or you have one now.”
“You don’t understand. It’s the same model. I simply downloaded a copy before I left Ganymede. It must be your computer. It’s not powerful enough to run my model.”
“Never.” All signs of boredom in Bat vanished. “The Keep contains resources more powerful than any Ganymede facility.”
“You said you don’t have access to the Seine when you’re running in this mode.”
“That is true, but not relevant. If it is simply computer speed that concerns you, the computers in the Keep should be more” than adequate. Were you drawing on the Seine for other elements of the computation?”
“I’m sure I was. But I don’t see any way it could change the model results. Are you suggesting that the Seine itself might destabilize my predictive model results?”
“At first sight, I agree that sounds like a preposterous notion. But what do we really know of the Seine, and how it operates? Have you run your model sufficiently?”
“Sufficiently to confuse me totally.”
“Then with your permission, I will determine the external situation.” Bat touched half a dozen points on the console. “Hm. Incoming signals remain inaccessible. However, that is no bad thing… I must think…”
Bat closed his eyes and turned into an obsidian statue. Alex stared at the vast figure, motionless on the padded seat, and declined to interrupt. He had plenty to occupy his own mind. He turned his attention again to the display. It had advanced another twenty years. Every parameter showed reasonable values. According to his model, humanity was doing fine a hundred years from now.
The Seine as a factor? That raised a whole new series of questions. The Seine had access to every data bank in the System. It could and would use whatever information the model called for. But at the level of sophistication and complexity of the predictive model, there was no way that any human could hope to track the entirety of data in use — not even for one day of prediction, never mind a century.
So where did that leave Alex? He had stuck his neck way out, assuring everyone from Kate all the way up to Magrit Knudsen that with the Seine his predictive model would give correct results. All he needed was adequate computational power. But there was a built-in assumption: the only thing that the Seine was supposed to do was compute. The results of a model should not depend on the computer on which it was run. However, since the Seine also had the power to bring in System-wide data sets which the computer deemed relevant to the computation, then the exact reproduction of any results could not be guaranteed. What data might the Seine possess to indicate that a solar system future without alien presence was unstable and doomed to human extinction, while a future containing an alien presence was stable? And why did the Keep’s computer, aliens or no aliens, predict a future without a fatal collapse?