The Long Mars

22

By the end of February, the Armstrong and Cernan had passed Earth West 30,000,000. There was no particular celebration—and nor had there been a few days back, when the ships had passed 20,000,000, and so beaten the five-year-old Chinese record. Not in the public spaces anyhow, at Maggie’s quiet order.

With the sheaf of worlds dominated by crabs and other crustaceans far behind, now they passed through a band of worlds where—as the biologists discovered on scooping up samples of pond scum—not only was there no multicellular life, no animals, no vegetation, there was often no evidence of complex cellular life: that is, no cells with internal nuclei, like those of Maggie Kauffman’s own body. Only the most simple of bacteria dwelled here, in mats and banks.

The crew called these “purple scum worlds’.

Still, in such worlds there could be complexity, of a different sort. They found structures like stromatolites, mounds of bacteria built up layer by layer in the sunlight, mindlessly cooperating in what might on Datum Earth have been called primitive ecosystems. But after billions of years of a different evolution, there was nothing primitive about these structures. Especially not the ones that crept up on an unwary crewman, taking samples with her back turned…

Two days’ flight later, at around Earth West 35,000,000, after millions of scum worlds all more or less identical, they encountered another band of worlds with their own peculiarity. Here oxygen levels in the air were very low, carbon dioxide high. The airships stopped at random on one such world—Earth West 35,693,562. Biologists in oxygen masks cautiously explored the shore of an arid continent. Even by the standards of the “purple scum” worlds, this was an Earth poor in life.

It took some detective work on a larger scale to figure out the cause. Under Gerry Hemingway’s prompting, Maggie authorized the launch of balloons, sounding-rockets, and one of their small stock of precious nanosat launchers, and a global map was assembled. Here, North America had united with most of the world’s other continents, rafts of granite floating on mantle currents, to form a single supercontinent—like the Datum’s Pangaea, Maggie was told, which had broken up a quarter of a billion years back. One huge continent, and nothing else but ocean.

And supercontinent worlds, it turned out—just as the Chinese had found, Maggie discovered, consulting with Wu Yue-Sai—weren’t particular hospitable to life. The continent’s vast interior was worn down and arid; it was like one gigantic Australia, with only the coastal regions showing any kind of fecundity. The expedition pushed on, across one supercontinent world after another—the “Pangaean Belt’, the geographers called it. They saw no sign of life more complex than stromatolites at the coastal fringes, and if some kind of exotic critter roamed the tremendous plains of some footprints of these world continents, well, Maggie was content to leave the discovery to future travellers.

The Pangaean Belt turned out to be about fifteen million worlds thick. Fifteen million: sometimes Maggie struggled to grasp the significance of such numbers. The width of the Pangaeas alone was ten times the stepwise distance between the Datum and Valhalla, for instance, a reasonable measure of the width of the Long Earth as colonized by human beings in the generation since Step Day. Yet, travelling at the airships’ nominal cruise speed, they crossed it in a week.

After the Pangaeas, fifty million worlds from home, they entered yet another purple scum belt, where at least the scattered continents provided varied scenery. The atmospheric and climate conditions were often close enough to the Datum that Maggie could authorize shore leave without significant protective clothing, and her crews of very healthy, mostly very young people could escape from the roomy but confined interiors of the gondolas. But there was nothing to do down there, nothing to see—pond scum didn’t count—and people kind of clowned around aimlessly. There was only so much fun you could get out of lobbing rocks at stromatolites.

Snowy, the beagle, was different, however. Maggie watched him stride alone across the most featureless of landscapes, his extra ordinary animal-human body held erect in the Navy uniform Maggie had had specially tailored for him, his wolf eyes glittering, his head tipped back so his nostrils could drink in the local scents. He seemed to find something of interest in every world they called at. And he kept his own log, a vocal record rigged up for him by Harry Ryan since his people mostly lacked conventional literacy. Maggie promised herself to get that log transcribed and studied. She had the feeling it would describe a voyage perceived quite differently from the human crew’s experience. Which, of course, was why Snowy was here.

She tried to talk to Mac about Snowy, and whatever problem the two of them had. All she got was stony silence, a Mac speciality when he was in the mood.

When Snowy was off the ship Shi-mi would come out of Maggie’s rooms and run around the gondola of the Armstrong, presumably letting off steam in her own way, and submitting to being spoiled a little by the crew. Save for Mac, of course.

They pushed on, thousands upon thousands of steps. Even Jokers seemed sparse out here. Maggie fretted that the journey was turning into a kind of experiment into mass sensory deprivation. An unexpected hazard for a pioneer, she thought.

At first they kept the nominal cruise speed at a little over two million steps a day, achieved by stepping at fifty steps per second for around twelve hours’ run-time per day. Maggie was mindful that she was running two essentially experimental ships here, and Harry Ryan—backed up by his Chinese counterpart Bill Feng with whom, after initial suspicion, he had formed an unlikely buddy-buddy partnership—was resistant to any change to his preplanned test routines. But Maggie pushed Harry to up the running time to eighteen hours a day, enabling a transit rate closer to three million steps daily, rather than two. That still allowed for two hours’ downtime for the engine in the average watch, and she permitted Harry to have one full day per week without any stepping, for tests and overhauls on both boats.

Meanwhile she tried to keep the crews occupied. Luckily the gondolas were big enough to allow room for physical exercise and training, even in flight. She got together with Sergeant Mike McKibben, the commander of the two chalks of marines she had on board the airships, and fixed up joint exercises to keep both contingents happy. She also allowed, with caution, some competitive sports between the two services, Navy versus marines, from squash to Scrabble, McKibben’s surprising pet love.

She did quietly order Nathan to ensure that her crews’ salaries were firewalled so they couldn’t be gambled away on the turn of a high-scoring tile.

“Yes, Captain. Should I warn Mike McKibben to do the same for his guys?”

She grinned. “Let’s see if he thinks of that for himself.”

“Yes, Captain.”

Even at the increased rate, it took nineteen more days before they left behind the purple scum.

Joe Mackenzie, one night towards the end of that interval, revealed to Maggie that he too was keeping a kind of log of the trip.

“My God, Mac, is everybody on these damn ships keeping a diary? We’re like a dysfunctional White House.”

“It’s a solitary habit, but there are worse. And, according to my personal log—you know, it’s hard to grasp the scale of what we’re doing here, because epic stepwise journeys are new, whereas we’ve been making long geographical journeys on Earth since, what? The Vikings, the Polynesians? But even so it seems to me we’re coming up on a milestone, of sorts. Look—when Armstrong flew to the moon, he was undertaking a journey on a scale that dwarfed anything in human history, or indeed prehistory. The distance to the moon, two hundred and forty thousand miles out, is about sixty times the radius of the Earth. OK? Now, Datum to Valhalla is the civilized Long Earth, as much as it’s civilized at all. That’s around one point four million steps. And sixty times that distance, stepwise, is—”

She figured it quickly. “About eighty-four million.”

“Which milestone we’re due to pass tomorrow.” He raised the glass of single malt she’d poured for him. “Whatever comes next for us, in comparison with other human achievements we’ve achieved our personal moon shot, Maggie.”

“I’ll buy that. And a good excuse for a celebration,” she said, always thinking of crew morale. “Let’s round it up to a hundred million. Sounds neater.” She glanced at a calendar. “Looks like we’ll get there on April Fool’s Day.”

“Seems appropriate,” Mac said.

“We’ll have a day’s R&R, make a couple of speeches, take photographs, plant a flag.”

“I was thinking it would be a good place to throw out the cat. But fine, do it your way.”