After long and patient work, however, our galactic society succeeded in forming a fairly complete survey of the cosmical population of galaxies. It was discovered that at this time the many galaxies were in many stages of mental, as of physical, development. Many very young systems, in which nebular matter still predominated over stars, contained as yet no planets. In others, though already there was a sprinkling of the vital grains, life had nowhere reached the human level. Some galaxies, though physically mature, were wholly barren of planetary systems, either through sheer accident or by reason of the exceptionally sparse distribution of their stars. In several, out of the millions of galaxies, a single intelligent world had spread its race and its culture throughout the galaxy, organizing the whole as an egg's germ organizes into itself the whole substance of the egg. In these galaxies, very naturally, the galactic culture had been based on the assumption that from the one single germ the whole cosmos was to be peopled. When telepathic intercourse with other galaxies was at last stumbled upon, its effect was at first utterly bewildering. There were not a few galaxies in which two or more such germs had developed independently and finally come into contact. Sometimes the result was symbiosis, sometimes endless strife or even mutual destruction. By far the commonest type of of galactic society was that in which many systems of worlds had developed independently, come into conflict, slaughtered one another, produced vast federations and empires, plunged again and again into social chaos, and struggled between whiles haltingly toward galactic Utopia. A few had already attained that goal, though seared with bitterness. More were still floundering. Many were so undermined by war that there seemed little prospect of recovery. To such a type our own galaxy would have belonged had it not been for the good fortune of the Symbiotics.
To this account of the galactic survey two points should be added. First, there were certain very advanced galactic societies which had been telepathic spectators of all history in our own and all other galaxies. Secondly, in not a few galaxies the stars had recently begun unexpectedly exploding and destroying their girdles of worlds.
2. DISASTER IN OUR GALAXY
While our Galactic Society of Worlds was perfecting its telepathic vision, and at the same time improving its own social and material structure, the unexpected disasters which we had already observed from afar forced it to attend strictly to the task of preserving the lives of its constituent worlds.
The occasion of the first accident was an attempt to detach a star from its natural course and direct it upon an inter-galactic voyage. Telepathic intercourse with the nearest of the foreign galaxies was fairly reliable, but, as I have said, it had been decided that a physical exchange of worlds would be invaluable for mutual understanding and cooperation. Plans were therefore made for projecting several stars with their attendant systems of worlds across the vast ocean of space that separated the two floating islets of civilization. The voyage would of course be thousands of times longer than anything hitherto attempted. At its completion many more of the stars in each galaxy would already have ceased to shine, and the end of all life in the cosmos would already be in sight. Yet it was felt that the enterprise of linking galaxy with galaxy throughout the cosmos in this manner would be well justified by the great increase of mutual insight which it would produce in the galaxies in the last and most difficult phase of cosmical life.
After prodigies of experiment and calculation the first attempt at intergalactic voyaging was undertaken. A certain star, barren of planets, was used as a reservoir of energy, both normal and sub-atomic. By cunning devices far beyond my comprehension this fund of power was directed upon a chosen star with planetary girdles in such a way as to sway it gradually in the direction of the foreign galaxy. The task of securing that its planets should remain in their true orbits during this operation, and during the subsequent acceleration of their sun, was very delicate, but was accomplished without the destruction of more than a dozen worlds. Unfortunately, just as the star was correctly aimed and was beginning to gather speed, it exploded. A sphere of incandescent material, expanding from the sun with incredible speed, swallowed up and destroyed every girdle of planets. The star then subsided.
Throughout the history of the galaxy such sudden effulgence and quiescence of a star had been a very common occurrence. It was known to consist of an explosion of subatomic energy from the star's superficial layers. This was caused sometimes by the impact of some small wandering body, often no bigger than an asteroid; sometimes by factors in the star's own physical evolution. In either case the Galactic Society of Worlds could predict the event with great accuracy and take steps either to divert the intruding body or to remove the threatened world-system out of harm's way. But this particular disaster was entirely unforeseen. No cause could be assigned to it. It infringed the established laws of physics.
While the Society of Worlds was trying to understand what had happened, another star exploded. This was the sun of one of the leading world-systems. Attempts had recently been made to increase this star's output of radiation, and it was thought that the disaster must have been due to these experiments. After a while another and yet other stars exploded, destroying all their worlds. In several cases attempts had recently been made either to alter the star's course or tap its stored energy.
The trouble spread. System after system of worlds was destroyed. All tampering with stars had now been abandoned, yet the epidemic of "novae" continued, even increased. In every case the exploding star was a sun with a planetary system.
The normal "nova" phase, the explosion caused not by collision but by internal forces, was known to occur only in a star's youth or early maturity, and seldom, if ever, more often than once in each star's career. In this late phase of the galaxy far more stars had passed the natural "nova" stage than not. It would be possible, therefore, to move whole systems of worlds from the dangerous younger stars and settle them in close orbits round the older luminaries. With immense expense of energy this operation was several times performed. Heroic plans were made for the transformation of the whole galactic society by migration to the safe stars, and the euthanasia of the excess population of worlds that could not be thus accommodated.
While this plan was being carried out it was defeated by a new series of disasters. Stars that had already exploded developed a power of exploding again and again whenever they were girdled with planets. Moreover, yet another kind of disaster now began to occur. Very aged stars, which had long since passed the period when explosion was possible, began to behave in an astounding manner. A plume of incandescent substance would issue from the photosphere, and this, as the star revolved, would sweep outwards as a trailing whirl. Sometimes this fiery proboscis calcined the surface of every planet in every orbit, killing all its life. Sometimes, if the sweep of the proboscis was not quite in the plane of the planetary orbits, a number of planets escaped. But in many cases in which the destruction was not at first complete the proboscis gradually brought itself more accurately into the planetary plane and destroyed the remaining worlds.