Odeen therefore said, “Yes, Tritt. We’ll be out of your way.”

And Dua extended a briefly loving part of herself and said, “It’s good to see you, right-dear.” (Odeen wondered if her gesture was part relief over the fact that there would be no pressure to melt. Tritt did tend to overdo that a bit; even more than Parentals generally.)

In her chamber, Dua stared at her private feeding-place. Ordinarily, she ignored it.

It had been Odeen’s idea, He knew that such things did exist and, as he explained to Tritt, if Dua did not like to swarm with the other Emotionals, it was perfectly possible to lead Solar energy down into the cavern so that Dua might feed there.

Tritt had been horrified. It wasn’t done. The others would laugh. The triad would be disgraced. Why didn’t Dua behave as she should?

“Yes, Tritt,” Odeen had said, “but she doesn’t behave as she should, so why not accommodate her? Is it so terrible? She will eat privately, gain substance, make us happier, become happier herself, and maybe learn to swarm in the end.”

Tritt allowed it, and even Dua allowed it—after some argument—but insisted that it be a simple design. So there was nothing but the two rods that served as electrodes, powered by Solar energy, and with room for Dua in between.

Dua rarely used it, but this time she stared at it and said, “Tritt has decorated it ... Unless you did, Odeen.”

“I? Of course not.”

A pattern of colored-clay designs was at the base of each electrode. “I suppose it’s his way of saying he wishes I would use it,” Dua said, “and I am hungry. Besides, if I’m eating, Tritt wouldn’t dream of interrupting us, would he?”

“No,” said Odeen, gravely. “Tritt would stop the world if he thought its motion might disturb you while you were eating.”

Dua said, “Well—I am hungry.”

Odeen caught a trace of guilt in her. Guilt over Tritt? Over being hungry? Why should Dua feel guilty about being hungry? Or had she done something that had consumed energy and was she feeling—

He wrenched his mind away from that impatiently. There were times when a Rational could be too Rational, and chase down the tracks of every thought to the detriment of what was important. Right now, it was important to talk to Dua.

She seated herself between the electrodes and when she compressed herself to do so, her small size was only too painfully evident. Odeen was hungry himself; he could tell because the electrodes seemed brighter than they ordinarily did; and he could taste the food even at that distance and the savor was delicious. When one was hungry, one always tasted food more keenly than otherwise and at a greater distance. ... But he would eat later.

Dua said, “Don’t just sit silently, left-dear. Tell me. I want to know.” She had adopted (unconsciously?) the ovoid character of a Rational, as though to make it clearer that she wanted to be accepted as one.

Odeen said, “I can’t explain it all. All the science I mean, because you haven’t had the background, I will try to make it simple and you just listen. Later, you tell me what you didn’t understand and I’ll try to explain further. You understand, first, that everything is made up of tiny particles called atoms and that these are made up of still tinier subatomic particles.”

“Yes, yes,” said Dua. “That’s why we can melt.”

“Exactly. Because actually we are mostly empty space. All the particles are far apart and your particles and mine and Tritt’s can all melt together because each set fits into the empty spaces around the other set. The reason matter doesn’t fly apart altogether is that the tiny particles do manage to cling together across the space that separates them. There are attractive forces holding them together, the strongest being one we call the nuclear-force. It holds the chief subatomic particles very tightly together in bunches that are spread widely apart and that are held together by weaker forces. Do you understand that?”

“Only a little bit,” said Dua.

“Well never mind, we can go back later.... Matter can exist in different states. It can be especially spread out, as in Emotionals; as in you, Dua, It can be a little less spread out, as in Rationals and in Parentals. Or still less so, as in rock. It can be very compressed or thick, as in the Hard Ones. That’s why they’re hard. They are filled with particles.”

“You mean there’s no empty space in them.”

“No, that’s not quite what I mean,” said Odeen, puzzled as to how to make matter clearer. “They still have a great deal of empty space, but not as much as we do. Particles need a certain amount of empty space and if all they have is that much, then other particles can’t squeeze in. If particles are forced in, there is pain. That’s why the Hard Ones don’t like to be touched by us. We Soft Ones have more space between the particles than are actually needed, so other particles can fit in.”

Dua didn’t look at all certain about that. Odeen hastened onward. “In the other Universe, the rules are different. The nuclear-force isn’t as strong as in ours. That means the particles need more room.”

“Why?”

Odeen shook his head, “Because—because—the particles spread out their wave-forms more. I can’t explain better than that. With a weaker nuclear-force, the particles need more room and two pieces of matter can’t melt together as easily as they can in our Universe.”

“Can we see the other Universe?”

“Oh, no. That isn’t possible. We can deduce its nature from its basic laws. The Hard Ones can do a great many things, though. We can send material across, and get material from them. We can study their material, you see. And we can set up the Positron Pump. You know about that, don’t you?”

“Well, you’ve told me we get energy out of it. I didn’t know there was a different Universe involved.... What is the other Universe like? Do they have stars and worlds the way we do?”

“That’s an excellent question, Dua.” Odeen was enjoying his role as teacher more intensely than usual now that he had official encouragement to speak. (Earlier he always had the feeling that there was a kind of sneaking perversion in trying to explain things to an Emotional.)

He said, “We can’t see the other Universe, but we can calculate what it must be like from its laws. You see, what makes the stars, shine is the gradual combination of simple particle-combinations into more complicated ones. We call it nuclear fusion.”

“Do they have that in the other Universe?”

“Yes, but because the nuclear-force is weaker, fusion is much slower. This means that the stars must be much, much bigger in the other Universe otherwise not enough fusion would take place to make them shine. Stars of the other Universe that were no bigger than our Sun would be cold and dead. On the other hand, if stars in our Universe were bigger than they are, the amount of fusion would be so great it would blow them up. That means that in our Universe there must be thousands of times as many small stars as there are larger stars in theirs—”

“We only have seven—” began Dua. Then she said, “I forgot.”

Odeen smiled indulgently. It was so easy to forget the uncounted stars that could not be seen except by special instruments. “That’s all right. You don’t mind my boring you with all this.”

“You’re not boring me,” said Dua. “I love it. It even makes food taste so good.” And she wavered between the electrodes with a kind of luxurious tremor.

Odeen, who had never before heard Dua say anything complimentary about food, was greatly heartened. He said, “Of course, our Universe doesn’t last as long as theirs. Fusion goes so fast that all the particles are combined after a million lifetimes.”

“But there are so many other stars.”

“Ah, but you see they’re all going at once. The whole Universe is dying down. In the other Universe, with so many fewer and larger stars, the fusion goes so slowly that the stars last thousands and millions of times as long as ours. It’s hard to compare because it may be that time goes at different rates in the two Universes.” He added, with some reluctance, “I don’t understand that part myself. That’s part of the Estwald Theory and I haven’t got to that very much so far.”