“The blue-green. It diverges only one percent in fifty kilometers.”
“I hope that will be tight enough. How many microseconds after you started to send your call for help did the receivers begin to record radio noise, and how long after you stopped sending did the noise you received end?”
“I’ll have to check. It was small enough that only the instruments could pick it up—so far as I was concerned, they seemed simultaneous.” Torran moved across to the receiver displays. “Ninety-four microseconds, plus a fraction, for the delay at the beginning. And the signal went on for a hundred and sixty microseconds after my call ended.”
“That’s close enough.” Teri was at the laser station. “I’m going to send a one-second pulse from the blue-green laser. Watch the display. See anything?”
“Yes. A faint green dot showed on the screen—and it lasted about a second.”
“We’ll find when we measure it that it lasted
“
“Don’t you get it, Torran? We’re not in limbo, or in the Croquemort Timewell, or a spacetime hiatus. The ship is sitting
“Now, I’m going to assume that the velocity of propagating radiation is the same here as in open space—that seems pretty reasonable. So at three hundred thousand kilometers a second, we are fourteen kilometers away from the nearest point of the boundary, and twenty-four kilometers from the farthest point. I also find a zero Doppler shift in frequency between the outgoing laser pulses and their returns, so our ship is at rest relative to the boundary. The advantage of using laser pulses in precise directions is that we—or rather, the ship’s computer—can calculate and reconstruct the shape of the space we are inside, and also our ship’s distance from any point of the boundary. If we find places where the structure of the wall seems different, those are the logical spots where we should look for a way out.”
“Teri, you’re a marvel. Can we start that work at once?”
“I’d like to. But I think we ought to tell Julian Graves what we have learned. Do you know where he is?”
“Last time I saw him he was in his own cabin. Contemplating his navel, from the look of him. But you are right, he does need to be told. Come on.”
Julian Graves was in his own cabin. He was not actually contemplating his navel, but he was engaged in a pursuit that seemed just as unproductive. He sat in a chair, lightly strapped in position so that he would not move around in the ship’s free-fall environment. He was staring intently at a fixed point in space. Torran and Teri finally realized that a tiny green marble hung there, about a meter in front of Graves’s face.
Teri said, “Councilor, we have important news. We are not in limbo, or in some form of spacetime hiatus.”
Graves nodded. “I know. In a few minutes I was proposing to come and tell the two of you the same thing.”
Torran said, “But how could you possibly know that? You have been sitting in your cabin, and there are no instruments here.”
“Oh, but there are. The human eye and the human brain are both instruments, potentially of a high order. It is true that at no point have I looked beyond the ship itself, but I did not need to. I noticed an oddity in the control cabin some time ago. The ship’s drive appeared to be off, since we felt no accelerations. However, the drive monitors indicated that the drive was—and is—turned on, although at an extremely low level. Since our position sensors insist that we are at rest in inertial space, the only explanation is that the ship itself resides in a field of force, albeit a very weak one—far too weak to be apprehensible to human senses. If that is the case, then although the drive holds the ship itself in a fixed position, objects