Far-Seer

“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.”

Afsan’s jaw dropped open; his tail swished in agitation. “But the Face of God has no ring around it.”

“True.”