The vicinity around the construction was dotted with all manner of devices, objects, and machines, hanging in space to perform unidentifiable functions or moving on various errands. The majority were concentrated around a white, featureless hump, fifty or more feet across, sitting on a section of the structure's unfinished equatorial band. Chien glanced at Hunt. "It's an assembly processing zone in action, isn't it?" she said. This was something that Hunt had said he was particularly curious to see.
"We picked a good time for you," VISAR interjected. "This phase is just completing now."
The Thuriens didn't build things by bolting parts together the way Terrans did, in ways that had changed little since the times of Victorian factories. They grew them from the inside, by methods that were closer to the way Nature created organisms. The white hump was actually composed of fluid, constrained by a g-field shell similar to the one surrounding the maintenance platform. The fluid contained a supply of materials in various dissolved forms, and also a population of trillions of nano-assemblers programmed to extract the elements needed and incorporate them into the growing structure in precisely the way that was required at every point. In this respect, the process resembled that of organic cell differentiation, in which the cells of a developing embryo are able to activate just the correct parts of their common DNA program to turn into bone, blood, muscle, or whatever else a particular cell in the overall plan is destined to become. As they watched, the fluid inside the hump became cloudy and patchy, and seemed to go into some kind of agitation. It looked like a washing machine going into its rinse cycle.
This was new to Sonnebrandt, and in response to his questions, Duncan outlined the idea. Sonnebrandt nodded as he listened, but then frowned. "Every assembler would have to know exactly where it is to do the correct job," he said. "You said it was like biological cells. But cells can sense their relative positions in a growing organism and know which functions to switch on and which to suppress."
"They use things like chemical concentrations and electrical gradients," Chien put in.
"Yes, that's what I mean. But nothing in what Duncan just described seemed to play the role of a physical cell matrix that positional information can relate to. So how do they do it?"
Duncan looked to Hunt, who had studied the Thurien accounts more. "It's neat," Hunt said to Sonnebrandt. "The design is encoded into coordinate operators that define a high-density standing g-wave pattern throughout the construction volume. In effect, it translates it into a unique signal at every point. The assemblers decode the appropriate signal for whatever place they're at, and that tells them what to do."
"That's amazing." Sonnebrandt shook his head wonderingly. "What must be involved in computing a function like that?"
"Don't even think about trying. You'd need something like VISAR to do it."
Out on the construction, the containing shell was suddenly turned off as the process terminated. The fluid dispersed to vanish away into space in a few seconds, revealing a gleaming new layer of walls, decks, and structural members ready to be fitted out.
"Voilа," VISAR commented, sounding matter-of-fact.
Chien was looking at Hunt with an amused, slightly wry expression. "You love this kind of thing, don't you?" she remarked. "It fascinates you. As you said, 'neat.'''
Hunt didn't know quite how to reply. "Original, at least. You've got to hand it to them," he said finally.
"Were you like that as a student? Is it what Americans call nerdy?"
"Not Vic," Duncan chimed in. "He gets on with people too well. One of those popular types. Nerdy people have a problem in that area. That's why they turn to nerdy things."
"I'm not so sure," Hunt said. "I'd say it's more the other way around. Being popular is nice enough, sure… if it happens. But it's not worth spending all your time working on. There are too many things that are more interesting to spend it on. Anyway, all this business about having to be popular with everyone all the time is an American student obsession." He shrugged and looked back toward Chien. "Wouldn't you say so? What are kids like in your part of the world?"
But he saw then that Chien wasn't listening. She had turned her head and was staring at the construction in front of them again, the look in her eyes a million miles away. "Standing waves," she murmured after Hunt had waited several seconds.
"Eh?" he returned.
"Standing waves." She turned her head back and focused on him. "Defining a structure distributed through a volume of space. That's the way to halt a test object! It propagates as a longitudinal M-wave function. If we project an interference function to create a standing wave in resonance with the normal transverse solution, it will lock it into the target universe. It would force the object to materialize there."
Chien didn't have to elaborate. The others understood immediately what she meant. It sounded plausible. Forgetting all about MP2 construction methods for the moment, they put the proposition to VISAR there and then. From a theoretical standpoint, the machine could find no flaws. But only experiment could give the final word. "Can you connect me to Eesyan again?" Hunt asked.
"He is in conference right now," VISAR cautioned. Which was about as close as Thuriens were likely to come to refusing. Hunt knew it would be a violation of normal protocols to press the matter. But this was too exciting to sit on.
"I'll risk it," he said. "Offer apologies, but tell him I insist."
Eesyan appeared in a window in Hunt's visual field after a short delay. "Yes, Vic?" he acknowledged. While Eesyan's manner remained polite, VISAR injected an unmistakable undertone into its voice reconstruction that said this had better be good. Hunt summarized what had been said as briefly as he could and asked Eesyan's opinion. Eesyan was silent for what began to seem a long time. For a moment, Hunt feared that he really had offended Thurien sensibilities in a way he hadn't been prepared for. And then he read from the Thurien's face that he couldn't have been more wrong. This was good. Eesyan was going over the implications intently in his mind, far removed from whatever other business he had been attending to. Then VISAR came through for Hunt again.
"And I've just got an incoming call from the link to Earth comnet."
Earth? Probably Gregg Caldwell. It would have to be something urgent. "Sure, put it through," Hunt said absently while he waited for Eesyan's reaction.
But the face that appeared in VISAR's window was unfamiliar: fleshy and rounded, wearing an expression of implacable relentlessness. "Dr. Hunt?" it inquired.
"Er… yes."
"Dr. Victor Hunt, of the Advanced Sciences Division, UNSA at Goddard?"
"Yes. Who's this?"
"Lieutenant Polk, FBI, Investigations Branch, Finance and Fraud Division. I understand that you are acquainted with a Gerald Santello, Dr. Hunt."
What in hell was this? It couldn't have come at a worse time. "Not now, VISAR," Hunt muttered. "Cut the link. Tell him there's a technical hitch or something."