She had simply assumed that Volemak would keep the Index in his own tent, but of course that would not do—Zdorab and Issib would be using the Index all the time, and could hardly be expected to arrange their schedule around such inconveniences as an old woman whose husband let her sleep too late in the morning.
Rasa stood outside the door of the small tent and clapped twice.
"Come in."
From the voice she knew at once that it was Issya. She felt a stab of guilt, for last night she had hardly spoken to the boy—the man—that was her firstborn child. Only when she and Volya had spoken to the four unmarried ones all at once, really. And even now, knowing that he was inside the tent, she wanted to go away and come back another time.
Why was she avoiding him? Not because of his physical defects—she was used to that by now, having helped him through his infancy and early childhood, having fitted him for chairs and floats so he could move easily and have a nearly normal life—or at least a life of freedom. She knew his body almost more intimately than he knew it himself, since until he was well into puberty she had washed him head to toe, and massaged and moved his limbs to keep them flexible before he slowly, painfully learned to move them himself. During all those sessions together they had talked and talked—more than any of her other children, Issib was her friend. Yet she didn't want to face him.
So of course she parted the door and walked into the tent and faced him.
He was sitting in his chair which had linked itself to the solar panel atop the tent so he wasn't wasting battery power. The chair had picked up the Index and now held it in front of Issib, where it rested against his left hand. Rasa had never seen the Index but knew at once that this had to be it, if only because it was an object she had never seen.
"Does it speak to you?" she asked.
"Good afternoon, Mother," said Issib. "Was your morning restful?"
"Or does it have some kind of display, like a regular computer?" She refused to let him goad her by reminding her of how late she had arisen.
"Some of us didn't sleep at all," said Issib. "Some of us lay awake wondering how it happened that our wives-to-be were brought in and dumped on us with only the most cursory of introductions."
"Oh, Issya," said Rasa, "you know that this situation is the natural consequence of the way things are, and nobody planned it. You're feeling resentful? Well, so am I. So here's an idea—I won't take it out on you, and you don't take it out on me."
"Who else can I take it out on?" said Issib, smiling wanly.
"The Oversoul. Tell your chair to throw the Index across the room."
Issib shook his head. "The Oversoul would simply override my command. And besides, the Index isn't the Oversoul, it's simply our most powerful tool for accessing the Oversoul's memory."
"How much does it remember?"
Issib looked at her for a moment. "You know, I never thought you'd refer to the Oversoul as it."
Rasa was startled to realize she had done so, but knew at once why she had done so. "I wasn't thinking of her— the Over-soul. I was thinking of it— the Index."
"It remembers everything," said Issib.
"How much of everything? The movements of every individual atom in the universe?"
Issib grinned at her. "Sometimes it seems like that. No, I meant everything about human history on Harmony."
"Forty million years," said Rasa. "Maybe two million generations of human beings. A world population of roughly a billion most of the time. Two quadrillion lives, with thousands of meaningful events in every life."
"That's right," said Issib. "And then add to those biographies the histories of every human community, starting with families and including those as large as nations and language groups and as small as childhood friends and casual sexual liaisons. And then include all natural events that impinged on human history. And then include every word that humans ever wrote and the map of every city we ever built and the plans for every building we ever constructed…"
"There wouldn't be room to contain all the information," said Rasa. "Not if the whole planet were devoted to nothing but storing it. We should be tripping over the Oversoul's data storage with every step."
"Not really," said Issib. "The Oversoul's memory isn't stored in the cheap and bulky memory we use for ordinary computers. Our computers are all binary, for one thing—every memory location can carry only two possible meanings."
"On or off," said Rasa. "Yes or no."
"It's read electrically," said Issib. "And we can only fit a few trillion bits of information into each computer before they start getting too bulky to carry around. And the space we waste inside our computers—just to represent simple numbers. For instance, in two bits we can only hold four numbers."
"A-1, B-1, A-2, and B-2," said Rasa. "I did teach the basic computer theory course in my little school, you know."
"But now imagine," said Issib, "that instead of only being able to represent two states at each location, on or off, you could represent five states. Then in two bits—"
"Twenty-five possible values," said Rasa. "A-l, B-l, V-1, G-1, D-1, and so on to D-5."
"Now imagine that each memory location can have thousands of possible states."
"That certainly does make the memory more efficient at containing meaning."
"Not really," said Issib. "Not yet anyway. The increase is only geometric, not exponential. And it would have a vicious limitation on it, in that each single location could only convey one state at a time. Even if there were a billion possible messages that a single location could deliver, each location could only deliver one of those at a time."
"But if they were paired, that problem disappears, since between them any two locations could deliver millions of possible meanings," said Rasa.
"But still only one meaning at any one time."
"Well, you can't very well use the same memory location to store contradictory information. Both G-9 and D-9."
"It depends on how the information is stored. For the Over-soul, each memory location is the interior edge of a circle –a very tiny, tiny circle—and that inside edge is fractally complex. That is, thousands of states can be represented by protrusions, like the points on a mechanical key, or the teeth on a comb—in each location it's either got a protrusion or it doesn't."
"But then the memory location is the tooth, and not the circle," said Rasa, "and we're back to binary."
"But it can stick out farther or not as far," said Issib. "The Oversoul's memory is capable of distinguishing hundreds of different degrees of protrusion at each location around the inside of the circle."
"Still a geometric increase, then," said Rasa.
"But now," said Issib, "you must include the fact that the Oversoul can also detect teeth on each protrusion—hundreds of different values from each of hundreds of teeth. And on each tooth, hundreds of barbs, each reporting hundreds of possible values. And on each barb, hundreds of thorns. And on each thorn, hundreds of hairs. And on each hair—"