On one of those not-so-fine days of which their city had rather more than less, Lydia's father said to his daughter, "Now that you're such a big girl, I have to tell you some of the facts of life."

Lydia was embarrassed for her father, since she thought she had already known the facts of life for many years.

"You don't have to," she muttered.

But her father continued, "You know that in my youth I was a student of Mr. Cyrus Teed's. But you haven't heard what Mr. Cyrus Teed told me. A secret, revolutionary fact. He had discovered something that modern science still doesn't understand."

"What is it?" Lydia asked absentmindedly.

"That the earth is hollow," Father said.

This had no effect on Lydia. But then Father lowered his voice as if he didn't want anyone else to hear him, even though the two of them were at home alone, as usual.

"The earth is a hollow ball, and everything that exists is inside the ball," he said and gazed expectantly at Lydia.

"Inside? I don't think so," Lydia said, now truly surprised. "That can't be! It isn't written anywhere."

"Not yet!" Father said. "Not yet! But Cyrus Teed believed that before long it would get into all the textbooks. The whole scientific institution will be overturned!"

"And I suppose we're inside the ball too?" Lydia asked doubtfully.

"Absolutely," Father said. "There we are, along with all the planets and their inhabitants, suns and fixed stars, dust and invisible matter. The whole universe!"

"How can that be? What's outside the ball, then?" Lydia asked.

"What, out there?" Father said. "There's nothing out there. Why should there be? Other scientists have understood everything completely backwards. They imagine that we are standing on the convex outer surface of the ball. Hah! But in fact we're standing on its concave inner surface. Cyrus Teed was the first to realize that. A brilliant man!"

"But does that mean that, for example, China-"

"That's right," Father said. "China isn't under our feet, it's over our heads. Up there!"

And Father pointed toward the high, drifting clouds.

"Oh!" said Lydia, amazed. "In school we were taught something else altogether."

"If we had a powerful enough telescope," Father said, "do you know what we would see, Lydia?"

"Maybe the Great Wall of China," Lydia guessed.

"That's right!" her father said and clapped her on the back.

"What about gravity?" asked Lydia, who was a clever girl.

"You said it," said her father enthusiastically. "There's another fundamental mistake that has been made. We don't stay on the earth's surface because of gravity but because of centrifugal force. When we change the geometry of space, we also change the laws of nature."

"Well, then, what's in the middle of the ball?" Lydia asked.

"Infinity is there," her father answered.

"There?" Lydia asked. "How can it possibly fit in there?"

"Infinity can fit anywhere," Father said. "As we travel toward the center, everything shrinks and slows down, to infinities. Infinity is the essence of everything. Nothing is as small as infinity."

"Has Mr. Teed's theory been proved?" Lydia asked.

"It hasn't been disproved," her father said. "And it never will be, either."