“Let’s talk about all that later.” But Kate reached out, and this time she did squeeze his hand. “For the moment we have to concentrate on the model. If it’s the Commensals that are causing the trouble…”
…then we are in for a battle royal. The Commensals, and the Sylva Corporation that oversees their creation, between them have tremendous political clout. Kate didn’t need to say that to Alex. His own mother was far from unique in her willingness to do anything to restore and maintain her youth and beauty.
“We’re going to find out.” Alex set to work at the console. “I’m setting up the model to treat Commensals and unmodified humans as separate but interacting populations.” He turned to Kate. “Do you know, can someone who decides to become a Commensal change her mind, and have the process reversed to become a normal human?”
“I don’t think so. I believe it’s one-way only. If it is possible to undo it, I’ve never heard of a case where someone chose that option.”
“So we’ll assume it goes on like that.” Alex set parameters so that any member of the human population could elect to become a Commensal. The human population changed by reproduction, by transfer to Commensal form, or by death. The Commensal population could decrease only through death. An all-Commensal solar system ultimately implied an empty solar system.
He glanced at Kate. His finger hovered over a final key. She nodded. “I can’t think of anything more. Do it, Alex.”
It was the power of a god. Alex pressed. At one touch of his finger, databases all across the System came into play. Within the computer, the separate Faxes that represented more than five billion humans (and now Commensals) began to live, die, love, hate, act and interact, and move around the solar system. Days sped by too fast to follow. As the years rolled on, the full panoply of solar system activity was revealed on the displays.
Most of Alex’s attention focused on just two counts: the ratio of the number of Commensals to the total human population, and the human population itself.
The yearly aggregates came into view. By 2105, System population was a figure familiar from their previous runs: 5.6 billion. Commensals were less than one in ten thousand of humans. But the fraction was creeping up. In 2124, one percent of the human population of 7.6 billion had become Commensals. In 2134, that percentage was close to five percent.
“I think you’re right, Alex.” Kate was crowding close, no longer aloof and standoffish. “It’s the damned Commensals.”
Alex didn’t think so. He could make the extrapolation in his head. The proportion of Commensals was increasing, but nowhere near fast enough to cause problems. With ninety-five percent of the total still human, and still actively breeding, the number of people or Commensals would never start to nosedive by 2150.
But here came 2140, and trouble. The conversion to Commensals were steady at five percent. The trouble lay in the human population. Birth rates were down, along with every other index of activity. Alex and Kate sat and watched in grim silence, right to the bitter end when in 2170 the number of humans hit a flat zero. A small population of Commensals lingered on for a few years, but by 2185 that count was also down to nothing.
“That’s it.” Alex smacked his fist down on the console, ending the run. “Exactly the same results as before. Now we know it’s not the Commensals that cause the problem. Another idea bites the dust.”
“That was just one thing to try.” Kate didn’t mention that in some ways she was relieved. The idea of a solar system filled with Commensals, and only Commensals, did not appeal to her. “We can examine the effect of other important variables.”
“We could.” Alex hesitated. Did he really want to go through with this? “But there’s one other thing I’d like to do before we change variables. There is an alternate way of running the model itself, what I call Snapshot Interactive — SI — mode.”
“I’ve never heard you mention it.”
“That’s because we’ve always stressed the need for repeatable runs. You need results that you can take up the line to Mischa Glaub and Tomas de Mises, and if you have to run again you’ll always want the same answers.”
“Damn right. Alex, I don’t understand you. I know we run with a variety of possible inputs, but each run is deterministic. Except for database changes, we get the same run today as we did yesterday.”
“That’s not guaranteed in SI mode. There can be differences.”
“I think you’d better be specific. Remember, I’ll have the job of explaining all this to Mischa Glaub.”
“I’ll be as clear as I can. As you know, the big difference between my model and the ones developed in Pedersen’s group is that I include a separate piece of code for every single individual in the solar system. Each person is represented by a Fax with some level of decision-making logic of its own. The interaction of all those human-simulator components makes up the complete model. The average properties, such as transportation activity or food needs, are not regarded as independent variables. They are constructed values, built up from all those billions of separate needs.”
“I got that much from your briefing the other day. You’re saying nothing new.”
“I’m about to. When I said that individuals are represented in the model, I meant exactly that. Each person in the solar system census is in there, represented by anything from a Level One to a Level Five Fax. There’s a Mischa Glaub in the model, also a Kate Lonaker, even Cousin Hector, though I bet his Fax is smarter than he is. Most important, there’s an Alex Ligon.”
“Most important to who?”
“Most important for what I’m proposing to do next. The SI mode allows a person to take the place of his or her own Fax, inside the model. I’ve never done it before with the Seine in operation, but I’ve tried it with a reduced model in a limited environment. I know it’s feasible. I’m going to enter the model, as myself. For me it will feel like just another VR environment, same as in the media shows.” He gestured to one of the half-dozen VR helmets on the bench in front of the displays.
“Alex, you’re out of your mind. Your model runs at umpteen-million times real-time.”
“About a million, in SI mode.”
“A million, then. So the model simulates a year every thirty seconds. There’s no way your brain can possibly keep up.”
“I won’t even try. For most of the interactions, my Fax will be making decisions. Once a simulated year, I’ll have thirty seconds to review where I am, make decisions, and hand control back to my Fax. I won’t be able to change much, because my Fax isn’t powerful or influential enough for that. But with me in the program, you lose exact repeatability.”
“But why do it at all? What will you get that you can’t see right here?” Kate gestured at the displays.
“I don’t know. Immediacy? Perspective? Perhaps nothing at all. Don’t worry, I’ve done this before. It was never very enlightening, because the model was oversimplified and aggregated so much that the setting felt bogus and artificial. I’m hoping it won’t be that way now.”
“Not artificial — when you’re being jerked forward a year at a time, every half minute? Give me a break.”
“I built in a smoothing function and a neural connector designed to help with that. It ought to be that I’ll feel like I remember whatever my Fax has been experiencing.” Alex picked up one of the VR helmets. “We can talk about all this when I come out. Once I wave my hand, start the model running.”
“And then do what?”
“Watch, and wait. We’re going to run for sixty years. That’s half an hour in real-time. If I’m still in the helmet after that, drag it off me.”
“Alex!” But the helmet was going on, and Kate’s cry of protest sounded far-off and muffled. The inside of the VR helmet was totally black. The only sound was Alex’s own breath in the oxygen supply tube.