For their new sun, the crew of the Northern had selected a particular VMO: a Very Massive Object, a star of a thousand Solar masses — a typical member of this alternate cosmos. This star drifted through the halo of a galaxy, outside the galaxy’s main disc. Huge shells of matter — emitted when the star was even younger — surrounded New Sol, expanding from it at close to the speed of light.
The Great Northern itself hovered, a few miles from the pod. By the harsh, colorless light of New Sol Louise could see the bulky outline of the lifedome, with the sleek, dark shape of the Xeelee nightfighter still attached to the dome’s base — and there, still clearly visible, was the hull-scar left by the impact with the strand of cosmic string.
The battered ship orbited the new sun as timidly as ice comets had once circled Sol itself — so widely that each “year” here would last more than a million Earth years. The ship was far enough away that the VMO’s brilliance was diminished by distance to something like Sol’s. But even so, Louise thought, there was no possibility that the VMO could ever be mistaken for a modest G-type star like Sol. The VMO was only ten times the diameter of old Sol, so that from this immense distance the star’s bulk was reduced to a mere point of light — but its photosphere was a hundred times as hot as Sol. The VMO was a dazzling point, hanging in darkness; if she studied it too long the point of light left trails on her bruised retinae.
Externally, the Northern’s lifedome looked much as it had throughout its long and unlikely career: the ship’s lights glowed defiantly against the glare of this new cosmos, and the forest was a splash of Earth-green, flourishing in the filtered light of New Sol. But inside, the Northern had become very different. In the year since its arrival through the Ring, the dome had been transformed into a workshop: a factory for the manufacture of exotic matter and drone scoop ships.
Morrow, beside Louise, was blinking into the light of New Sol. His cupped hand shaded his eyes, the shadows of his fingers sharp on his face. He was frowning and looked pale. He caught Louise’s glance. “Things are certainly different here,” he said wryly.
She smiled. “If we ever build a world here, it won’t have a sun in the sky. Instead, by day there will be this single point source, gleaming like some unending supernova. The shadows will be long and deep… and at night, the sky will shine. It’s going to seem very strange.”
He glanced at her sharply. “Well, it will be strange for those of you who remember Earth, I guess,” he said. “But, frankly, there aren’t so many of you around any more…”
Now the pod’s rotation carried the new sun out of visibility, below the pod’s limited horizon. And — slowly, majestically — the lights of their new galaxy rose over their heads.
This galaxy was a flat elliptical, but would have seemed a dwarf compared to the great galaxies on the other side of the Ring: with a mass of a billion suns, the star system was a mere hundredth the bulk of the Milky Way, or Andromeda, and not much larger than the old Magellanic Clouds, the minor companion galaxies to the Milky Way. And — since the average size of stars here was a hundred times greater than in the Milky Way — there were only ten million stars in this galaxy, compared to the Milky Way’s hundred billion… But every one of those stars was a brilliant white VMO, making this galaxy into a tapestry of piercingly bright points of light. It was like, Louise thought, surveying a field of ten million gems fixed to a bed of velvet.
This universe was crowded with these bland, toy galaxies; they filled space in a random but uniform array, as far as could be seen in all directions. This cosmos was young — too young for the immense, slow, processes of time to have formed the great structures of galactic clusters, superclusters, walls and voids which would one day dominate space.
Morrow stared up uneasily at the soaring form of the galaxy. Apparently unconsciously, he wrapped both hands across his stomach.
“Morrow, are you okay?”
“I’m fine,” he told Louise, unconvincingly. “I guess I’m just a little susceptible to centrifugal force.”
Louise patted his hands. “It’s probably Coriolis, actually — the sideways force. But you shouldn’t let the pod’s rotation bother you,” she said. She thought it over. “In fact, you should welcome your motion sickness.”
Morrow raised his shaven eyebrow ridges. “Really?”
“It’s a sensation that tells you you’re here, Morrow. Embedded in this new universe…”
The laws of physics were expressions of basic symmetries, Louise told him. And symmetries between frames of reference were among the most powerful symmetries there were.
Morrow looked dubious. “What has this to do with space sickness?”
“Well, look: here’s a particular type of symmetry. The pod’s rotating, in the middle of a stationary universe. So you feel centrifugal and Coriolis forces twisting forces. The forces are what is making you uncomfortable. But what about symmetry? Try a thought experiment. Imagine that the pod was stationary, in the middle of a rotating universe.” She raised her hands to the galaxy wheeling above them. “How would you tell the difference? The stars would look the same, moving around the pod.”
“And we’d feel the same spin forces?”
“Yes, we would. You’d feel just as queasy, Morrow.”
“But where would the forces come from?”
She smiled. “That’s the point. They would come from the inertial drag of the rotating universe: a drag exerted by the huge river of stars and galaxies, flowing around you.
“So you shouldn’t be worried by, or embarrassed by, your queasiness. That’s the feeling of your new universe, plucking at you with fingers of inertial drag.”
He smiled weakly, and ran a palm over his bare, sweat sprinkled scalp. “Well, thanks for the thought,” he said. “But somehow it doesn’t make me feel a lot better.”
Spinner-of-Rope and Mark were sitting in the two seats behind Louise and Morrow. Now Mark leaned forward. “Well, it should,” he said. “The fact that general relativity is working here — as, in fact, are all our familiar laws as far as we can tell, to the limits of observation — is the reason we’re still alive, probably.”
Spinner-of-Rope snorted; VMO light gleamed from the arrow head pendant she still wore between her breasts. “Maybe so. But if this universe is so damn similar, I don’t see why it should be so different. If you see what I mean.”
Mark spread his hands, and tilted his head back to look at the dwarf galaxy. “The only real difference, Spinner, is one of point of view. It’s all a question of when.”
Spinner frowned. “What do you mean, ‘when’?” Behind her spectacles Spinner’s small, round face seemed set, intent on the conversation, but Louise noticed how her hands tugged at each other endlessly, like small animals wriggling in her lap. Spinner-of-Rope had been left too long in that nightfighter pilot cage, Louise thought. Spinner had seen too much, too fast…
Since she’d been retrieved from the cage Spinner had seemed healthy enough, and Mark assured Louise that she’d retained her basic sanity. Even her illusion of communicating with Michael Poole — an illusion she’d dropped as they came through the Ring — seemed to have had some, unfathomable, basis in reality, Mark said.
Fine. But, Louise sensed, Spinner-of-Rope still wasn’t fully recovered from her ordeal. She still wasn’t whole. It would take time — decades, perhaps — for the post-traumatic stress to work its way out of her system. Well, Spinner-of-Rope would have the time she needed, Louise was determined.