Cities in Flight

which is the usual shorthand form of the primary spindizzy equation, called the Locke Derivation. Blackett, Dirac and Locke all assumed that it would hold true for large bodies, such as gas-giant planets and suns. Show on the blackboard by dimensional analysis why this assumption is invalid.”

As far as Chris was concerned, the answer could have been much more simply arrived at; Dr. Braziller could just have told him that this relationship between gravitation and the spin of a body applied only to electrons and other submicroscopic objects, and disappeared, for all practical purposes, in the world of the macrocosm; but that was not her way. Had she only told him that, it would have come into his mind as a fact like any other fact—for instance, like the facts that the memory cells of the City Fathers were constantly pouring into his ears and eyes—but by her lights he would not have understood it. She wanted him to repeat not only the original reasoning of Blackett, Dirac and Locke, but to see for himself, not just because she told him so, where they had gone astray, and hence why a natural law which had first been proposed in the gas-lit, almost prehistoric year of 1891, and was precisely formulated as the Lande Factor in 1940, nevertheless failed to lift so much as a grain of sand off the Earth until the year 2019.

“But Dr. Braziller, why isn’t it enough to see that they made a mistake? We know that now. Why repeat it?”

“Because that’s what all these great men have labored toward: so that you could do it right, yourself. Up until about the thirteenth century, nobody in the world except a few dedicated scholars could do long division; then Fibonacci introduced the Arabic numbers to the West. Now, any idiot can do what it took a great mind to do in those days. Are you going to complain that because Fibonacci found a better way to do long division, you shouldn’t be required to learn why it’s better? Or that because a great inventor like Locke didn’t understand dimensional analysis, you should be allowed to be just as ignorant, after all these years? They spent their lives making things simple for you that were enormously difficult for them, and until you understand the difficulties, you can’t possibly understand the simplifications. Go back to the blackboard and try again.”

Being in a “live” class had its compensations, though; and one of these was Piggy Kingston-Throop. Piggy—his real name was George, but nobody ever called him that, not even Dr. Braziller—was not much of a prize as a friend and companion, but he was the only member of the small class who was exactly Chris’s age; all the others were much younger. From this Chris deduced that Piggy was not a student, which turned out to be true.

Piggy seemed glad enough to encounter someone who was as retarded as he was, whatever the reasons, and who knew less than he did about a great many subjects which were commonplaces to him. And in many ways he was quite a pleasant sort of fellow; blond, plump and affable, with a ready wit and a tendency to be unimpressed by almost everything that other people considered important. In this last, he made a particularly good foil for Chris, who in his ignorance and in the strangeness of his situation often could not help but be earnest to the point of grimness over what later turned out to be trivia.

Not that Chris allowed these differences over value judgments always to be resolved in Piggy’s favor; they quarreled over them almost from the beginning. The first of these tangles, which soon proved to be a model for the others, involved the subject of the antiagathic drugs.

“You’re going to be a citizen, aren’t you, Piggy?”

“Oh, sure. I’m all set.”

“I wish I were. My trouble is, I don’t even know what I want to do—let alone what I’m good at.”

Piggy turned and stared at him. They had paused on the way from school on the Tudor Tower Place bridge leading over 42nd Street. Long ago, the view from here across First Avenue to the East River had been blocked by the UN Building, but that had been demolished during the Terror, and there was nothing to mark where it had stood but a plaza; and on the far side of that, starry space itself.

“What do you mean, do?” Piggy said. “Oh, maybe you’ll have a little trouble, what with not having been born here. But there’s ways around that. Don’t believe everything they tell you.”

Like many of the things Piggy said, fully 80 per cent of this speech meant nothing to Chris. In self-defense, he could do nothing but answer the question. “You know all this better than I do. But the laws do say pretty clearly that a man has to be good for something before he’s allowed to become a citizen and be started on the drug treatments. Let’s see; there are supposed to be three ways to go about it; and I ought to have them straight, because I just had them put into my head a few days ago.”