Charles Sheffield - Tomorrow and Tomorrow

“Are you sure it’s really happening, Mel? If the caesura is sending part of the star to another universe, why isn’t the rest of it in turmoil? Unless somehow the gravitational effect is left behind…”

“According to Cass, it’s not. The whole thing goes — mass, matter, gravitational and magnetic fields, everything. We verified that on the small tests of asteroids and planets. I see no reason to think she’s wrong this time.”

“So why isn’t there total chaos around the star?”

“Cheshire Cat effect. Cass doesn’t call it that — she uses a string of Science gibberish. But there’s a time lag before the field stresses disappear from our universe. It’s long enough to keep the star intact as it moves into the caesura. If there were colonies on the planets around the star — there aren’t, of course, they were moved long ago — and if the caesura hadn’t swallowed them, the colonies would see the star vanish but measure its residual gravitational field. That fades smoothly away over an eight-hour period.”

“Suppose the caesura moves slowly, and takes more than eight hours?”

“Then the part of the star that hasn’t been absorbed will collapse. If half of it is left behind, you’ll get an explosion with as much energy as a supernova. The nice thing is that this can be done with any type of star, and you can do it when you choose. And by picking the right caesura geometry you can beam the emitted energy in a particular direction. You can keep the beam collimated, so it doesn’t spread much over interstellar distances. Intergalactic, either, if you take extra care. And there’s your weapon.”

A weapon, indeed. The ultimate weapon. Drake stared at the doomed star, reduced now to a mere sliver of brilliance. Only a thin sector of the right-hand side remained. Then he turned to look outward, toward the galactic edge. The stars blazed there, undiminished, but they were silent. Uncommunicating, controlled by the Shiva.

He knew now the power that lay within his hands. His own idea had been to use the caesuras to create a no-man’s-land, an empty zone on the edge of Shiva territory. Even if the Shiva could cross that firebreak, the time it took would tell humans something more about the manner and speed of Shiva movement.

Now Mel was pointing out that they could do much more.

Pick a target star in the Silent Zone. Choose any planetless and expendable star in this region, or any other convenient place in the Galaxy. Create a caesura of the right dimensions and geometry.

Now if you moved the caesura to engulf your chosen star at the right speed, a tongue of energy from the stellar collapse would be thrown out into space. It would travel at a substantial fraction of the speed of light. When it reached the target star, any planets orbiting that star would become burned and lifeless cinders. The star’s outer layers on one side would be stripped off. There was a chance that the star itself would explode.

There were more than enough available stars in the human sector of the Galaxy for a one-on-one matching with stars in the Silent Zone. The Shiva, whatever they were, could be destroyed.

Whatever they were. That was the trouble. It was easy to examine the pattern by which the Shiva had entered and spread through the Galaxy from outside, and conclude from the long silence of the old human colonies that the Shiva were ruthless destroyers, inimical to anything other than their own kind.

And hence to propose the old human solution, stated by Rome but surely far older: Shiva delenda est; “the Shiva must be destroyed.”

Conclusion was not the same as proof. Suppose that the colonies throughout the Silent Zone still survived? Suppose there was some other reason for their failure to speak? The existence of the Shiva and the silence of the colonies were not the elements of a syllogism. They did not add up to a proof that the colonies no longer existed.

Drake wondered just what it would take to persuade him of that. Was he proving that the composites were wrong, when they called him back to consciousness? Maybe he was like them, lacking the resolve to do what had to be done.

He looked again at the sky, which now showed nothing at all where star and caesura had been. He turned to Mel Bradley.

“What happens to the caesura when it has done its work?”

“It just sits there, a permanent feature of space-time with zero associated mass-energy. It will never decay or go away. Don’t worry, though. I asked Cass Leemu the same question. Unless it’s activated in the right way it won’t absorb anything else. There’s no danger that the caesuras will keep going and swallow up the universe.”

“That wasn’t what I was thinking. I was wondering if a caesura could go on and eat up another star.”

“Any number. So far as we can tell there’s no limit to how much matter or energy you can put into a caesura and kick right out of the universe. But rather than move one caesura all over the place, it’s easier to make another one. Cass and I have the technique down cold.

We can make one for each star in the Galaxy — if you want us to.”

There was an implied suggestion behind Mel’s words. Which means we could make one for each star in the Silent Zone, if you wanted us to, and have plenty of the Galaxy left afterward.

It was a solution, but one that Drake could not use. Not yet. Someday, maybe, when he had exhausted every other hope, or when absolute proof was produced to show that the Shiva were the destroyers that they seemed to be. But for the moment…

“Stay here. Make as many of the caesuras as you need for the firebreak. As soon as all the colonies are relocated to a safe region, remove the stars and get the break in position.”

“Very good.” Mel sounded disappointed. “And how should I use the caesuras, fast or slow?”

“Fast enough to avoid the problem of stellar collapse.”

“If you say so. And the Silent Zone?”

“Stays silent, and untouched.” Drake looked one last time toward the outer edge of the Galaxy, knowing that colonies were disappearing from the human community as he watched. He felt Mel Bradley’s disapproval, weighted by the thoughts of hundreds of trillions of other composites across space.

“I intend to do something else about the Silent Zone,” Drake continued. “You can start the return transmission any time. As soon as I’m back at headquarters I’m going to try a new approach.”

It was one of the rare occasions when the thought of his own dissolution was preferable to the idea of what he had to do next. Dying once was not so bad. Everybody did it eventually, and it was part of your personal future even if you didn’t know how or when.

Dying a billion times was less appealing.

The location of every lost world was well known. Drake had chosen one of the most recently silenced, vanished from the human community since the time of his own involvement.

He and Tom Lambert were on board a probe ship, downloaded to an inorganic form that shared the ship’s eyes, ears, and communications unit.

Tom had taken charge of the ship’s drive. “According to the records for other similar places,” he said, “we’re approaching the danger zone. That’s the planet ahead.”

They stared in silence at the image of a peaceful world. It was a look-alike for another planet about three hundred light-years away: same K-type primary; mass, size, orbital parameters and axial tilt within a few percent; atmosphere modified very slightly, if at all, to an Earth analog. Both worlds had been colonized by a human association of organic and inorganic forms within two million years of each other. Here were sister planets, celestial twins with one difference: this world, Argentil, after billions of years of active presence in the human community, had dropped all contact and refused to respond to any signals.