"We call it 'globocentrism' in anthropology. People have a tendency to take it for granted that they are better than their neighbors; that their culture is older and superior to that of other worlds; that what is good in other worlds has been borrowed from them, while what is bad is distorted or perverted in the borrowing or invented elsewhere. And the tendency is to equate superiority in quality with superiority in duration. If they cannot reasonably maintain their own planet to be Earth or its equivalent - and the beginnings of the human species - they almost always do the best they can by placing Earth in their own sector, even when they cannot locate it exactly."
Trevize said, "And you're telling me that Compor was just following the common habit when he said Earth existed in the Sirius Sector. - Still, the Sirius Sector does have a long history, so every world in it should be well known and it should be easy to check the matter, even without going there."
Pelorat chuckled. "Even if you were to show that no world in the Sirius Sector could possibly be Earth, that wouldn't help. You underestimate the depths to which mysticism can bury rationality, Golan. There are at least half a dozen sectors in the Galaxy where respectable scholars repeat, with every appearance of solemnity and with no trace of a smile, local tales that Earth - or whatever they choose to call it - is located in hyperspace and cannot be reached, except by accident."
"And do they say anyone has ever reached it by accident?"
"There are always tales and there is always a patriotic refusal to disbelieve, even though the tales are never in the least credible and are never believed by anyone not of the world that produces them."
"Then, Janov, let's not believe them ourselves. Let's enter our own private hyperspace of sleep."
"But, Golan, it's this business of Earth's radioactivity that interests me. To me, that seems to bear the mark of truth - or a kind of truth."
"What do you mean, a kind of truth?"
"Well, a world that is radioactive would be a world in which hard radiation would be present in higher concentration than is usual. The rate of mutation would be higher on such a world and evolution would proceed more quickly - and more diversely. I told you, if you remember, that among the points on which almost all the tales agree is that life on Earth was incredibly diverse: millions of species of all kinds of life. It is this diversity of life - this explosive development - that might have brought intelligence to the Earth, and then the surge outward into the Galaxy. If Earth were for some reason radioactive - that is, more radioactive than other planets - that might account for everything else about Earth that is - or was unique."
Trevize was silent for a moment. Then, "In the first place, we have no reason to believe Compor was telling the truth. He may well have been lying freely in order to induce us to leave this place and go chasing madly off to Sirius. I believe that's exactly what he was doing. And even if he were telling the truth, what he said was that there was so much radioactivity that life became impossible."
Pelorat made the blowing gesture again. "There wasn't too much radioactivity to allow life to develop on Earth and it is easier for life to maintain itself - once established - than to develop in the first place. Granted, then, that life was established and maintained on Earth. Therefore the level of radioactivity could not have been incompatible with life to begin with and it could only have fallen off with time. There is nothing that can raise the level."
"Nuclear explosions?" suggested Trevize.
"What would that have to do with it?"
"I mean, suppose nuclear explosions took place on Earth?"
"On Earth's surface? Impossible. There's no record in the history of the Galaxy of any society being so foolish as to use nuclear explosions as a weapon of war. We would never have survived. During the Trigellian insurrections, when both sides were reduced to starvation and desperation and when Jendippurus Khoratt suggested the initiation of a fusion reaction in..."
"He was hanged by the sailors of his own fleet. I know Galactic history. I was thinking of accident."
"There's no record of accidents of that sort that are capable of significantly raising the intensity of radioactivity of a planet, generally." He sighed. "I suppose that when we get around to it, we'll have to go to the Sirius Sector and do a little prospecting there."
"Someday, perhaps, we will. But for now..."
"Yes, yes, I'll stop talking."
He did and Trevize lay in the dark for nearly an hour considering whether he had attracted too much attention already and whether it might not be wise to go to the Sirius Sector and then return to Gaia when attention - everyone's attention - was elsewhere.
He had arrived at no clear decision by the time he fell asleep. His dreams were troubled.
They did not arrive back in the city till midmorning. The tourist center was quite crowded this time, but they managed to obtain the necessary directions to a reference library, where in turn they received instruction in the use of the local models of data-gathering computers.
They went carefully through the museums and universities, beginning with those that were nearest, and checked out whatever information was available on anthropologists, archaeologists, and ancient historians.
Pelorat said, "Ah!"
"Ah?" said Trevize with some asperity. "Ah, what?"
"This name, Quintesetz. It seems familiar."
"You know him?"
"No, of course not, but I may have read papers of his. Back at the ship, where I have my reference collection..."
"We're not going back, Janov. If the name is familiar, that's a starting point. If he can't help us, he will undoubtedly be able to direct us further." He rose to his feet. "Let's find a way of getting to Sayshell University. And since there will be nobody there at lunchtime, let's eat first."