Small though it sounded, such a rate of disappearance was not trivial on a cosmic time scale. The reason there was much of the universe left at all was that, throughout the entire volume of space, particles were constantly being created spontaneously, too. And in a converse way to that in which particle-annihilations induced gravity, particle-creations induced “negative gravity.” Since a particle could only disappear from where it already existed, extinctions predominated inside masses and induced an attractive curvature into the local vicinity of space-time; but in the vast regions of empty space between galaxies, creations far outnumbered extinctions, and the resultant effect was a cosmic repulsion. It all made a rather tidy and symmetric, satisfying kind of sense.
A fundamental particle, therefore, appeared, lived out its allotted span in the observable dimensions of the known universe, and then vanished. Where it came from and where it returned to were questions that the scientists of Earth had never had to face, and which even the Ganymeans on Minerva at the time of the Shapieron’s departure had only begun delving into. It was their subsequent work in this direction that had given the Thuriens the technologies that made possible their interstellar civilization.
The hyperrealm that particles temporarily emerged from was the same domain that matter-energy entered when it disappeared into a black hole. That an object no longer continued to exist where it had when it entered a black hole, Terran physicists had known theoretically for some time. Therefore, it had to be either somewhere else in the known universe; or in another universe; or, conceivably, in some other time. Logic admitted no other alternatives. Remarkably, it turned out, all three were possible. The Thuriens had realized and applied the first two; they were still looking into and puzzling over the third.
An electrically charged, rapidly spinning black hole flattened into a disk and eventually became a toroid with the mass concentrated at the rim. In this situation, the singularity existed not as an impenetrably screened point, but as the central aperture itself, which could be approached axially without catastrophic tidal effects. Through a symmetric effect, creating such an “entry port” also gave rise to a coupled projection elsewhere in normal space, at which an object entering the aperture would appear instantaneously by traversing what had come to be known as “i-space.” The location of the “exit port” depended on the dimensions, spin, orientation, and certain other parameters of the initial toroid and could be controlled up to distances of several tens of light-years. That was how the Thuriens moved their craft between stars.
The energy to create the toroids was directed through i-space by colossal generating systems located in space, consuming matter from the cores of burnt-out stars. However, to avoid causing orbital perturbations and all the attendant disruptions, the ports were never projected into planetary systems, but well away in the surrounding voids. To travel between planetary surfaces and the i-space ports, the Thurien ships used an advanced form of the more conventional gravitic drive pioneered by their ancestors on Minerva. Even so, a complete interstellar journey was typically measured in days.
Since the Thurien starships also drew power from the same i-space distribution grid that supplied the energy to create the transfer ports, they could be quite modest in size. Others were huge. The roughly globoid Vishnu, twenty miles across, was of intermediate size.
Three days after Hunt and Danchekker talked with Caldwell, they were part of a mixed group that boarded one of the Vishnu’s daughter craft at Andrews AFB, Maryland. Hunt’s deputy, Duncan Watt, had joined the group as hoped, and so had Sandy Holmes from Danchekker’s lab at Goddard.
It was all as simple and informal an affair as Hunt had expected. The Thurien crew offered them soft drinks or coffee and invited them to take a seat. Each of the arrivals was also issued with a communications device in the form of a small, flexible disk, about the size of a dime and looking like a Band-Aid, that self-attached behind the ear. It was a connection to VISAR, operating via relay from the mother ship orbiting twenty thousand miles overhead. By coupling directly into the wearer’s sensory neural areas, the communicator could, upon command, convey to VISAR what was seen, heard, or spoken; in the reverse direction it could inject information from VISAR, which the wearer would experience as hearing and vision. It thus afforded not only instant access to the ship’s system, but also person-to-person communications with other Terrans, as well as to Ganymeans through VISAR acting as interpreter.
“Welcome back,” the computer’s familiar voice said, seemingly speaking in Hunt’s ear. “I’ take it you’re getting restless again.”
“Hello, VISAR. Well, you seem to be offering a more stylish service these days.” The first vessel that the Thuriens had sent to make initial contact had landed at a disused Air Force base in Alaska and, to evade the Jevlenese-managed surveillance operation, had been built to resemble a conventional Terran aircraft.
“We like to keep the customers happy,” VISAR said.
The ferry craft took off shortly afterward. Barely ten minutes later, it entered the immense composition of soaring hull structures and sweeping metallic surfaces curving away for miles on every side that made up the outer vista of the Vishnu. It entered a brightly lit cavern of projecting docking structures that looked like the Manhattan skyline stood on its side, and berthed alongside another of a fleet of daughter vessels of every size, shape, and description.
Some of the Thurien crew conducted the party through the access ramps and antechambers into a high space with wide corridors leading away on either side and overlooked by several levels of railed walkways. More Thuriens were waiting, scattered about. It seemed to be a terminal area for transportation links to other parts of the vessel, but exactly what one was supposed to do to get there was far from immediately obvious.
The starship manufactured its own internal gravity, creating “up,” “down,” and transitions between in whatever direction suited the purpose from place to place. The result was an Escherian confusion of corridors, shafts, intersecting planes and spaces, and surfaces that served as walls here, floors there, and elsewhere curved to transform from one into another. What had previously been below could unexpectedly appear overhead without one’s experiencing any sense of having rotated, and through it all, streams of Ganymeans were being carried along in open conveyor shafts on directed g-field currents-rather like invisible elevators traversing the ship in all directions. Hunt and Danchekker had seen this kind of thing before, but the others around them were stopping and staring in bewilderment.
“Well, Chris, here we go again,” Hunt said, looking around. “But this will be a darn sight quicker than last time.”
“And a bit more comfortable when we get there, too,” Sandy Holmes murmured in a slightly dazed voice as she struggled to take it all in. She had been with them on the UNSA Jupiter Five mission. When they had joined that ship, before its lift out from lunar orbit, the voyage ahead of them had been six months, and the accommodation waiting at the other end of it had been cramped quarters in the subsurface part of a scientific base situated on Ganymede’s ice sheets, with the constant vibration of machinery and an ever-present odor of hot oil.
“Yes,” Danchekker agreed. “And I recollect being adamant at the termination of that escapade that I would never set foot inside one of these contraptions again.” He sighed. “However, the designers responsible for this accomplishment would appear to have been from a different school from their terrestrial counterparts, whose imaginative limits one must suppose to have been set by experiences with submarines and tanks.”