Mark said, “Spinner, this universe is just like ours except that it’s around twenty billion years younger.
“This is a baby cosmos. It emerged from its own Big Bang less than a billion years ago. And it’s smaller — space-rime hasn’t had the time to unravel as far as in our old Universe, so this cosmos is something of the order of a hundredth the size. And the stars — ”
“Yes?”
“Spinner, these are the first stars ever to shine here. Not one of the stars we see out there is more than a million years old.”
Out of the primordial nucleosynthesis of the singularity, here, had emerged clouds of hydrogen and helium, with little contamination by heavier elements. The new sky had been dark, illuminated only by the dying echo of the radiation which had emerged from the singularity. Then the gas clouds gathered into proto galactic clumps, each with the mass of a billion Sols. Thermal instabilities had caused the proto galaxies to collapse further, into knots with mass a hundred Suns or more.
Soon, the first of these smooth-burning stars had guttered to life: brilliant monsters, some with the mass of a million Suns.
Slowly, the sky had filled with light.
“The way these stars were born is unique,” Mark said, “because they are the first. There were no previous stars. So the proto-galaxies were a lot smoother — the gas clouds weren’t all churned up by the heat and gravity of earlier generations of stars. And the gas was free of heavy elements. Heavy elements act to keep young stars cooler, and to limit the size of the stars that form. That’s why these babies are so immense.
“These are what we call Population III stars, Spinner. Or VMOs — ‘Very Massive Objects’.”
“If they are so massive,” Spinner said slowly, “then I guess they won’t last so long as stars like Sol.”
Louise looked at her appreciatively. “That’s perceptive, Spinner. You’re right. The VMOs burn their hydrogen fuel quickly. Each of these is going to stay on its Main Sequence for no more than a few million years — two or three, at best. The Sun, on the other hand, should have survived for tens of billions of years, without the interference of the photino birds.”
“What then?” Spinner asked. “What do we do when New Sol goes out?”
Morrow smiled. “Then, I guess, we move on: to another star, and another, and another… We have time here to work that out, I think, Spinner-of-Rope.”
Now New Sol was rising again, over the lip of the pod. The four of them turned instinctively to the light, its flat whiteness smoothing the lines of age and fatigue in their faces.
“In fact,” Mark said, “the star we’ve chosen — New Sol — is already well past its middle age. It’s probably got no more than three-quarters of a million years of its life left.”
Spinner frowned. “That seems stupid. Why not choose a young star, and move there while we can? It may be that when New Sol dies we won’t be able to move away.”
“No,” Mark said patiently. “Spinner, we need an older star.”
The star called New Sol was nearing the end of the second phase of its existence. In the first, it had burned hydrogen into helium. Now, helium was fusing in turn, and a rain of more complex elements had formed a new, inner core: principally oxygen, but also neon, silicon, carbon, magnesium and others.
And later, in the third phase of its life, when the oxygen started to burn, the star would die… although how was far from certain.
“Terrific,” Spinner said. “And we die with it.”
“No,” Mark said seriously. “Spinner-of-Rope, we die without it. Don’t you get it? New Sol is full of oxygen…”
Morrow was pointing, excitedly. “Look. Look. There’s the wormhole… I think it’s almost time.”
Louise turned in her seat.
Now a new form emerged over the rotating pod’s horizon: the familiar shape of a wormhole Interface. This Interface was only a hundred yards across — far smaller than the mile-wide monster the Northern had hauled across a different spacetime — but, like its grander cousins of the past, it shared the classic tetrahedral frame, the shining electric blue color of its exotic matter struts, and the autumn-gold glimmering of its faces. A dozen drone scoop-ships prowled around the Interface, patient, waiting.
Louise felt a prickle of tears in her eyes; she brushed them away impatiently. Already, she thought, we are building things here. Already, we are engineering this universe.
Mark said to Spinner, “If there were planets here we could land and try to terraform one. But there are no planets for us to land on. Anywhere. This is a very young universe. There are no more than traces of heavy elements here, anywhere, outside the interior of the protostars. There are no moons, no comets, no asteroids… We have no raw materials to build with, save the hulk of the Northern — save what we brought here ourselves. We can’t even renew our atmosphere.”
Morrow nodded. “So,” he said, “we’re mining the star.”
The second terminus of this wormhole had been dropped into the carcass of New Sol. Lieserl had accompanied the Interface — just as once she had traveled into the heart of Sol itself. Soon, enriched gases from the heart of the new star would pour into space — here, far from the heat of New Sol, accessible.
The scoop-ships had mouths constructed of electromagnetic fields which could gather in the star-dust across volumes of millions of cubic miles. When the wormhole started to operate, the scoops would sift out the few grains of precious heavy elements.
“The first priority is atmospheric gases,” Mark said. “We lost a lot of our recyclable reserve during the string impact. Another blow-out like that and we’d be finished.”
“Are all the gases we need there, inside the star?”
“Well, there’s plenty of oxygen, Spinner,” Louise said. “But that’s not enough. An all-oxygen atmosphere isn’t particularly stable — it’s too inflammable. We need a neutral buffer gas, to contribute to the hundreds of millibars of pressure we need to stay alive.”
“Like nitrogen,” Spinner said.
“Yes. But there isn’t much nitrogen in New Sol. We should be able to use neon, though…”
“We can replace our other stores. Use the oxygen to make water and food.”
“We can do more than that, Spinner-of-Rope,” Mark said. “In the longer term we can extract heavier elements: magnesium, silicon, carbon — maybe even iron. They are only present in traces in New Sol, but they’re there. We can build a fleet of Northerns, if we’re patient enough. Why, we can even make rocks.”
Spinner looked out at New Sol, and the point light glittered in her eyes, making her look very young, Louise thought. Spinner said, “It’s chilling to think that — except maybe for the Xeelee — we’re alone here, in this universe. Stars like this once burned in our Universe — but they were all extinguished, destroyed, long before humans became conscious.
“We may survive for millions of years here. But, finally, we’ll be gone. New Sol, and all these other stars, will destroy themselves. Eventually, a new generation of stars will form in the enriched galaxies — stars like Sol. And, I guess, intelligence will arise here…