Stephen Baxter - Ark

“I won’t let it happen again.”

He nodded. “Good answer.”

“I’ve got my assignment.” She dug her handheld out of her bag, and tried to show him her study of the ecological disaster unfolding up in the Rockies, of how the tree line had already ascended so far that the old regions of montane forest and shrubland, with their ponderosa pines and cactuses, were withering, whole ecozones disappearing.

But Harry waved that away. “You’ve both made yourselves late for Dr. Zheng’s class, haven’t you? Pop quiz.”

Zane fretted, and shuffled from one foot to another. “Can’t we just go to class? A quiz will make us even later.”

“Then you’ll just have to make up that much more work, won’t you? OK. Overnight the Ark executive announced they’ve finally made their decision on where to locate the space launch center-at Gunnison, Colorado. Why there?”

Holle glanced at Zane. “I didn’t know about Gunnison. I listened to the news. But it wasn’t in the bulletin I saw-”

Harry said, “Of course not. You know as well as I do about the secrecy around the project. You can’t keep a space center under wraps, and there will be an official announcement later today. But both your fathers are at the center of the project. You both are. You should know everything they know.” He dug into the pile of books on the trolley, found an atlas, and threw it at Holle; it was a big, heavy, pre-flood volume, and she had trouble catching hold of it. “Why Gunnison? Work it out. I’ll give you five minutes. Otherwise, another question.” And he walked away, towing his trolley.

The two of them kneeled on the floor and spread out the atlas, looking for the right map. “What an asshole,” Holle murmured.

“He’s our pastoral tutor,” Zane said. “Looking after our overall personal development, while the specialist teachers-hey, look, here it is. Colorado.”

They peered at the map, a splash of yellow and green laced across with roads marked in orange and blue. Denver showed up as a knot of development where major highways intersected. The map was pre-flood, but the shoreline of the great inland sea that had washed across the eastern United States, now reaching as far as a line from the Dakotas down to the Gulf, was still too far east to have shown up on this map.

Zane looked at her doubtfully. “So why would you build a space center in Colorado at all?”

“The government would need to keep it close to Denver to make sure it was safe.” Her father talked this sort of thing through with her. As the flood bit away at the remaining land area, more roads and rail routes were cut, more people joined the homeless throngs that washed back and forth across the high ground, and the government’s political control was weakening. The news bulletins were full of growing tension over a would-be separatist Mormon state in Utah; there was even talk of war. “Somewhere in Colorado. But where?”

“High up enough that it won’t flood before 2040.”

“But that still leaves a lot of choice.” She thought about where Cape Canaveral had been situated-on the Atlantic shore, the eastern coastline of America. Why there? For safety reasons, she remembered. You always launched rockets eastward, to get a boost from Earth’s own rotation. Launching from Canaveral had meant that any failure would result in a rocket, flying east, falling harmlessly into the sea. Now the same principle surely applied. “Look,” she said, stabbing a finger at the map. “Gunnison. Twenty-three hundred meters above the old sea level. In 2040 it will be close to the eastern coast of the surviving land. A safe place to launch east.” What else? She dug her handheld out of her bag and quickly interrogated it. “The town’s on a valley bottom, so plenty of flatland. There’s an airport nearby, so you have transport links, and this reservoir, the Blue Mesa, can provide water. And it’s a college town, so there’s a population of workers already in place-”

Harry Smith approached them. “Actually that took you only four minutes. Yes, that’s why Gunnison, Colorado, is going to host the world’s latest, and maybe last, space launch facility. Twenty years ago you’d never have believed it. Good bit of deduction, Ms. Groundwater. OK, you’re free to go.”

They got to their feet, handed back the atlas, and ran for the stairs.

“And, Ms. Groundwater- don’t be late again. Next time you might find somebody else sitting in your seat…”

When they got to the classroom, in the back of a large, emptied-out chamber labeled “Edge of the Wild” on the museum’s second floor, Liu Zheng was in full flow. He stood before an interactive whiteboard, rapidly assembling and erasing graphics, and allowing annotated equations to scroll by. “The essence of an Alcubierre warp bubble is simple,” he said. “Conceptually at any rate. You have an isolated region of spacetime.” This was marked as a circle on his two-dimensional diagrams, but he mimed a sphere with closed hands. “Your spaceship is in this zone here…”

As he talked, a dozen kids all about Holle’s age sat at tables before him, and worked at handhelds and laptops, muttering and murmuring in pairs and threes. Zane led Holle to an empty table. As she passed, the students glanced at her indifferently and looked away.

Holle recognized a few of the kids in here, including Kelly Kenzie, a friend or maybe rival since they were little. Kelly was locked in intense conversation with a red-haired boy who looked a bit older. There were Cora Robles and Susan Frasier working in a huddle, two bright, pretty girls together. And Thomas Windrup and Elle Strekalov, sitting so close they might have been conjoined twins, as they had been all the way through grade school. Elle was a lot better-looking than Thomas, and the class gossips didn’t know why they stayed together. There was a lot of noise in here, and among the noisiest were Joe Antoniadi and Mike Wetherbee. Joe, an Italian-American whose family had fled New York, was likable, friendly, easy to impress. Even as Zheng talked, Mike was cracking jokes in his broad Australian accent and making Joe laugh. Mike’s family were refugees from an almost entirely abandoned continent.

They reached their table. Zane had a laptop, and Holle dug her handheld out of her bag.

If the students had been indifferent to Holle, Liu Zheng didn’t so much as register her presence. He just carried on with what he was saying. “So how do you fly to the stars? Well, you engineer the space-time metric. You arrange it for spacetime to expand behind you, mimicking the inflationary conditions of the early universe. And you make spacetime collapse ahead of you, mimicking a black hole, say. Thus your spacetime bubble is pulled and pushed, driven ahead across the manifold. You are riding a propagating wave in spacetime.”

“Like surfing!”

“Yes, Mr. Meisel. Though I myself have never surfed.”

Holle thought she understood. The spacecraft would be embedded in spacetime like a toy insect in a block of glass. You didn’t transport the ship itself, but a whole chunk of the spacetime around it.

“This is the essence of the warp bubble. The transported spacetime must be large enough to keep you away from the regions of heavy curvature associated with the warp bubble itself-which would manifest, of course, like strong gravity fields. But what of travel faster than light? Einstein tells us that it is impossible to move faster than light-speed as measured against local landmarks. ” He emphasized the words heavily. “The trick is to carry those landmarks with you. The ship itself is not traveling at all relative to the spacetime bubble around it. It is the bubble itself that propagates at multiples of light speed, as desired. You are not traveling faster than light, because you are carrying the light with you…”