“Obviously, then, there’s a flaw with the theory,” said Keith.
Jag lifted his upper shoulders. “Indeed. We astrophysics types have been limping by for centuries with something called ‘the density-wave model’ for explaining the abundance of spiral galaxies. It proposes a spiral-shaped disturbance that moves through the medium of a galactic disk, with stars getting caught up in it—or even being formed by it—as the wave rotates. But it has never been a satisfactory theory. First, it fails to account for all the different types of spiral forms, and, second, we don’t have a good answer as to what would cause these imagined density waves in the first place. Supernova explosions are sometimes cited, but it’s just as easy to model such explosions canceling each other out as it is to get them to build up long-duration waves.” He paused. “We’ve had other problems with our galaxy-formation models, too. Back in 1995, human astronomers discovered that distant galaxies, observed when they were only twenty percent of the current age of the universe, had rotational rates comparable to what the Milky Way has today—that’s twice as fast as they should have been rotating at that age, according to theory.”
Keith thought for a second. “But if what we’re seeing right now is correct, then spiral galaxies like ours must somehow form from simple disks, right?”
Another lift of the Waldahud’s upper shoulders. “Perhaps. Your Edwin Hubble proposed that galaxies each start as a simple sphere of stars, gradually spin out into a flat disk, then develop arms that open up more and more over time. But although we now have observational proof that that sort of evolution does indeed happen”—he gestured at the disk of stars in the glowing frame—“we still don’t have an explanation for why the evolution takes place, or why the spiral structures persist.”
“But you say three quarters of all large galaxies are spirals?” asked Lianne.
“Wellll,” said Jag, PHANTOM translating a hissing bark as a protracted word, “actually, we don’t know much directly about the ratio of elliptical to nonelliptical galaxies in the universe at large. It’s hard to make out structure in dim objects that are billions of light-years away. Locally, we see that there are many more spirals than there are ellipticals, and that spirals contain a preponderance of young blue stars, whereas our local ellipticals contain mostly old red stars. We’ve assumed, therefore, that any vastly distant galaxy that showed lots of blue light—after correcting for redshift, of course—was a spiral, and any that showed mostly red was an elliptical, but we really don’t know that for sure.”
“It’s incredible,” said Lianne, looking at the image. “So—so if that’s how it looked six billion years ago, then none of the Commonwealth homeworlds yet exists, right? Is there—do you suppose there’s any life in the galaxy now?”
“Well, ‘now’ is still ‘now,’ of course,” said Jag. “But if you’re asking if there was any life in the Milky Way hack when that light started its journey to us, I would say no. Galactic cores are very radioactive—even more so than we used to think. In a large elliptical galaxy, such as we’re seeing here, the whole galaxy is essentially the core. With stars that close together, there would be so much hard radiation everywhere that stable genetic molecules wouldn’t be able to form.” He paused. “I guess that means it’s only middle-aged galaxies that can give rise to life; young, armless ones will be sterile.”
There was silence on the bridge for a time, broken only by the gentle hiss from the air-circulating equipment and the occasional soft beep from a control panel. Each person contemplated the small fuzzy blot of light that one day would give rise to all of them, contemplated the fact that they were farther out in space than anyone had ever been before, contemplated the vastly empty darkness all around them.
Six billion light-years.
Keith remembered reading about Borman, Lovell, and Anders, the Apollo 8 astronauts who had circled the moon over Christmas of 1968, reading passages from Genesis back to the people on Earth. They had been the first human beings to get far enough from the homeworld so that they could cup it in an outstretched hand. Maybe more than any other single event, that view, that perspective, that image, had marked childhood’s end for humanity—the realization that all their world was one tiny ball floating against the night.
And now, thought Keith, maybe—just maybe—this image was the one that marked the beginning of middle age: a still frame that would become the frontispiece of volume two of humanity’s biography. It wasn’t just Earth that was tiny, insignificant, and fragile. Keith lifted his hand and reached out toward the hologram, cupping the island of stars in his fingers. He sat silently for a long moment, then lowered his hand, and allowed his eyes to wander over the overwhelming dark emptiness that spread out in all directions. His gaze happened to pass over Jag—who was doing exactly what Keith had done a moment ago, using one of his hands to cup the Milky Way.
“Excuse me, Keith,” said Lianne, the first words spoken by anyone on the bridge for several minutes. Her voice was soft, subdued, the way one would talk in a cathedral. “The electrical system is repaired. We can launch that probe anytime you like.”
Keith nodded slowly. “Thank you,” be said, his voice wistful. He looked once more at the young Milky Way floating in the darkness, and then said softly, “Rhombus, let’s have a look at what’s going on back home.”
Chapter XX
“Launching probe,” said Rhombus.
In the holo bubble, Keith could see the silver-and-green cylinder moving away from the ship, illuminated by a tracking searchlight on Starplex’s hull. It looked out of place against the fuzzy splotches of distant galaxies. Soon the probe touched the shortcut and disappeared.
“The run should only take about five minutes,” said Rhombus.
Keith nodded, trying to contain himself. He didn’t know which he wanted more: to have the probe report that it had detected Rissa’s transponder—meaning the Rumrunner was at least still intact—or for it to report nothing, meaning the probeship might have made it through the shortcut to safety.
Time passed, and Keith’s nervousness grew. A watched pot never boils, but…
He looked up at the trio of clocks floating in space above the hidden port-side door. “How long has it been?”
“Seven minutes,” said Rhombus.
“Shouldn’t your probe be back by now?”
Lights moved up the Ib’s web.
“Then where the hell—”
“Tachyon pulse!” announced Rhombus. “Here it comes.”
“Don’t wait until it’s docked,” said Keith. “Download the data by radio and display it.”
“Doing so with delight,” said Rhombus. “Here we go.”
The probe’s scan was low resolution, and video, rather than holographic. A part of the all-encompassing bubble was framed off in blue, and playback of the flatscreen images the probe had recorded began to appear.
“What the—?” said Keith. “Rhombus, did you use the correct angle of approach?”
“Yes—to within a fraction of a degree.”