“I read a little Keladax, kilodays ago.”
“You know his dictum: nothing is anything unless it is something. That is, a concept without material reality is meaningless.”
Novato bobbed. “So he said. But Spooltar disagreed. She stated, ‘A true belief is stronger than the mightiest hunter, for nothing can bring it down.’ ” She paused, looked at the ground. At last she said, “I still believe in God, Afsan. Nothing can bring that down.”
“I’m sure of what I said about the Face, though,” Afsan said gently. “I’ve been sure for over a hundred days, but your sketches have made me even more sure.” He leafed through the pages, steering the conversation back to matters of observation and deduction. “Look at the way you drew Kevpel and Bripel, which are the closest other planets to us. You’ve got them both striped horizontally. Like the banded clouds that cross the Face of God.”
Novato shook her head. “I never thought of that.” Then she looked up, bringing her mind back to practical matters, as well. “But you say the Face is a sibling to Kevpel and Bripel, right? Similar to them in structure and each with a large entourage of moons. Then why do Kevpel and Bripel each have rings around them and the Face does not?”
“Exactly,” said Afsan. “Why not, indeed?” He scratched the underside of his muzzle. “Have you mapped the circular paths of the moons around Kevpel and Bripel?”
Novato looked blank. “I don’t know what you mean.”
“I mean, have you examined how far to the left and the right each of the moons appears to get from the disk of the planet? Do any of them move less far left or right than the outermost edge of the planet’s ring?”
“No. They all extend farther than the ring—much, much farther in most cases.”
“Then the moons move outside the ring; they travel beyond it.”
“If you say so.”
“They must; they move in circular paths. The farthest apparent distance from the planet indicates the radius of that circular path.”
N’ovato was quick. She nodded. “And the rings are circular, the particles within them must be moving in their own circular paths.”
Afsan thumped his tail over the back of the bench. “Egg-shells! Think about it: I know from my observations that the farther out a moon is from a planet, the slower it moves in its circular path.”
“All right.”
“And the farther out a planet is from the sun, the slower it moves in its circular path. Kevpel revolves around the sun faster than our planet, the Face, does, and the Face revolves around the sun faster than more distant Bripel does.”
“All right.”
“So: the particles on the inside of the ring must travel faster than the particles on the outside. It couldn’t be a solid ring: the stress between the inside parts wanting to move quickly and the outside parts wanting to move slowly would tear it apart.”
Novato closed her eyes, struggling with the concept. “I’m not sure I understand.”
“Do you have more paper?” Afsan asked.
“Yes. There.” She pointed across the room. Afsan got up, retrieved a leaf and a piece of charcoal, and returned to the bench, sitting even closer to Novato than he had been before.
“See,” he said, sketching a solid circle in the middle of the page. “This is a planet.” Novato nodded. He made a dot. “Well, here’s an object moving around it in a tight circle. That object could be a particle in a ring, or it could be a moon, like the one we live on. Well, let’s say it takes one day to rotate around the planet.” She nodded again. “Now, here’s an object farther out, moving around the planet in a looser circle. Again, it could be a more distant moon, or it could be a particle in the ring that’s farther out. Say this more distant one takes two days to move around the central planet.” He drew the paths of the two objects, so that his planet now had two concentric circles around it.
“So there’s a difference in the… the force, that makes the object swing around the planet, right?” said Novato. “The closer the object, the faster it wants to move in its path.”
“Exactly.”
She reached over, took the charcoal stick from his hand. “But a moon isn’t a point; not when seen through a far-seer, that’s for sure. It’s a sphere.”
Afsan’s turn to look somewhat lost. “Yes?”
“Well, don’t you see?” She drew overtop of the two dots Afsan had made to represent his two different particles, making them into fat circles. Then she pointed with an extended claw. “The inner edge of a moon is closer to the planet that it rotates around than the outer edge is. The inner edge wants to move quickly; the outer edge wants to move slowly.”
“But a moon is a solid object.”
“Right,” said Novato.
“So it can only move at one speed.”
“Perhaps it splits the difference,” said Novato. “If the inner edge wants to take one day to revolve around the planet and the outer edge wants to take two, then the whole thing does it in one and a half days.”
“That makes sense,” said Afsan. “Really, for most moons it wouldn’t be any big deal. Take a distant moon, say one like Slowpoke that takes a hundred days or so to revolve around its planet. Well, maybe the inner side wants to take ninety-nine days and the outer side wants to take a hundred and one. That’s only a one percent variation, nothing major.”
“True,” said Novato.
“And, of course, those moons that are farther out rotate on their own axes at different rates than they revolve around the planet. So it’s not like the same side is always going slower. The stress of going too fast or too slow is evened out over the whole thing.”
“What’s this about rotation rates?” said Novato.
“Well, the moon we’re on always keeps the same side toward the Face of God. That’s why the Face of God is never visible from Land. So the part with Land on it is always moving around the Face of God faster than it really wants to. And the pilgrimage point, directly beneath the Face, and on the other side of our world from Land, is always moving slower than it wants to.”
“Ah, okay,” said Novato. “So the stress does not get evened out.”
“No,” said Afsan. “I guess not. Not really. Yes, over the whole sphere, the difference is split. But some parts are always rotating faster than they want to, and others are always rotating slower than they want to.”
“Is this normal? For a moon to always keep the same side toward the planet it revolves around?”
“It’s normal for moons that are close to their planet, yes. In our system, nine of the thirteen moons seem to always keep the same side facing in. Excuse me: ten of the fourteen moons; I keep forgetting to count us.”
Novato looked puzzled. “But the stress must be significant if you are close to your planet. I mean, we don’t take long at all to rotate around the Face of God.”
“We take exactly one day, of course.”
“Of course,” she said. “That’s not long. And the world’s a big place.”
“Indeed,” said Afsan. “Based on how long it took the Dasheter to make its voyage, I’d say the world has a diameter of about ten or eleven thousand kilopaces.”
“Well, doesn’t that mean that there’s a big difference between the speeds that the Land side and the pilgrimage-point side want to move at?”
“Yes, I guess it does.” Silence for a few moments while both thought. Then Afsan continued. “In fact, I bet there’s a point at which a moon would be so close to the planet it revolves around that the stress between inside and outside would be too much. The difference in the desired speeds of movement would be enough to tear the moon apart.”
“Leaving rubble,” said Novato. “Wait a beat.” She turned, staring off into space. “Wait a beat. How about this? The particles that make up a ring are the rubble left behind from a moon that moved too close to the planet it revolved around. What we see now as the ring around Kevpel might once have been the innermost moon of Kevpel. And the ring around Bripel might have once been the innermost moon of Bripel.”