Dr. Sagan, who has been listening silently with his head cocked to one side like a very intelligent blackbird, raises an eyebrow.
“Yes?” asks Brundle.
“I, uh, would you mind explaining that to me? I haven’t been on one of these committees before.”
No indeed, thinks Gregor. It’s a miracle Sagan ever passed his political vetting: he’s too friendly by far with some of those Russian astronomer guys who are clearly under the thumb of the KGB’s First Department. And he’s expressed doubts—muted, of course—about the thrust of current foreign policy, which is a serious no-no under the McNamara administration.
“A CAB is a joint committee feeding into the Central Office of Information’s external bureaux on behalf of a blue-ribbon panel of experts assembled from the intelligence community,” Gregor recites in a bored tone of voice. “Stripped of the bullshit, we’re a board of wise men who’re meant to rise above narrow bureaucratic lines of engagement and prepare a report for the Office of Technology Assessment to pass on to the Director of Central Intelligence. It’s not meant to reflect the agenda of any one department, but to be a Delphi board synergizing our lateralities. Set up after the Cuban fiasco to make sure that we never again get backed into that kind of corner by accidental group-think. One of the rules of the CAB process is that it has to include at least one dissident: unlike the commies we know we’re not perfect.” Gregor glances pointedly at Fox, who has the good sense to stay silent.
“Oh, I see,” Sagan says hesitantly. With more force: “So that’s why I’m here? Is that the only reason you’ve dragged me away from Cornell?”
“Of course not, doctor,” oozes Brundle, casting Gregor a dirty look. The East German defector, Wolf, maintains a smug silence: I am above all this. “We’re here to come up with policy recommendations for dealing with the bigger picture. The much bigger picture.”
“The Builders,” says Fox. “We’re here to determine what our options look like if and when they show up, and to make recommendations about the appropriate course of action. Your background in, uh, SETI recommended you.”
Sagan looks at him in disbelief. “I’d have thought that was obvious,” he says.
“Eh?”
“We won’t have any choice,” the young professor explains with a wry smile. “Does a termite mound negotiate with a nuclear superpower?”
Brundle leans forward. “That’s rather a radical position, isn’t it? Surely there’ll be some room for maneuver? We know this is an artificial construct, but presumably the Builders are still living people. Even if they’ve got green skin and six eyes.”
“Oh. My. God.” Sagan leans forward, his face in his hands. After a moment Gregor realizes that he’s laughing.
“Excuse me.” Gregor glances round. It’s the German defector, Wolff, or whatever he’s called. “Herr professor, would you care to explain what you find so funny?”
After a moment Sagan leans back, looks at the ceiling, and sighs. “Imagine a single, a 45 rpm record with a centre hole punched out. The inner hole is half an astronomical unit—forty-six million miles—in radius. The outer edge is of unknown radius, but probably about two and a half AUs—two hundred and forty-five million miles. The disk’s thickness is unknown—seismic waves are reflected off a mirrorlike rigid layer eight hundred miles down—but we can estimate it at eight thousand miles, if its density averages out at the same as Earth’s. Surface gravity is the same as our original planet, and since we’ve been transplanted here and survived we have learned that it’s a remarkably hospitable environment for our kind of life; only on the large scale does it seem different.”
The astronomer sits up. “Do any of you gentlemen have any idea just how preposterously powerful whoever built this structure is?”
“How do you mean, preposterously powerful?” asks Brundle, looking more interested than annoyed.
“A colleague of mine, Dan Alderson, did the first analysis. I think you might have done better to pull him in, frankly. Anyway, let me itemise: item number one is escape velocity.” Sagan holds up a bony finger. “Gravity on a disk does not diminish in accordance with the inverse square law, the way it does on a spherical object like the planet we came from. We have roughly earthlike gravity, but to escape, or to reach orbit, takes tremendously more speed. Roughly two hundred times more, in fact. Rockets that from Earth could reach the moon just fall out of the sky after running out of fuel. Next item,” another finger. “The area and mass of the disk. If it’s double-sided it has a surface area equal to billions and billions of Earths. We’re stuck in the middle of an ocean full of alien continents, but we have no guarantee that this hospitable environment is anything other than a tiny oasis in a world of strangeness.”
The astronomer pauses to pour himself a glass of water, then glances round the table. “To put it in perspective, gentlemen, this world is so big that, if one in every hundred stars had an earthlike planet, this single structure could support the population of our entire home galaxy. As for the mass—this structure is as massive as fifty thousand suns. It is, quite bluntly, impossible: as-yet-unknown physical forces must be at work to keep it from rapidly collapsing in on itself and creating a black hole. The repulsive force, whatever it is, is strong enough to hold the weight of fifty thousand suns: think about that for a moment, gentlemen.”
At that point, Sagan looks around and notices the blank stares. He chuckles ruefully.
“What I mean to say is, this structure is not permitted by the laws of physics as we understand them. Because it clearly does exist, we can draw some conclusions, starting with the fact that our understanding of physics is incomplete. Well, that isn’t news: we know we don’t have a unified theory of everything. Einstein spent thirty years looking for one, and didn’t come up with it. But, secondly.” He looks tired for a moment, aged beyond his years. “We used to think that any extraterrestrial beings we might communicate with would be fundamentally comprehensible: folks like us, albeit with better technology. I think that’s the frame of mind you’re still working in. Back in ’61, we had a brainstorming session at a conference, trying to work out just how big an engineering project a space-faring civilization might come up with. Freeman Dyson, from Princeton, came up with about the biggest thing any of us could imagine: something that required us to imagine dismantling Jupiter and turning it into habitable real estate.
“This disk is about a hundred million times bigger than Dyson’s sphere. And that’s before we take into account the time factor.”
“Time?” echoes Fox from Langley, sounding confused.
“Time.” Sagan smiles in a vaguely disconnected way. “We’re nowhere near our original galactic neighborhood and whoever moved us here, they didn’t bend the laws of physics far enough to violate the speed limit. It takes light about one hundred sixty thousand years to cross the distance between where we used to live, and our new stellar neighborhood, the Lesser Magellanic Cloud. Which we have fixed, incidentally, by measuring the distance to known Cepheid variables, once we were able to take into account the measurable red shift of in-falling light and the fact that some of them were changing frequency slowly and seem to have changed rather a lot. Our best estimate is eight hundred thousand years, plus or minus two hundred thousand. That’s about four times as long as our species has existed, gentlemen. We’re fossils, an archaeology experiment or something. Our relevance to our abductors is not as equals, but as subjects in some kind of vast experiment. And what the purpose of the experiment is, I can’t tell you. I’ve got some guesses, but…”