by Ian Douglas
An interesting thought. Gray had participated in other temporal jumps using the TRGA cylinder network stretched across parts of the galaxy, but those had been such large jumps that temporal paradox didn’t appear to play a part. In particular, the star carrier America and other USNA ships had jumped into the N’gai Cluster some 876 million years in the past, at a time just before a dwarf galaxy occupied by a multi-species associative called the Sh’daar Empire had been devoured by the Milky Way. Arguably, those visits to the remote past could have—perhaps should have—changed the unfolding course of history, but there was no indication that this was the case. Possibly—or so the theory went—temporal shifts and paradoxes were blurred out by the passage of enough time. Eight hundred million years ago, life on Earth was limited to single-celled microbes adrift in primitive seas. Events within the N’gai Cluster just above the plane of the Milky Way would be smeared away into oblivion by the passage of the eons.
But a time-jump of just a month or so meant that any possible changes would take place within the lifetime of the people involved. It meant that . . . had Earth been destroyed and the president killed yesterday, somehow that other reality would have ceased to exist, would have been wiped away as if it had never been.
Or, looked at another way, that alternate history was now inaccessible. As Gray understood the quantum physics behind it, when the Republic had changed history, she had, in effect, created a new universe, a new continuity branching off from the original. The original universe leading off from the moment of Koenig’s death might still exist . . . elsewhere, elsewhen, somewhere else in the multiverse, but it was no longer reachable from this newly amended version of Gray’s universe.
The implications could make your head ache. No wonder the Sh’daar had been terrified of temporal paradoxes.
So had the Harvesters sent the Republic back through time expressly to stop the Rosetters? Had they known what was happening, what would happen in exquisite detail enough to fine tune them to that degree?
There was no way to be sure.
And—a second nagging thought followed close on the heels of the first—maybe that very uncertainty was deliberate. The Harvesters might have used the Republic as a tool to change events on and near Earth, but in a way that would leave humans unsure of whether the Deneban intelligence had changed things.
That was the trouble with dealing with gods. You never knew if even the most random and minor events were simply coincidence . . . or part of some vast plot or cosmic rewrite of Reality.
Well . . . it did keep life . . . interesting.
Vasilyeva was still speaking.
“When the Rosette entity cloud vanished from the Sol System yesterday, it was traveling in the direction of the constellation Centaurus at some ninety percent of the speed of light. Although we can’t know for sure until our deep-space intelligence resources at Omega Centauri can report back to us, we believe that the Rosette entity would have made its way here . . . the globular star cluster of Omega Centauri.”
The cluster appeared on-screen, looking to Gray’s mind like a tightly packed ball of popcorn. “The largest globular cluster associated with our galaxy,” Vasilyeva said, “ten million stars crowded into a flattened sphere just two hundred thirty light years across, lying just under sixteen thousand light years from Earth.”
The image on the screen behind her shifted again, this time showing a scene recorded by the star carrier America a year ago—a view of the fast-orbiting sextet of black holes at the heart of Omega Centauri. Around and beyond those spinning singularities shone the pale translucence of the Rosette entity’s tinkerings with local spacetime, ghostly geometric structures seemingly molded from glowing aurorae. Beyond that, the sky was a solid wall of brilliant stars, most brighter than Venus as seen from Earth.
“The so-called Black Rosette presents cosmologists with a number of mysteries,” Vasilyeva continued. “First though . . . what we know . . . or think we know.
“We know that whoever engineered the structure intended to use it as a kind of super-massive stargate . . . similar to the far smaller TRGA cylinders. Six black holes, each about forty solar masses—a total of some two hundred forty solar masses—rotating about a common center at a velocity in excess of zero-point-zero eight c, or about twenty-six thousand kilometers per second. Such masses and velocities disrupt local spacetime, creating gateways . . . alternate pathways . . . that reach into remote parts of this universe or, possibly, across vast reaches of time. It has been hypothesized that the Rosette entity entered this universe through an opening leading here from some other universe entirely.”
