2312

Each terrarium functions as an island park for the animals inside it. Ascensions cause hybridization and ultimately new species. The more traditional biomes conserve species that on Earth are radically endangered or extinct in the wild. Some terraria even look like zoos; more are purely wilderness refugia; and most mix parkland and human spaces in patterned habitat corridors that maximize the life of the biome as a whole. As such, these spaces are already crucial to humanity and the Earth. And there are also the heavily agricultural terraria, farmworlds devoted to producing what has become a very large percentage of the food feeding the people of Earth.

These facts are worth noting and enjoying. We cook up our little bubble worlds for our own pleasure, the way you would cook a meal, or build something, or grow a garden-but it’s also a new thing in history, and the heart of the Accelerando. I can’t recommend it too highly! The initial investment is nontrivial, but there are still many unclaimed asteroids out there.

WAHRAM AND SWAN

Although no doubt they were simply the result of an engineering response to an engineering problem, regarded as an aesthetic matter the Mercurial launching gyres were interesting. A maglev tube twisted in a cone set on its point, increasing in size as it rose. The tip of the cone was secured to a platform that moved in a circle, about the size of the widest part of the cone. The movement of the platform exaggerated very effectively the force of acceleration on the ferries as they were being magnetically thrown up the tube. Thus the ferry they were in had them seated sideways to the ground, but as it careened around and up, their floor became most definitely down, and then with dizzying speed they were launched into space, going so fast that if there had been an atmosphere they would have burned to a crisp the moment they left the tube. The effect as seen from the spaceport resembled some kind of antique carnival ride. From inside the ferry it proved to be a quite serious acceleration, very near the maximum allowed in commercial travel, which was 3.5 g.

Swan Er Hong had strapped herself into the seat beside Wahram just before takeoff, grimacing apologetically at the cliche of her lateness. Now she leaned toward him to look out the little window at the rapidly receding craterscape of her home world. Quickly the land changed from a plane to a ball, a thin crescent of it bathed in sunlight, the gibbous nightside black. Mercury was an interesting place, but Wahram was not unhappy to leave; despite the locals’ best efforts to spruce it up with art, the landscape was a cindery clinker. And the truth was that when he was inside its marvelous gliding city, the sudden blink of illumination on high points to the west always reminded him of the sun, following them relentlessly, always about to burst over the horizon and torch everything.

Their ferry was going to catch the terrarium Alfred Wegener, which was moving so fast that the ferry would have to make another long three-g burn to catch up. During this time, Wahram shifted his seat into bed mode and endured like everyone else. Across the room Swan groaned and curled around herself on her bed. Wahram forbade himself to think about the studies that had been made on the effect of g-forces on the human brain, delicate goo that it was, trapped without much padding inside its hard prison walls. Then the Wegener caught them and reeled them in with a final little squish of g, as if to emphasize the problem.

After that Wahram and the other passengers had to adjust to the sudden weightlessness, and pull themselves from the ferry into the terrarium’s dock, then through the neck and down broad padded stairs to the cylinder floor.