"We almost had it when we talked of stitching Earth out of reach," John answered eagerly. "If we keep cutting back and forth from one universe toward the other, we will be out of reach, even if we can't move very far. Once a day we reappear in this Universe for a few million-millionths of a second—although it will seem like a whole day to us.
"Then we spend the following day between this universe and beta. Even if the invaders are right on top of us when we reappear, we'll be gone again before they can do anything. Since we can vary the time of our return within limits, the invaders will never know exactly when we will flick in and out of the alpha plane until they hear our arriving 'bong' wave, and then we will already be gone, since we will be using accelerated subjective time."
The Chief Scientist shook his dark head and sighed. "No, John," he said, "I'm afraid that isn't the answer. I'm sorry. If we start the operation you suggested, we will be cutting ourselves off from solar energy. The Earth's heat will gradually radiate away. Although beta is at a higher entropy level than our universe, we can't use that energy, except to provide power for the stitching process itself. It's true that we would deny our planet to the invaders, but we would soon kill ourselves doing it."
"I didn't mean that we should transfer only Earth, but our entire Solar System," answered Bristol. "As the Oracle told us, the stitch saves nine. A series of time-matched transmitters could do the trick. If we sent the entire Solar System back and forth, the average man in the street would notice no change, except that sometimes there would be no stars in the sky. And when they were there, they wouldn't be moving."
"That would work theoretically," said the Chief Scientist. "And once we were in continuous stitching operations, any invader, as you suggested, could join the system only by synchronizing the transmitter in his ship exactly with all of our synchronized transmitters. That's a job I don't think could ever be done.
"Remember, though, that our own transmitters would have to be time-matched to within a minute fraction of a micro-second. Considering that some of the instruments would have to be so far apart that at the speed of light it would take hours to get from one to the other, the problem becomes enormous. Any radio-timing link would be useless."
Bristol nodded. "The Oracle said that the stitch must be taken in time," he agreed. "But that is no real problem. We can just send a small robot ship into inter-planar travel and let it bounce back. The 'bong' of its return will reach all transmitters simultaneously and we can use that as the initial time-pulse. Once the operation starts, it will be easy to synchronize, since we will always switch over again on the instant of our return to the alpha plane."
The Chief Scientist relaxed. "I think that does it, John. We hide in time, instead of in distance."
"We stitch in time," corrected the President, "and hide like a needle in a haystack."