The Ganymean engineers announced that the ship beneath Pithead would provide the parts needed to repair the drive system of the Shapieron and that the work would take three to four weeks. A shuttle service between Pithead and Main came into being as technicians and scientists of both races cooperated in the venture. The Ganymeans, of course, directed and carried out the technical side of the operation while the Earthmen took care of the transportation, logistics, and domestic arrangements. Parties of UNSA experts were invited aboard the Shapieron to observe the work in progress and to stand in spellbound fascination as some of the mysteries and intricacies of Ganymean science were explained. One eminent authority on nuclear engineering from Jupiter Five declared later that the experience made him feel like "an unapprenticed plumber's mate being shown around a fusion plant."

While all this was going on, a team of UNSA specialists at Main worked out a schedule to give ZORAC a crash course on terrestrial computer science and technology. The result of this exercise was the construction of a code-conversion and interface system, most of the details of which were worked out by ZORAC itself, to couple the Ganymean computer directly into the communications network at Main and thus into the computer complex of J5. This gave ZORAC, and through it the Ganymeans as well, direct access to J5's data banks and opened up a mine of information on many aspects of the ways of life, history, geography and sciences of Earth--for which the aliens had insatiable appetites.

One day, in the communications room of the Mission Control Center at UNSA Operational Command Headquarters, Galveston, there was consternation when a strange voice began speaking suddenly and unexpectedly over the loudspeaker system. It was another of ZORAC's jokes. The machine had composed its own message of greeting to Earth and injected it into the outgoing signal stream of the laser link from Jupiter.

Earth was, of course, clamoring to know more about the Ganymeans. In a press conference staged specifically for broadcast over the world news grid, a panel of Ganymeans answered questions put to them by scientists and reporters who had traveled with the J5 mission. A large local audience was expected for the event and, since none of the facilities available at Main seemed to be large enough, the Ganymeans readily agreed to the idea of holding the event inside the Shapieron. Hunt was a member of the group that flew down from Pithead to take part.

The first questions concerned the concepts and principles behind the design of the Shapieron , especially its propulsive system. In reply, the Ganymeans stated that the speculations of the UNSA scientists had been partly right, but did not tell the whole story. The arrangement of massive toroids containing tiny black holes that spun in closed circular paths did indeed generate very high rates of change of gravity potential which resulted in a zone of intense space-time distortion, but this did not propel the ship directly; it created a focal point in the center of the toroids at which a trickle of ordinary matter was induced to annihilate out of existence. The mass-equivalent appeared in the form of gravitational energy, though not in any way as simple as the classical notion of a force directed toward a central point; the Ganymeans described the resultant effect as resembling "a stress in the structure of space-time surrounding the ship. . . ." It was this stress wave that propagated through space, carrying the ship with it as it went.

The idea of being able to cause matter to annihilate at will was astonishing, and that the annihilation should result in artificial gravity phenomena was a revelation. But to learn that all this merely represented a means of bringing under control something that went on naturally anyway all over the universe. . . was astounding. For this, apparently, was exactly the way in which gravity originated in Nature; all forms of matter were all the time decaying away to nothing, albeit at an immeasurably slow rate, and it was the tiny proportion of basic particles that were annihilating at any given moment that gave rise to the gravitational effect of mass. Every annihilation event produced a microscopic, transient gravity pulse, and it was the additive effect of millions of these pulses occurring every second which, when perceived at the macroscopic level, produced the illusion of a steady field. Thus, gravity ceased to be something static and passive that existed wherever a quantity of mass happened to be; now, no longer an oddity standing apart, it fell into line with all the other field phenomena of physics and became a quantity that depended on the rate of change of something--in this case, the rate of change of mass. This principle, together with the discovery of a means of artificially generating and controlling the process, formed the basis of Ganymean gravitic engineering technology.

This account caused consternation among the scientists from Earth who were present. Hunt voiced their reactions by asking how some of the fundamental laws of physics--conservation of mass-energy and momentum, for example--could be reconciled with the notion of particles being able to vanish spontaneously whenever they chose. The cherished fundamental laws, it turned out, were neither fundamental nor laws at all. Like the Newtonian mechanics of an earlier age, they were just approximations that would be repealed with the development of more precise theoretical models and improved measurement techniques, similar to the way in which careful experiments with light waves had demonstrated the untenability of classical physics and resulted in the formulation of special relativity. The Ganymeans illustrated the point by mentioning that the rate at which matter decayed was such that one gram of water would require well over ten billion years to disappear completely--utterly undetectable by any experiment that could be devised within the framework of contemporary terrestrial science. While that remained true, the established laws that Hunt had referred to would prove perfectly adequate since the errors that resulted from them would make no practical difference. In the same way, classical Newtonian mechanics continued to suffice for most day-to-day needs although relativity provided the more accurate description of reality. The history of Minervan science had shown the same pattern of development; when terrestrial science had progressed further, no doubt, similar discoveries and lines of reasoning would lead to the same reexamination of basic principles.

This led to the question of the permanency of the universe. Hunt asked how the universe could still exist at all let alone still be evolving if all the matter in it was decaying at the rate that the Ganymeans had indicated, which was not slow on a cosmic time scale; there ought not to have been very much of the universe left.

The universe went on forever, he was told. All the time, throughout the whole volume of space, particles were appearing spontaneously as well as vanishing spontaneously, the latter process taking place predominantly inside matter--naturally, since that was where there were more of them to vanish from in the first place. Thus the evolution of progressively more complex mechanisms of creating order out of chaos--basic particles, interstellar clouds, stars, planets, organic chemicals, then life itself and after that intelligence--formed a continuous cycle, a perpetual stage where the show never stopped but individual actors came and went. Underlying it all was a unidirectional pressure that strove always to bring high levels of organization from lower ones. The universe was the result of a conflict of two opposing, fundamental trends; one, represented by the second law of thermodynamics, was the tendency for disorder to increase, while the other--the evolutionary principle--produced local reversals by creating order. In the Ganymean sense, the term evolution was not something that applied only to the world of living things, but one that embraced equally the whole spectrum of increasing order, from the formation of an atomic nucleus from stellar plasma to the act of designing a supercomputer; within this spectrum, the emergence of life was reduced to just another milestone along the way. They compared the evolutionary principle to a fish swimming upstream against the current of entropy; the fish and the current symbolized the two fundamental forces in the Ganymean universe. Evolution worked the way it did because selection worked; selection worked because probability worked in a particular way. The universe was, in the final analysis, all a question of statistics.