The investigation-team from the East arrived to learn from Soames all about the landing of the ship.
He told them, giving them the tape from the wave-guide radar and speaking with strict precision of every event up to the moment of his arrival at Gissell Bay with the children and their artifacts. He did not mention telepathy or time-travel because they seemed so impossible.
When the military men wanted information about instantly available super-weapons, he told them that he knew nothing of weapons. They'd have to judge from the gadgets the children had brought. When the public-relations men asked briskly from what other planet or solar system the spaceship had come, and when a search-ship might be expected, looking for the children, he was ironic. He suggested that the children might give that information if asked in the proper language. He didn't know it. But the two physicists were men whose names he knew and respected. They listened to what he said. They'd look at the devices from the ship and then come back and talk to him.
He went back to his brooding. The children had travelled through time. Everything pointed to it, from the meteor-watch radar to the children's reaction at sight of the pock-marked moon and their knowledge that there should have been a Fifth Planet, to which they assigned four moons. It had happened. Positively. But there was one small difficulty. If time-travel were possible, a man travelling about in the past might by some accident kill his grandfather, or his father, in which case he could not be born, and hence could not possibly go back in time. But if he did not go back in time he would be born and could face the possibility of preventing his own existence—if time-travel was possible. But this was impossible, so time-travel was impossible.
On a higher technical level, there is just one law of nature which seems infallibly true, since its latest modification to allow for nuclear energy. It is the law of the conservation of mass and energy. The total of energy and matter taken together in the universe as a whole, cannot change. Matter can be converted to energy and doubtless energy to matter, but the total is fixed for all time and for each instant of time. So, if a ship could move from one time-period to another, it would lessen the total of matter and energy in the time-period it left, and increase the total when—where—where-when it arrived. And this would mean that the law of the conservation of mass and energy was wrong. But it wasn't. It was right.
Soames tried to reconcile what he had to accept with what he knew. He failed. He provisionally conceded that the children's civilization did something which in his frame of reference was impossible. They had other frames of reference than his. He tried to find their frame of reference in something simpler than time-travel. He picked one impossible accomplishment and tried to duplicate it, then to approach it, then to parallel it. He scribbled and diagrammed and scowled and sweated. He had no real hope, of course. But presently he swore abruptly and stared at what he had drawn.
He'd begun a second set of diagrams when the two physicists of the investigation-team came back. There was a short man and a thin one. They looked dazed.
"They are children," said the thin man in a very thin voice, "and they are human children, and their science makes us ridiculous. They are centuries ahead of us. I could not understand any device they had. I could not imagine how any of them worked."
"It is impossible to talk at a distance," said Soames.
"What do you mean?" asked the thin man, still numb from what he'd seen.
"Sound diminishes as the square of the distance," Soames explained. "You can't make a sound—unless you use a cannon—that can be heard ten miles away. It's impossible to talk at a distance."
"I feel crazy too," said the short man, "but there are telephones."
"It's not talking at a distance. You talk to a microphone at a few inches. Someone listens to a receiver held against his ear. You don't talk to the man, but the microphone. He doesn't listen to you, but a receiver. The effect is the same as talking at a distance, so you ignore the fact that it isn't. I've played a game with the things the children brought. I won it, one game."
Both men listened intently.
"I've been pretending," said Soames, "that I'm a member of the kids' race, cast away like they are on Earth. As a castaway I know that things can be done that the local savages—us—consider impossible. But I need special materials to do them with. My civilization has provided them. They don't exist here. But I refuse to sink to barbarism. Yet I can't reconstruct my civilization. What can I do?"
The thin physicist suddenly raised his head. The short man looked up.
"I'll take what materials the savages of Earth can supply," said Soames. "I'll settle for an approximation. And in practice, as a castaway in a savage environment, I'll wind up with a civilization which isn't that of the savages, and isn't of my own race, but in some ways is better than either because it's tailored to fit the materials at hand and the environment I'm in."
The short physicist said slowly:
"I think I see what you're driving at. But it's just an idea...."
"I tried it on that one-way heat conductor," said Soames. "I can't duplicate it. But I've designed something that will mean nearly but not quite what their cooking-pot does. Take a look at this."
He spread out the completed diagram of the first thing he'd worked on. It was quite clear. He'd helped design the meteor-watch radar at Gissell Bay, and his use of electronic symbols was normal. There was only one part of the device that he'd needed to sketch in some detail. The thin physicist traced the diagram.
"You've designed a coil with extremely low self-induction—"
"Not low," corrected Soames. "Negative. This has less than no self-induction. It feeds back to instead of fighting an applied current. Put any current in it, and it feeds back to increase the magnetism until it reaches saturation. Then it starts to lose its magnetism and that feeds back a counter-emf which increases the demagnetizing current until it's saturated with opposite polarity. You get an alternating magnet, which doesn't evolve heat because of its magnetic instability, but absorbs heat trying to maintain its stability. This thing will absorb heat from anywhere—the air, water, sunlight or what have you—and give out electric current."
The two scientists stared, and traced the diagram again, and stared at each other.
"It—should!" said the thin man. "It—it has to! This is magnificent! It's more important than one-way heat conduction! This is ..."
"This is not nearly as convenient as a pot that gets cold on the outside so it can get hot on the inside," observed Soames. "From a castaway's standpoint it's crude. But this is what can happen from two civilizations affecting each other without immediately resorting to murder. You might try it."
The two physicists blinked. Then the short man said uneasily:
"Can we do it?"
The thin man said more feverishly than before:
"Of course! Look at that weather-making thing! We can't duplicate it exactly, but when you think— There's no Hall effect in liquids. Nobody ever tried to find one in ionized gases. But when you think—"
The short man gulped. Then he said:
"You won't change the temperature, and to make an equation—"
They talked to each other, feverishly. They scribbled. They almost babbled in their haste. When the other members of the investigating-team arrived, they had the look of men who walk on clouds.
The military men were not happy. They were empty-handed. They could not even get statistical information from the children.
They had no useful information. Fran's pocket instrument was cryptic, and held no promise as a weapon. They could not hope to duplicate what Soames had called a super-radar. The cooking-pot, if duplicated, might by modification supply power for ships and submarines, or even planes. But there were no weapons. None.