"No, it's not. Trantor is just someplace you can study brittle films and dusty documents and turn brittle and dusty yourself."
"For decades, I've dreamed..."
"You've dreamed of finding Earth."
"But it's only..."
Trevize stood up, leaned over, caught the slack of Pelorat's tunic, and said, "Don't repeat that, Professor. Don't repeat it. When you first told me we were going to look for Earth, before ever we got onto this ship, you said we were sure to find it because, and I quote your own words, 'I have an excellent possibility in mind' Now I don't ever want to hear you say 'Trantor' again. I just want you to tell me about this excellent possibility."
"But it must be confirmed. So far, it's only a thought, a hope, a vague possibility."
"Good! Tell me about it!"
"You don't understand. You simply don't understand. It is not a field in which anyone but myself has done research. There is nothing historical, nothing firm, nothing real. People talk about Earth as though it's a fact, and also as though it's a myth. There are a million contradictory tales..."
"Well then, what has your research consisted of?"
"I've been forced to collect every tale, every bit of supposed history, every legend, every misty myth. Even fiction. Anything that includes the name of Earth or the idea of a planet of origin. For over thirty years, I've been collecting everything I could find from every planet of the Galaxy. Now if I could only get something more reliable than all of these from the Galactic Library at... - But you don't want me to say the word."
"That's right. Don't say it. Tell me instead that one of these items has caught your attention, and tell me your reasons for thinking why it, of them all, should be legitimate."
Pelorat shook his head. "There, Golan, if you will excuse my saying so, you talk like a soldier or a politician. That is not the way history works."
Trevize took a deep breath and kept his temper. "Tell me how it works, Janov. We've got two days. Educate me."
"You can't rely on any one myth or even on any one group. I've had to gather them all, analyze them, organize them, set up symbols to represent different aspects of their content - tales of impossible weather, astronomic details of planetary systems at variance with what actually exists, place of origin of culture heroes specifically stated not to be native, quite literally hundreds of other items. No use going through the entire list. Even two days wouldn't be enough. I spent over thirty years, I tell you.
"I then worked up a computer program that searched through all these myths for common components and sought a transformation that would eliminate the true impossibilities. Gradually I worked up a model of what Earth must have been like. After all, if human beings all originated on a single planet, that single planet must represent the one fact that all origin myths, all culture - hero tales, have in common. - Well, do you want me to go into mathematical detail?"
Trevize said, "Not at the moment, thank you, but how do you know you won't be misled by your mathematics? We know for a fact that Terminus was founded only five centuries ago and that the first human beings arrived as a colony from Trantor but had been assembled from dozens - if not hundreds - of other worlds. Yet someone who did not know this could assume that Hari Seldon and Salvor Hardin, neither of whom were born on Terminus, came from Earth and that Trantor was really a name that stood for Earth. Certainly, if the Trantor as described in Seldon's time were searched for - a world with all its land surface coated with metal - it would not be found and it might be considered an impossible myth."
Pelorat looked pleased. "I withdraw my earlier remark about soldiers and politicians, my dear fellow. You have a remarkable intuitive sense. Of course, I had to set up controls. I invented a hundred falsities based on distortions of actual history and imitating myths of the type I had collected. I then attempted to incorporate my inventions into the model. One of my inventions was even based on Terminus's early history. The computer rejected them all. Every one. To be sure, that might have meant I simply lacked the fictional talents to make up something reasonable, but I did my best"
"I'm sure you did, Janov. And what did your model tell you about Earth?"
"A number of things of varying degrees of likelihood. A kind of profile. For instance, about 90 percent of the inhabited planets in the Galaxy have rotation periods of between twenty-two and twenty-six Galactic Standard Hours. Well - " "
Trevize cut in. "I hope you didn't pay any attention to that, Janov. There's no mystery there. For a planet to be habitable, you don't want it to rotate so quickly that air circulation patterns produce impossibly stormy conditions or so slowly that temperature variation patterns are extreme. It's a property that's self-selective. Human beings prefer to live on planets with suitable characteristics, and then when all habitable planets resemble each other in these characteristics, some say, 'What an amazing coincidence,' when it's not amazing at all and not even a coincidence."
"As a matter of fact," said Pelorat calmly, "that's a well-known phenomenon in social science. In physics, too, I believe - but I'm not a physicist and I'm not certain about that. In any case, it is called the 'anthropic principle': The observer influences the events he observes by the mere act of observing them or by being there to observe them. But the question is: Where is the planet that served as a model? Which planet rotates in precisely one Galactic Standard Day of twenty-four Galactic Standard Hours?"
Trevize looked thoughtful and thrust out his lower lip. "You think that might be Earth? Surely Galactic Standard could have been based on the local characteristics of any world, might it not?"