Deep Time. Ian Douglas

metropolis that stretched from the tiny equatorial island of Pulau Lingga, 150 kilometers northwest to Singapore, south to Sumatra, and covered the surface of the sea in between.

      The Americans were on a highly inclined orbit, one that had swung southeast from above France to just brush the southern tip of the Indian subcontinent, and then bypass the Singapore space elevator a couple of thousand miles south of the equator. Even from a distance of 2,000 kilometers, though, the elevator was a spectacular sight, gleaming in the midday sun overhead.

      “Confirm we have clearance to accelerate,” Mackey said over the tactical channel, “Boosting in five … and four … three … two … one … punch it!”

      And the Singapore elevator and the city at its foot vanished, wiped away as the four fighters switched on their forward gravitic projectors and accelerated outbound at seventy thousand gravities. After one second, the Starblades were moving at 700 kilometers per second, and had already traveled 350 kilometers out from Earth. After one minute of steady acceleration, their speed had increased to 42,000 kilometers per second, and they’d covered 1.26 million kilometers—well over three times the distance of the moon from the Earth. Aft, Connor could see the Earth and moon together, a pair of full-lit disks already rendered small by distance, and swiftly growing smaller with each passing second.

      Ahead, and just to starboard, the sun grew visibly larger moment by moment.

      “Hey, Skipper?” Connor called. “I don’t think we’re going to catch them.”

      “We follow orders, Lieutenant.”

      “Yeah … but they’re going to be pushing c in one more minute. And we won’t be there for another six.”

      “Just follow your orders, Lieutenant. There’s nothing else we can do.”

      Charlie One was boosting at fifty thousand gravities, about the same as a Krait ship-to-ship missile. Quite possibly, it was limiting its boost to accommodate its Todtadler escorts, which had an upper limit of fifty thousand Gs.

      Regardless, the problem was one of straightforward TDA mathematics—time, distance, and acceleration. When Charlie One and its Confederation escorts reached about 99.7 percent of the speed of light in another sixty seconds, they would be 63.9 million kilometers from Earth. When the Black Demons reached that same speed in another six minutes, they would be 89.4 million kilometers from Earth—six-tenths the distance between the Earth and the Sun.

      But by that point, Charlie One would have been traveling at near-c for five full minutes, covering an additional 90 million kilometers, for a total of nearly 154 million kilometers.

      In other words, both hunter and prey would be traveling at the same speed, but the hunters would still be almost 65 million kilometers behind Charlie One.

      An ancient sailing aphorism held that a stern chase was a long chase, but it was worse than that—a lot worse. There simply was no way to close that gap. No matter how high the acceleration, the dead hand of Einstein had long ago decreed that there was no way for material objects to pass—or even reach—the speed of light. According to the math governing relativistic calculations, the faster a ship went, the more massive it became, the shorter it became along its line of travel, and the more energy was required to accelerate it, a kind of feedback effect that led to the ship acquiring infinite mass and zero length at the speed of light, thus requiring infinite energy to move it faster.

      The way the universe had been put together, it simply couldn’t be done. Even with all the energy available from the vacuum, the fighters might shave a few more decimals from that 99.7 percent of c, but they could never reach c, never mind surpass it.

      But there was a loophole. Interstellar travel in anything less than decades would not have been possible without it. The Alcubierre Drive had been developed 284 years earlier, a realization of principles first described by physicist Miguel Alcubierre in 1994. Using the same projected singularity technology, an Alcubierre Drive ship pulled itself into an enclosed bubble of spacetime. There was nothing in physics that said that such a bubble couldn’t travel faster than light; indeed, in the earliest instants after the big bang, during the inflationary epoch, space itself had increased in volume by an estimated 10⁷⁸ times in 10^-30 seconds—which meant that points within that expanding volume would be moving away from one another at many, many times the speed of light. A starship imbedded inside that spacetime bubble would be motionless relative to the space immediately around it, and therefore would not violate the ultimate-speed law of the cosmos.

      Alcubierre Drive had several key limitations, though. For one, a ship was effectively “alongside space,” and therefore unable to communicate or interact with anyone in “real space” until it emerged. Another—and the one Connor was focusing on at the moment—was that a ship needed a fairly flat gravitational metric when the drive was engaged. Shipbuilders had been working on that problem for centuries, with no discernable results. So a ship still couldn’t go into faster-than-light drive until it was eight to ten AUs out from a star of Sol’s mass—the distance, roughly, of Saturn at its farthest from Earth.

      No, the real problem was that none of this necessarily applied to Charlie One. It was an alien ship, of unknown potential and technologies. For all any human knew, it might pop into Alcubierre Drive in the next few seconds, or within a couple of million kilometers of the sun. Connor decided, however, that that was extremely unlikely. If they could have done it inside of one astronomical unit, they would have done it by now. The fact that they hadn’t led Connor to speculate that they were aiming for a particular patch of sky, that they would continue accelerating past Sol and out into the outer system before engaging their FTL drive.

       So the million-dollar question is, just what part of the sky might that be?

      It was simple enough to superimpose a star chart over her fighter’s navigational data.

      And the answer to her question was … surprising.

       Chapter Four

       29 June, 2425

       Emergency Presidential Command Post

       Toronto

       United States of North America

       0044 hours, EST

      “The fighters are in pursuit, sir,” Admiral Armitage told Koenig. “They won’t catch the damned thing, though. Not unless either Charlie starts decelerating or they can shave another tenth of a percent off their velocity.”

      “How good are the new designs at that sort of thing?”

      “Mostly depends on the pilot,” Armitage said. “Things are happening awfully fast at those velocities, remember.”

      Koenig nodded. He’d been a fighter pilot once, a very long time ago. “I do.”

      As a fighter moved faster and faster, relativistic phenomena not only increased the vehicle’s mass, pushing it toward an impossible-to-reach infinity, but it also shortened the rate at which time—as measured by an outside observer—passed for the pilot, an effect called time dilation. The pilot experienced everything—the increase in mass, the compression of time—as perfectly normal; it was outside observers that saw basic constants of the universe shift and flow like water.

      For fighters traveling at 99.7 percent of the speed of light, one minute objective—a minute as perceived by slowpoke left-behinds—was only 4.64 seconds. To observers back on board the carrier, the pilot would seem to be moving and speaking and living with extreme slowness.

      The difference could be significant—and a real problem, especially in combat. Where a relatively stationary target had a minute to react to oncoming fighters, those fighters had only a few seconds. The best cybernetically augmented reaction times