Barbara looked at him obliquely, doubting his seriousness.
"Aw, now, Eddie-boy, take it a little bit easy," she said. "Please do."
He didn't answer her. He let his unchanging expression and many seconds of silence do the answering for him. His pulses drummed in his ears.
At last he said, "No, darling, I mean it. There's no reason why an android no bigger than the smallest insects can't exist. And the signs of what Mitchell Prell did in this laboratory are plain enough.
"Working at first with the larger microscope and the miniature tools and machinery under it, he duplicated a now common kind of biological apparatus in half-inch size. In its tank he caused to grow the simulacrum of himself that you can see. Aside from the difference in dimensions, that much has been both possible and fairly common practice for years. Its brain having been stamped with all phases of his memory and personality, it became him when it awoke. His own body he left inert and preserved in the large vat. But he was not finished. He had made just one step toward the degree of smallness that he wanted to reach. So he started over from scratch, constructing first another microscope and then relatively minute machinery and tools, fine beyond our sight. Under that tiny electron microscope I'll bet there's another, smaller machine shop, and a smaller tank from which a mote-sized Mitchell Prell emerged. It must all have been quite a job. It's not hard to see where those ten years went."
Barbara was silent for a long time. Finally, she said, "It sounds reasonable—superficially. But still, is it possible? Consider a brain. It can come in many sizes, from an ant's to a human being's. But all are made of molecules of the same dimensions. And it has been pretty well determined that a brain must be always about as big as a human being's to be truly intelligent. Trying to cram such intelligence into a smaller lump of gray matter—composed of the familiar molecules—would be like trying to weave fine cloth out of rope. How can you get around that, Ed?"
"Maybe I can guess," he said. "With smaller units. How about the electron, Babs? Far smaller than the molecule, certainly. And it's been the soul of the best calculators—thought machines—for a couple of centuries. There isn't any doubt that a brain of microscopic size could function by far finer electronic patterning. No, it probably wouldn't work in natural protoplasm. But we already know the flexibility of vitaplasm: easy to redesign, capable of drawing its energy even from a nuclear source. Well, you figure it out. What have we here but other android advantages? I think my uncle once told me that he meant to go where no one could go exactly as a human being."
"All right, Eddie," she conceded. "I guess I'm persuaded. Proud girl, me. I've got a smart boyfriend. And your uncle—he skips blithely from the bigness of the interstellar regions in his thoughts to the smallness of dust! And he seems, actually, to have done the latter—in person! Is that what we're supposed to accept as truth? If so, he must have been with you all the time, or at least for quite a while. On Earth, even. And he must have come out to Mars with us. He was right in your pocket, riding with the paper and pen. To write, he must have gunked himself up good with the ink inside the pen point. Ugh—what a thought! And maybe he's still in your pocket right now. He—or a tremendously shrunken equivalent of him. Does all this stack up right in your eyes, Ed?" A pallor had crept through Barbara's tan.
"Pretty much so," Ed replied heavily.
"So what do we do now, Ed? Try to follow your uncle's path—down?"