As she spoke, the scanner panned across the face of the rotating structure—world-sized blurs enmeshed in a haze of blue-violet plasma. At the center of the Rosette, alternate starfields appeared and precessed with the movement of the cameras, one following another as the camera angles changed. Most of the starfields appeared . . . normal, whatever that meant within such an alien context, though each starfield was different. A few looked out into seething chaos of raw energy . . . or into a vast and lightless Void.
“Each vista is a different space,” she said. “Possibly each represents a different time, a different epoch. Some . . .”
She accessed some in-head control, and the camera image blurred . . . then shifted to a single motionless image. “Some,” she continued, “have actually been identified.”
The frozen image looked through the Rosette Gateway into the heart of a densely packed star cluster, but clearly one somewhat different from Omega Centauri in its mix of old red and young blue-white stars. To Gray, it appeared eerily familiar.
He grappled with the memory . . . and then he had it.
The alien heart of the N’gai Cluster.
“It took us a long time, studying the images of the Rosette returned to us by the Endeavor, the America, and others, to identify this one pathway. What we’re seeing here is an open gate into the N’gai Cluster, a dwarf galaxy cannibalized by our own Milky Way approximately half a billion years ago. Our ships have accessed the N’gai spacetime using TRGA cylinders, contacting the Sh’daar culture there approximately eight hundred million years ago.
“What is of particular interest, of course, is that we have known for some centuries now that the globular star cluster we call Omega Centauri is, in fact, a remnant of a dwarf galaxy assimilated by the Milky Way in the remote past. The nearby sun Kapteyn’s Star, with the gas giant Bifrost and its once-habitable moon Heimdall, has been identified as a former member of that cluster.
“Within the N’gai galaxy eight hundred seventy-six million years ago . . .”
The scene shifted to show an image recorded by the America within the Sh’daar Associative. In the distance, a tiny, perfect ring of intolerably brilliant blue-white stars hung against a far vaster, cavernous expanse of bright stars.
“Note the obviously artificial asterism,” she said. “Six young, blue-white stars, each of roughly forty solar masses. At some point after America visited N’gai, these stars must have exploded, creating the ring of black holes we call the Black Rosette in today’s Omega Centauri.
“In other words, Omega Centauri and the N’gai Dwarf Galaxy are the exact same place, separated by a mere eight hundred and some million years.”
That bald statement raised some chuckles throughout the audience, and Gray gave a wry shake of his head. Eight hundred million years ago, life evolving in Earth’s oceans had only just decided that sex was a pretty good idea. Calling that gulf of eons mere bordered on the absurd.
The screen behind Vasilyeva returned to the present, six black holes circling a shifting starscape.
“So . . . first mystery,” she said. “Who created the portal? The Rosette entity? Clearly, no. We know that the Rosette was already here long before the Rosette entity came through from somewhere else . . . and we are reasonably certain that it was created by the simultaneous destruction of the six blue-white giant suns within the N’gai Cluster, eight hundred sev
enty-six million years in the past. So . . . the Sh’daar? Unlikely. Six supernovae detonating simultaneously within the center of their polity would be devastating, possibly suicidal. The Sh’daar themselves are evasive when asked about the Six Suns’ origin. We think it possible that they moved the Six Suns into position, and that they continue to feed them hydrogen plasma to renew them as they begin to age. At some point after the Sh’daar epoch at N’gai, they may have used the Six Suns to escape their galaxy and enter ours. To do so, they might have detonated the Six Suns. Or . . . they abandoned the N’gai Cluster by other means, the Six Suns evolved normally, and turned into black holes on their own within a few hundred million years. Blue-white giants of around forty solar masses, remember, have life spans of only a very few hundred million years at best.
“But this leads us to the next mystery . . . arguably the biggest one. The six black holes of the Rosette cannot be natural objects.”
That got Gray’s attention. Clearly the arrangement of the Six Suns—and, subsequently, the Black Rosette—was artificial, its structure, its balance created by some intelligence with the technological ability to move giant stars around like marbles. But Vasilyeva clearly was referring to something else.
