Afra shut up and the show went on. Had he not been observing from so intimate a spot, Ivo would have suspected it of being entirely fanciful. As it was, he knew that Schön had actually manipulated the macroscope to pick up impulses dating back five or ten billion years; the representation, though indirect, bridged and abridged, was an honest one.
The cloud of primitive gas swirled and contracted, the time scale showing the passage of roughly a million years every 25 seconds. In the course of ten million years the gas cloud compressed itself into a diameter of a hundred million miles, then to a scant one million, and then it flared into life and became a star. The compression had raised its temperature until the hydrogen/helium “ignition” point was achieved; now it was drawing enormous energy from the conversion of hydrogen atoms to a quarter the number of helium atoms.
“It’s like trying to cram four glasses of liquor into a fifth,” Afra explained to Beatryx. “A quart won’t fit into a fifth, so—”
“Doesn’t it depend on the size of the fifth glass?” Oh no, Ivo thought. Once more the two women had crossed signals. Harold would have to untangle them, as he always did. Eventually Beatryx would be made to understand that four hydrogen atoms had a combined atomic weight of 4.04, while a single helium atom’s weight was 4.00. The combination of four hydrogens to make one helium thus released the extra .04 as energy: the life of stars.
Only one percent of the new atom released — but so great was the aggregate that it halted the collapse of the huge cloud/star pictured on the screen and stabilized it for a period. Most of the light of the universe derived from this same process; the myriad stars of the Milky Way Galaxy were merely foci for hydrogen/helium conversion.
Several billion years passed in a few intense minutes. At last the fuel ran low, and the sun swelled into a vast red giant a hundred times its prior diameter.
“That can’t be Sol!” Harold objected. “Our sun is only halfway through its life cycle.”
Schön did not dignify this with a reply. Ivo did not comprehend the situation either, but still knew the image was accurate.
The star, having exhausted its available hydrogen, collapsed again. But within it now was a core of almost pure helium, the product of its lifelong consumption of hydrogen. As it contracted to a much tighter ball than before, the internal temperature increased to ten times that of the earlier conversion. Something had to give. It did: the helium began to break down into carbon. A new fuel had been discovered.
The star was in business again, as a fast-living white dwarf.
But soon the helium ran out, and the tiny star faded into a blackened ball of matter no larger than a planet. It had come to a dismal end. It was dense with collapsed matter and peripheral heavy elements captured during its glory from galactic debris, but it was dead, a drifting ash.
After more millions of years this minuscule corpse was swept into the sphere of influence of a nascent star, a body forming from the more plentiful gas nearer the rim of the galaxy. As the new star, heedless of its degrading destiny, took on the characteristic brilliance of the long atomic conversion, this cinder became a satellite, sweeping up some of the gas for itself. It enhanced its mass and developed an atmosphere, but remained inert. Its day was done; it was never to regain its erstwhile grandeur.
“That’s Earth!” Afra said. Then, immediately: “No, it can’t be. Wrong composition, and the core is much too dense.” She was absorbing the symbols for material and density automatically, seeing the planet as it was.
A second ember was acquired by the young system, also representing the death of an ancient star. Then a third and a fourth, each accruing what pitiful lagniappe it could from the scant debris of space. The last two were much larger cores than the first, and acquired more atmosphere for their dotage, but had no hope of rejuvenation. Four planets orbited the star, each far older as entities than it was.
A neighbor had problems. The picture shifted to cover it for a geologic moment. This star was much larger than the original one and had consumed its hydrogen — and helium — lavishly. In a scant few million years it had run its course. But its mass, and therefore its internal heat, was such that the conversions did not stop at carbon. Oxygen, sodium, silicon, calcium — all the way down to iron, 26 on the atomic scale, the elements formed in this stellar furnace. A series of thermal intensifications — cataclysmic storms — broke through the shell of helium even before its breakdown was complete, producing trace amounts of heavy metals up to lead; but the basic, energy-releasing conversions predominated. The demise of a large star was not a quiet matter.
When nothing remained at the core lighter than iron, the gravitic collapse resumed. The heat ascended to a hundred billion degrees. Strength was drawn from this collapse, and energy poured back into the core to form new matter. The heavier elements all the way up to uranium now were manufactured in quantity.
But at this final collapse the star rebounded in an explosion that splattered its mass across the galaxy: a supernova. A splendid spectrum of heavy elements shot past the more conservative viewpoint star and through its satellite system, and some of this was captured while some fell into the star itself. The system was richer than it had been, feeding greedily upon the gobbets of its neighbor’s destruction.
The original planet intercepted a fair share of this largesse, and gained perceptibly thereby, as did the others. But the largest fragments, mostly iron, fell into orbit and coalesced into planets in their own right. Now three small satellites circled within the four large ones.
“Mars, Earth, Venus!” Afra said, caught up in this adventure. “And the first planet we saw is Neptune — our planet!”
Schön still did not bother to comment. Ivo felt Schön’s concentration as he identified and captured the diverse threads of the macronic tapestry and organized them into a coherent and chronological visual history. This was a task that required all of Schön’s powers, the artistic with the computational and linguistic. They were nevertheless exceptional powers for an exceptional undertaking; Ivo had tended to lose sight of just how potent a mind his mentor-personality possessed. If a mouse born into Leo remained a mouse, a lion confined to the harness of a mouse remained a lion. Or, in this case, a Ram.
More time passed, and the slow accretions continued. A billion years after the first, a second nova developed in the immediate neighborhood. More rich debris angled by, and the sun’s family levied another tax on it, acquiring material for two more inner planets and a number of major moons.
“Mercury and — Vulcan?” Afra inquired. “Or is that Pluto, misplaced?” For there were now five inner planets — one more than could be accounted for.
Schön kept on working.
From distant space, travelers came. Most passed, merely deflected by Sol’s gravity, not captured. One, however, lurched into a wobbly elliptical orbit that passed close to that of planet Jupiter.
“Six inner planets?” Afra demanded in a tone of outrage.
It was not to be. Jupiter wrestled the newcomer around in a harsh initiation, twisting it inward toward the sun… and toward the orbit of the next inward planet. Too close. They drifted, interacted — and came together.
And sundered each other before they touched.
“Roche’s Limit squared,” Afra murmured.
One fragment shot out to intercept planet Saturn, and was captured there — too close. Roche’s Limit exerted itself again: the apprentice moon shattered, and the tiny fragments gradually coalesced into a discernible ring.
A major fragment of the original demolition traveled farther. It intercepted Neptune, where it too broke up, forming two tremendous moons and some fragments. One moon escaped the planet but not the system, and became the erratic outer minion Pluto; the other hooked in close to Neptune and remained as Triton.