Other Worlds Than These

And just maybe, to find whatever made the focal point. Somewhere near the dawn line.

They came arcing over the Counter-night. A darkness deeper than she had ever seen crept across Counter. Night here, without the shrunken Moon’s glow, had no planets dotting the sky, only the distant sharp stars. At the terminator shadows stretched, jagged black profiles of the ridgelines torn by pressure from the ice. The warming had somehow shoved fresh peaks into the gathering atmosphere, ragged and sharp. Since there was atmosphere thicker and denser than anybody had expected the stars were not unwinking points; they flickered and glittered as on crisp nights at high altitudes on Earth. Near the magnetic poles, she watched swirling blue auroral glows cloak the plains where fogs rose even at night.

A cold dark world a universe away from sunny Earth, through a higher dimension…

She did not really follow the theory; she was an astronaut. It was hard enough to comprehend the mathematical guys when they spoke English. For them, the whole universe was a sheet of space-time, called “brane” for membrane. And there were other branes, spaced out along an unseen dimension. Only gravity penetrated between these sheets. All other fields, which meant all mass and light, was stuck to the branes.

Okay, but what of it? had been her first response.

Just mathematics, until the physics guys—it was nearly always guys—found that another brane was only twenty-two centimeters away. Not in any direction you could see, but along a new dimension. The other brane had been there all along, with its own mass and light, but in a dimension nobody could see. Okay, maybe the mystics, but that was it.

And between the two branes only gravity acted. So the Counter-Earth followed Earth exactly, and the Counter-Moon likewise. They clumped together, hugging each other with gravity in their unending waltz. Only the Counter-brane had less matter in it, so gravity was weaker there.

Julie had only a cartoon-level understanding of how another universe could live on a brane only twenty-two centimeters away from the universe humans knew. The trick was that those twenty-two centimeters lay along a dimension termed the Q-coordinate. Ordinary forces couldn’t leave the brane humans called the universe, or this brane. But gravity could. So when the first big gravitational wave detectors picked up coherent signals from “nearby”—twenty-two centimeters away!—it was just too tempting to the physics guys.

And once they opened the portal into the looking-glass-like Counter-system—she had no idea how, except that it involved lots of magnets—somebody had to go and look. Julie and Al.

It had been a split-second trip, just a few hours ago. In quick flash-images she had seen: purple-green limbs and folds, oozing into glassy struts—elongating, then splitting into red smoke. Leathery oblongs and polyhedrons folded over each other. Twinkling, jarring slices of hard actinic light poked through them. And it all moved as though blurred by slices of time into a jostling hurry—

Enough. Concentrate on your descent trajectory.

“Stuff moving down there,” Al said.

“Right where the focal point is?” At the dawn’s ruby glow.

“Looks like.” He close-upped the scene.

Below, a long ice ridge rose out of the sea like a great gray reef. Following its Earthly analogy, it teemed with life. Quilted patches of vivid blue-green and carrot-orange spattered its natural pallor. Out of those patches spindly trunks stretched toward the midmorning sun. At their tips crackled bright blue St. Elmo’s fire. Violet-tinged flying wings swooped lazily in and out among them to feed. Some, already filled, alighted at the shoreline and folded themselves, waiting with their flat heads cocked at angles.

The sky, even at Counter’s midmorning, remained a dark backdrop for gauzy auroral curtains that bristled with energy. This world had an atmospheric blanket not dense enough to scatter the wan sunlight. For on this brane, the sun itself had less mass, too.

She peered down. She was pilot, but a biologist as well. And they knew there was something waiting…

“Going in,” she said.

Into this slow world they came with a high roar. Wings flapped away from the noise. A giant filled the sky.

Julie dropped the lander closer. Her legs were cramped from the small pilot chair and she bounced with the rattling boom of atmospheric braking.

She blinked, suddenly alarmed. Beside her in his acceleration couch Al peered forward at the swiftly looming landscape. “How’s that spot?” He jabbed a finger tensely at the approaching horizon.

“Near the sea? Sure. Plenty of life forms there. Kind of like an African watering hole.” Analogies were all she had to go on here but there was a resemblance. Their reconn scans had showed a ferment all along the shoreline.

Al brought them down steady above a rocky plateau. Their drive ran red-hot.

Now here was a problem nobody on the mission team, for all their contingency planning, had foreseen. Their deceleration plume was bound to incinerate many of the life forms in this utterly cold ecosystem. Even after hours, the lander might be too hot for any life to approach, not to mention scalding them when nearby ices suddenly boiled away.

Well, nothing to do about it now.

“Fifty meters and holding.” Al glanced at her. “Ok?”

“Touchdown,” she said, and they settled onto the rock.

To land on ice would have sunk them hip-deep in fluid, only to then be refrozen rigidly into place. They eagerly watched the plain. Something hurried away at the horizon, which did not look more than a kilometer away.

“Look at those lichen,” she said eagerly. “In so skimpy an energy environment, how can there be so many of them?”

“We’re going to be hot for an hour, easy,” Al said, his calm, careful gaze sweeping the view systematically. The ship’s computers were taking digital photographs automatically, getting a good map. “I say we take a walk.”

She tapped a key, giving herself a voice channel, reciting her ID opening without thinking. “Okay, now the good stuff. As we agreed, I am adding my own verbal comments to the data I just sent you.”

They had not agreed, not at all. Many of the Counter Mission Control engineers, wedded to their mathematical slang and NASA’s jawbone acronyms, felt that commentary was subjective and useless. Let the expert teams back home interpret the data. But the PR people liked anything they could use.

“Counter is a much livelier place than we ever imagined. There’s weather, for one thing—a product of the planet’s six-day rotation and the mysterious heating. Turns out the melting and freezing point of methane is crucial. With the heating-up, the mean temperature is well high enough that nitrogen and argon stay gaseous, giving Counter its thin atmosphere. Of course, the ammonia and carbon dioxide are solid as rock—Counter’s warmer, but still incredibly cold, by our standards. Methane, though, can go either way. It thaws, every morning. Even better, the methane doesn’t just sublime—nope, it melts. Then it freezes at night.”

Now the dawn line was creeping at its achingly slow pace over a ridgeline, casting long shadows that pointed like arrows across a great rock plain. There was something there she could scarcely believe, hard to make out even from their thousand-kilometer-high orbit under the best magnification. Something they weren’t going to believe back Earthside. So keep up the patter and lead them to it. Just do it.

“Meanwhile on the dark side there’s a great ‘heat sink,’ like the one over Antarctica on Earth. It moves slowly across the planet as it turns, radiating heat into space and pressing down a column of cold air—I mean, of even colder air. From its lowest, coldest point, winds flow out toward the day side. At the sunset line they meet sun-warmed air—and it snows. Snow! Maybe I should take up skiing, huh?”

At least Al laughed. It was hard, talking to a mute audience. And she was getting jittery. She took a hit of the thick, jolting Columbian coffee in her mug. Onward—

“On the sunrise side they meet sunlight and melting methane ice, and it rains. Gloomy dawn. Permanent, moving around the planet like a veil.”

She close-upped the dawn line and there it was, a great gray curtain descending, marching ever-westward at about the speed of a fast car.

“So we’ve got a perpetual storm front moving at the edge of the night side, and another that travels with the sunrise.”