“Take a body with the mass of the moon and compress it into a black hole,” she said. “You get a micro-black hole with a diameter of roughly a tenth of a millimeter, smaller than a speck of dust.
“Take a larger body, one with a mass equivalent to that of the Earth and compress it down to a black hole. You get a black hole with a diameter of about a centimeter. Everybody with me? When I say diameter, by the way, I’m referring to twice the object’s Schwarzschild radius, which defines the event horizon. The diameter of a black hole, following the curve of spacetime inside, would technically be infinite.
“Okay, more mass, larger diameter. But when one of those forty-solar-mass stars from the Six Suns collapses into a singularity, it should form a black hole with a diameter of several hundred kilometers—let’s say three hundred. However, each of the black holes of the Black Rosette has an apparent diameter of about fifteen thousand kilometers, slightly larger than the Earth.
“This would seem to be a violation of what we know to be the laws of physics. The Black Rosette objects are each five times larger than they should be. And we do not understand how this could possibly be the case.”
Gray blinked, then swiftly consulted a local data library through his in-head software. Damn, the woman was right. A star with a mass of forty Suns was still only a stellar-mass black hole, as opposed to an intermediate one with a mass of one thousand to a hundred thousand times that of Sol. It would collapse into a black hole with an event horizon diameter of somewhere between 200 and 300 kilometers . . . or maybe a bit more depending on a number of variables.
“Our astrophysicists have been studying the problem,” Vasilyeva went on. “One possibility is that these objects are not true black holes—that is, gravitational singularities surrounded by event horizons—but something even more exotic called black stars. It used to be thought that some lower limit in possible size might stop a black hole’s mass from collapsing all the way to infinity; the Planck length as a lower limit of definition for space, for example, might stop the collapse at a larger diameter than the math suggests. We still don’t know what it is that could block the collapse in this manner, however.
“Another possibility is that the Black Rosette objects have received a lot of additional mass over the eons, and that mass is somehow being distributed across several linked locations . . . other universes, for instance. Until we can park ourselves there and study the phenomenon further, however, we are not going to be able to unravel this particular mystery.
“Both the Moskva Byuro Vnezemnoy Tekhnologii and the Ministère de l’Intelligence Extraterrestre are on record now as recommending that we assemble a military force of sufficient strength to pursue the Rosette entity back to the core of Omega Centauri. There we either force peace with the entity, or we secure a position in front of the Black Rosette and hold it long enough to complete certain key studies. Your own Konstantin has suggested that a dual approach to the objective might be the way to go. One approach through normal space . . . a second through time.
“I gather we have already begun assembling the fleet to accomplish this. To discuss this somewhat novel approach to naval tactics, I give you the president’s chief of staff, Admiral Eugene Armitage.”
A smattering of applause followed Admiral Armitage up to the podium. Gray had met him before, usually in President Koenig’s office. He was smart and tough and seemed to know what he was doing.
At the moment, however, he looked uncertain.
“Thank you, ladies and gentlemen . . . Mr. President. And thank you Dr. Vasilyeva for more information about the Black Rosette than I ever cared to know.”
Several in the audience laughed, and Vasilyeva smiled and shrugged.
“As Dr. Vasilyeva intimated, we are already assembling not one, but two strike fleets comprising heavy warships from all over Earth. This will be a truly international expedition, one representing all of Humankind. Our goal will be to force peace with the recently departed Rosetters. To accomplish this, we intend to employ a two-pronged attack, one through normal spacetime . . . and the second through time, from a way point located eight hundred million years in the past.”
Gray abruptly saw the plan with icy clarity. The fleet approaching through normal space, of course, would be seen by the Rosetters, its progress through normal space followed—at least from the nearby TRGA that humans used to reach Omega Centauri. The super-AI that was the entity—the Consciousness, as it seemed to call itself by some reports—held an utterly staggering superiority in technology and in available energy, plus the ability to bend and reshape time itself, and would have little difficulty in annihilating the normal-spacetime fleet.
