Space

BUT, Cassiopeia said, SOME OF THESE EVENTS ARE… EXCEPTIONAL.

They were shown a cascade, image after image, burst after burst.

Some of the collapses involved particularly massive objects. Some of them were rare collisions involving three, four, even five objects simultaneously. Some of the bursts were damaging because of their orientation, with most of their founting, ferocious energy being delivered, by a chance of fate and collision dynamics, into the disc of the Galaxy, where the stars were crowded. And so on.

Some of these events were very damaging indeed.

FROM THE WORST OF THE EVENTS THE EXTINCTION PULSE PROCEEDS AT LIGHT SPEED, SPILLING OVER THE GALAXY AND ALL ITS INHABITANTS, ALL THE WAY TO THE RIM AND EVEN THE HALO CLUSTERS. NO SHIELDING IS POSSIBLE. NO COMPLEX ORGANISM, NO ORGANIZED DATA STORE, CAN SURVIVE. BIOSPHERES OF ALL KINDS ARE DESTROYED…

So it finishes, Madeleine thought: the evolution and the colonizing and the wars and the groping toward understanding. All of it halted, obliterated in a flash, an accident of cosmological billiards. It was all a matter of chance, of bad luck. But there were enough neutron-star collisions that every few hundred million years there was an event powerful enough, or well-directed enough, to wipe the whole of the Galaxy clean.

It had happened over and over. And it will happen again, she saw. Again and again, a drumbeat of extinction. That is what the Gaijin have learned.

“And for us,” Malenfant growled, “it’s back to the fucking pond, every damn time… So much for Fermi’s paradox. Nemoto was right. This is the equilibrium state for life and mind: a Galaxy full of new, young species struggling out from their home worlds, consumed by fear and hatred, burning their way across the nearby stars, stamping over the rubble of their forgotten predecessors.”

…And this is what the Gaijin tried to show me, Madeleine recalled, on my first Saddle Point jaunt of all, to the burster neutron star: the star lichen, fast-evolving life-forms wiped out by a stellar fluke every fourteen seconds. It was a fractal image of this, the greater truth.

The Galaxy image abruptly receded, the spiral arms and the core and the surrounding halo imploding on itself like a burst balloon. Madeleine gasped at the sudden illusory motion. The world congealed around her: grass and trees and that black sky, all of it illuminated by fierce blue cosmic light. She was flooded with intense physical relief, as if she could breathe again.

But her mind was racing. “There must be ways to stop this. All we have to do is evade one collapse — and gain the time to put aside the wars and the trashing, and get a little smarter, and learn how to run the Galaxy properly. We don’t have to put up with this shit.”

Malenfant smiled. “Nemoto always did call you a meddler.”

BUT YOU ARE RIGHT, the Gaijin said. SOME OF US ARE TRYING…

Ahead of them, she saw a group of Neandertals. They were dancing, signing furiously to each other, jumping up and down in the light of the cosmos. Something was changing in the sky, and the Neandertals were responding.

She looked that way. That cosmic light point seemed to be expanding.

The unwrapping sky was full of stars. It was the center of the Galaxy.

Malenfant was confronting the Gaijin. “Cassiopeia,” he said softly, “what has all this got to do with me?”

MALENFANT, the Gaijin said, YOU ARE OUR BEST HOPE.

And now the Gaijin turned with a scrape of metal, a soft hiss as her feet sank deeper into the loam.

IT IS RISING.

She turned and began to stalk across the meadow, with that stiff, three-legged grace of hers, away from the stand of trees. Madeleine saw the Neandertals were following, a shadowy group of them, their muscles prominent in the starlight.

Malenfant grabbed her hand.

They walked through a meadow. The grass was damp, cool under her feet, and dew sparkled, a shattered mirror of the stars.

They were all immersed in diffuse shadowless light, in this place where every corner of the sky glowed as bright as the surface of the Moon. The light was silvery, the colors bleached out of everything; the grass was a deep green, the leaves on the trees black. Madeleine wondered vaguely if there was enough nourishment in that Galaxy light to fuel photosynthesis, if life could survive on a rogue, sunless planet here, just eating the dense starlight.

They topped a ridge and looked down over a broad, shallow valley. There were scattered trees and standing water, ribbons and pools of silver-blue, all of it still and a little eerie in the diffuse starlight.

The Gaijin, Cassiopeia, had stopped, here at the crest. The Neandertals had gathered a little way away, along the ridge, and they were looking out over the valley.

But now one of the Neandertals came shambling toward Malenfant, with that clumsy, inefficient gait of theirs. It was a man, stoop-shouldered, the flesh over his ribs soft and sagging, and sweat slicked over his shoulders. That great brow pulled his face forward, so that his chin almost rested on his chest.

“Hello, Esau—” Malenfant said.

Esau slapped him, and his fingers rattled, his fist thumping his forehead.

Malenfant grinned, and translated. “Hello, Stupid.” Malenfant seemed genuinely pleased to see this old Neandertal geezer again.

But now Cassiopeia stirred, and Madeleine grabbed his arm. “Malenfant. Look. Oh, shit.”

A new star was rising above the valley, over the newly revealed horizon, brighter than the background wash.

It was a neutron star, a brilliant crimson point. Near the star there were multiple lobes of light. They contained structure: veins and streamers, something like the wings of a butterfly around that ferocious, dwarfed body. They glowed pink and an eerie blue, perhaps through the synchrotron radiation of accelerated electrons.

And there was something alongside the star. It looked like netting — scoop shaped, like a catcher’s mitt, facing the star as if endeavoring to grasp it.

Obviously artificial.

Cassiopeia spoke. OUR JOURNEY IS NOT YET DONE, MALENFANT. WE MUST PENETRATE THE GALACTIC CENTER ITSELF. THIS IS WHAT WE WILL SEEK.

