Smeth had not been the only surprise. More than five thousand people had elected to go along on the genesis quest—almost a third of the human race. The project had tapped a deep longing. The Nar had not underestimated the strength of the buried feelings unearthed in their pets. About ten years into the project, they had begun a program to gather all candidates from the farther worlds, and it had taken another twenty years to bring them all in. Those who had waited too long or who had changed their minds at the last minute had been out of luck.
“Well, I’m glad he decided to come along. It wouldn’t be the same without him.”
“Yes. I have to admit he’s improving.”
Mim fell silent. Bram knew she was thinking about Olan Byr. Immortality had come too late for Olan. The project had been a long, hard one, even with the blueprints of Original Man to work from and the full cooperation of the Nar. There had been times when Bram had thought that he himself would grow too old to benefit from it.
Mim had had fifty years to get over her grief for Olan. Forty of them had been spent with Bram. By the time they had drifted together, she had been too old for children. But her fertility had returned during the last few years, and lately she had been thinking about having a baby after she grew another ten or fifteen years younger. But only if tree demographics permitted, she was always quick to add whenever the subject came up. Yggdrasil could easily support another twenty thousand humans—in fact, about five hundred babies had been born already. But everyone was aware that a long trip lay ahead of them.
Bram reached for her hand, and they exchanged smiles. “Go ahead,” she said. “I’ll finish the packing. You’d better see to Yggdrasil’s tranquilizer. If the drinks get sloshed over the rims of all the glasses on All-Level Eve, Marg will have a fit.”
“Life would certainly be simpler,” he said, “if we didn’t have to rotate our environment thirty degrees every year to keep Yggdrasil from getting lopsided.”
She squeezed his hand. “But it wouldn’t be half as much fun,” she said.
It was an hour’s ride to the trunk even by slingshot, but Bram always enjoyed the view. There was no real reason to make the trip—the tree systems staff was fully competent and, in fact, knew more about the operation of the tree than he did—but the approaching tree-turning maneuver made a good excuse for the excursion.
He reeled in an empty travelpod, eased it through the lips of the gasket, and clambered inside. The absurdly simple arrangement made the expense of air locks for the external travel system unnecessary; otherwise, twelve air locks would have had been installed. The main rack of cables, like an abacus one hundred fifty miles long, was anchored at a new terminus every year, thirty degrees farther along the rim of the tree’s crown, leaving a couple of permanent cables behind for standby access to the abandoned branch.
So far, the only major internal fast-transit system was limited to one branch—the one the human population would be living in during the half millennium when they were coasting between galaxies, and Yggdrasil could be allowed to have its normal one-g spin again. But that was one hundred and twenty degrees away at the moment, its halls and compartments standing on their heads, its pools drained, and everything important either moved or lashed down.
Bram took a moment to check out the pod’s systems. Nothing could go wrong, of course; there was an FM rescue beeper in every pod that would quickly summon help in an emergency. But for someone serving as year-captain, it would be embarrassing to be stranded halfway along the guide rope and have someone come to fetch him.
He made sure the air bladder carried enough reserve for the hour’s trip and that the emergency bottle under the seat was full. He squinted through the hyaloid membrane of the docking chamber’s blister and sighted upward along the elastic cable. The several hundred feet of it that he could see before it came invisible against the distant trunk were reassuringly opaque, indicating that the molecular structure was in a mostly crystalline state.
He grinned as he prepared to change that. He got the little bottle of boron trifluoride out of the dashboard and applied a few drops with an eyedropper to the elastomer line, just forward of the bowline knot that hitched it to an interior stanchion.
The pod gave a shudder as the line began to contract. Bram could see the triggered section turning transparent as its molecular structure became amorphous. The transparent portion shot outward, erasing the cable from sight. A few minutes later, when enough miles of cable had been triggered to overcome the one-g force stretching the line, the pod picked up speed, burst through the gasket, and flew up the guideline toward Yggdrasil’s distant trunk.
Bram held on. He was glad the process wasn’t instantaneous. He wouldn’t have fancied a snapped neck. There was a lot of energy stored in a hundred and fifty miles of superelastic line. As it was, the pod would accelerate at a comfortable rate, never passing two g’s at its zenith, then slow to a bounce as the trailing cable began to tighten.
The organic elastomer, with a stretch ratio of over a thousand to one, was a by-product of the exodus research program and, by departure time, had already found wide industrial application on the Father World. The raw materials came from Yggdrasil itself—derived from the adaptive mechanism by which a tree with a three-hundred-mile diameter synchronized the turgor movements of its leaves.
Bram gazed unabashedly through the transparent skin of his rubbery container and admired the outside view.
Straight up, of course, was a silhouette of Yggdrasil’s trunk seen against the swirling blizzard of sparks created by the ramscoop field some hundreds of miles in front of the tree.
The silhouette was a short, thick bar, lacking detail. The shower of light was pretty—even jolly—but Bram knew that its beauty was a lie. It was the emblem of instant death—the visible by-product of the inferno of radiation pouring into the probe’s magnetic funnel. At more than ninety-nine percent of the speed of light, here in the thick of the galaxy where the H-II clouds were dense, some two hundred trillion hydrogen atoms slammed into every square inch of the electromagnetic shield every second. Even allowing for a gamma factor of twenty thousand—the last figure Jao had given him—that worked out to twenty billion high-energy collisions per second within the ship’s relativistic time frame.
If that shield were to fail for even a fraction of a second at this velocity, five thousand humans would die before their nervous systems were able to register the fact. And Yggdrasil would turn to stardust.
Bram shuddered. As frightening as that umbrella of sparks was, at least it hid the nothingness beyond—the blind spot where the crowded wavelengths of light pushed past the visible spectrum and wiped the stars from the universe. The blind spot behind, eerily framing the artificial sun of the fusion stage of the drive, was bad enough.
He let his eyes follow the long, mirror-bright shaft downward to where the fusion flames burned. The waste light had enough red in it for Yggdrasil to carry on photosynthesis, enough ultraviolet for human sunbathers to tan themselves by behind the lenticels of the recreation areas.
The long shaft threaded a dangerous course between Yggdrasil’s twin domes. At its closest point it passed within forty miles of the trunk, and Yggdrasil itself had provided extra protection there—growing a shield of adventitious leaves with their silvery reflective sides facing out. The star tree could handle anything up through x-rays.
The material part of the shaft was its least important aspect. In fact, its tremendous length could not have held up under even moderate lateral stress. It was there to provide support for the winding coils that deflected the roaring streams of ionized hydrogen in their constricted path from the collection area forward to the ignition cage aft.