But a second fleet could travel through the TRGA network back in time to the Sh’daar Associative, eight hundred million years in the past. They would approach the Six Suns, in the core of the N’gai Cluster, align themselves on one particular meticulously calculated path of approach, and accelerate . . . slamming themselves through the gateway, emerging from the spinning wheel of the Black Rosette into the time they’d left.
The Consciousness, fixed on the normal-spacetime fleet, would not see them coming.
What kind of damage the surprise cross-time strike might be able to inflict was an unknown. But Gray knew that the maneuver would give them their single chance of success.
He also knew now why Koenig had given him back his rank and uniform.
He would be leading the strike across the gulfs of time.
Chapter Twenty
5 March 2426
TC/USNA CVS America
N’gai Cloud, Omega T-0.876gy
1245 hours, TFT
The cavernous inner reaches of the N’gai Cloud hadn’t changed much since he’d seen it last, so far as Gray could tell. Emerging from the TRGA cylinder that had brought them on this, the penultimate jump across space and time, the America and eighty-seven other human vessels decelerated into the cloud’s central core. Ahead, made tiny by distance, six brilliant pinpoints described a circle—visible from this angle as a narrow ellipse—the Six Suns.
My God, it’s good to be back, he thought. Not back in the N’gai Cloud, of course . . . but back on board the America. It was as though no time had passed at all, and that thought brought a wry grin to his face. For the America, trapped within the Rosetters’ time-slowing field, that statement was very nearly literally true.
Their departure from Earth had been somewhat delayed by the need to gather in as many ships as possible, including several dozen that had returned to Earth from other star systems. The Marine carrier Guadalcanal had joined them just before they’d boosted for the first TRGA way point—Captain Laurie Taggart in command. He hadn’t had a chance to see her yet, and hoped a visit could be arranged.
But . . . first thin
gs first.
With all members of Battlegroup America reporting in after the transit of the final TRGA cylinder, he gave the command to begin moving slowly into the N’gai Cloud’s inner sanctums. Millions of stars crowded one another in a searing white blaze of light.
“Give us a continuity check,” he ordered. “What the hell time is it?”
“We’ve established communications with a TRGA picket vessel, sir,” Commander Benedict, the comm officer of the watch, reported. “The Xuzhou . . . Captain Cheung.” The Xuzhou was a Chinese frigate, one of a dozen smaller vessels stationed here in the Cloud on a rotating basis. There was a brief wait as America exchanged data with the Xuzhou. “We’re good, Admiral,” Benedict reported at last. “Local fleet time is twelve hundred forty-five hours, five March. No overlap, no paradox.”
That, more than anything else, was the problem with jumping across hundreds of millions of years . . . the terror that they would emerge from a TRGA jump too early on the local time line. Meeting an earlier version of yourself, for instance, when you knew you’d not run into your future self the last time you were here . . . thinking about that sort of thing could keep you up at night. The timelike paths described within the lumens of the TRGA cylinders, though, appeared to take that into account; time flowed steadily forward on either side of the TRGA, so that a minute passed there meant that a minute passed here.
“Thank God,” Captain Gutierrez said, a heartfelt exhalation.
“Did you have any doubts, Sara?” Gray asked her in-head, grinning.
“I always have doubts, Admiral.”
“With time travel . . . yeah, I can understand that. Sometimes you just can’t tell whether you’re coming or going.”
Despite his casual demeanor, Gray felt an inward, trembling relief as well. Theoretically, a tiny alteration of the timelike path a ship took through a TRGA would alter the time at which you emerged, as well as the space. Cosmologists were still wrestling with the details back home, but Gray couldn’t help but worry that someday he was going to provide them with some unfortunate data about the dangers of time travel. Something very much like that had happened when Republic had returned to Earth a month early. Gray had the impression that the entire astrophysics world was now holding its collective breath, waiting for any untoward and paradoxical effects to manifest.