“This is the site of a gamma-ray burster,” Malenfant said. “A future reboot event. I’m right, aren’t I, Cassiopeia?”

THE STAR’S COMPANION IS AS YET SOME DISTANCE AWAY — BILLIONS OF KILOMETERS, IN FACT, TOO REMOTE TO SEE. AND YET THE CONVERGENCE HAS BEGUN. THE COLLISION IS INEVITABLE. UNLESS—

“Unless somebody does something about it,” Madeleine whispered.

That strange artifact continued to ride higher in the sky, like a filmy, complex moon. It was a net, cast across the stars. It must have been thousands of kilometers wide.

Madeleine found it impossible to believe it wasn’t a few meters above her head, almost close enough for her to just reach out and touch. The human mind was just not programmed to see giant planet-spanning artifacts in the sky. Think of an aurora, she told herself, those curtains of light, rippling far above the air you breathe. And now imagine that: It would hang there far beyond any aurora, suspended in space, perhaps beyond the Moon…

But there was something wrong: the netting was obviously unfinished, and great holes had been rent into its structure.

“It’s broken,” Malenfant said.

YOU WOULD CALL THIS A SHKADOV SAIL, the Gaijin said.

It would be a thing of matter and energy, of lacy rigging and magnetic fields: a screen to reflect the neutron star’s radiation and solar wind. But it was bound to the star by invisible ropes of gravity.

“Ah,” Madeleine said. “You disturb the symmetry of the solar wind. You see, Malenfant? The wind from the star will push at the sail. But the sail isn’t going anywhere, relative to the star, because of gravity. So the wind gets turned back…”

“It’s a stellar rocket,” Malenfant said. “Using the solar wind to push aside the star.”

THAT IS THE PURPOSE. WHEN COMPLETE IT WILL BE A DISC A HUNDRED THOUSAND KILOMETERS ACROSS, ALL OF IT LACED WITH INTELLIGENCE, A DYNAMIC THING, CAPABLE OF SHAPING THE STAR’S SOLAR WIND, RESPONDING TO ITS COMPLEX CURRENTS.

Malenfant grinned. “Hot damn. Somebody is fighting back.”

“Who is building this thing? You?” Madeleine asked.

NOT US ALONE. MANY RACES HAVE COME HERE, COOPERATED ON THE SAIL’S CONSTRUCTION. IT APPEARS TO HAVE BEEN A RELIC FROM A PREVIOUS CYCLE, FROM BEFORE A PREVIOUS REBOOT.

“Like the Saddle Point network.”

Madeleine peered doubtfully at the huge, unlikely structure. “How can a sail like that move a neutron star — an object more massive than the Sun?”

THE THRUST IS VERY SMALL, THE ACCELERATION MINUSCULE. BUT OVER LONG ENOUGH PERIODS, SMALL THRUSTS ARE SUFFICIENT TO MOVE WORLDS. EVEN STARS.

“And will that be enough to stop the coalescence of this binary, to stop the reboot?” Madeleine asked.

NOT TO STOP IT. TO POSTPONE IT GREATLY, BY ORDERS OF MAGNITUDE. IF WE CAN DELAY THIS STERILIZATION EVENT—

“We might win time,” Malenfant said.

Madeleine challenged the Gaijin. “Is this really the best option? Haven’t you come up with anything smarter?”

Malenfant eyed her. “Like what?”

“Hell, I don’t know. You could use antigravity. Einstein’s cosmological constant, the force that makes the universe expand. Or you could interfere with the fundamental constants of physics. For example there is a particle called the Higgs boson, which gives matter its mass. If you took it away, switched it off, you could make your neutron stars lighter, and then just push them aside. In fact, take all the mass away and they would fly off at the speed of light. Easy. Give me a lever and I will move the world…”

WE HAVE NO SUCH POWERS, Cassiopeia said, and Madeleine thought she detected sadness in that synthesized voice. WE HAVE SEARCHED. THERE IS NO CIVILIZATION SIGNIFICANTLY MORE ADVANCED THAN OUR OWN — EVEN BEYOND THE GALAXY.

IT IS LIKE YOUR FERMI PARADOX. IF THEY EXISTED, WE WOULD SEE THEM. IMAGINE A GALAXY WITH ALL THE STARS FARMED, COVERED BY DYSON SPHERES, THEIR PHYSICS ALTERED PERHAPS TO EXTEND THEIR LIFETIMES. IMAGINE THE GALAXY ITSELF ENCLOSED BY A DYSON STRUCTURE. AND SO ON. EVEN SUCH CLUMSY ENGINEERING, ON SUCH A SCALE, WOULD BE VISIBLE. WE SEE NO SUCH THING, AS FAR OUT AS WE LOOK, AS DEEP INTO SPACE AND TIME.

But it wasn’t a surprise, Madeleine thought. How long would it take a galactic civilization to rise — even supposing somebody could survive the wars and assorted despoliation? Because of light speed, it would take a hundred thousand years for a message to cross the Galaxy just once. How many such exchanges would it take to homogenize the shared culture of a thousand species, born of different stars and biochemistries, creatures of flesh and metal, of rock and gas? A thousand Galaxy crossings, minimum?

But that would take a hundred million years, and by that time the next burster would have blown its top, the next reboot driven everybody back to pond scum.

So maybe this clumsy net really was the best anybody could do. But still, good intentions weren’t enough.

“Tens of millions of years,” she said. “You’d have to maintain that damn thing for tens of millions of years, to make a difference. How can any species remotely like us, or even you, maintain a consistency of purpose across megayears? None of us even existed in anything like our present forms so long ago.”

BUT, Cassiopeia said slowly, WE MUST TRY.