Symbolism, Imagery, Allegory
Gadzooks! What is this amazing, astounding invention? It's nothing short of an anti-gravity generator, which will complete all of science by adding mind-powers to Unified Field Theory! OH. EM. GEE.
You get the point of the symbol now, right? It represents the biggest scientific discovery possible. Janie explains:
It would turn the whole world upside down, worse than the industrial revolution [...] If things went one way we'd have such a war, you wouldn't believe it. If they went the other way, science would go too far, too fast. (3.14.30)
Yet they only invented it because Lone wanted to help Mr. Prodd move his truck. The farmer couldn't afford a horse, so you know, how about make him an anti-gravity generator to lighten the truck enough to get it out of the mud? Lone did it, the novel tells us, "only because an old man who had taught him something he could not name was mad with bereavement and needed to work and could not afford a horse" (1.28.36) Check out that whole paragraph for the book quite bluntly telling you what you're supposed to take away from the invention.
Then Hip spends most of his adult life tracking it down, and, after he loses it, tracking down its inventor. Yep, that's Part 3 of the novel in twenty words or less.
The point is, the anti-gravity generator is such an amazing gizmo that it motivates Hip to persist in his search despite the setbacks and shows how intelligent the gestalt can be. And did you notice it's the only piece of advanced scientific technology shown in this whole science fiction novel? That's because the passions behind the invention and the gestalt itself—belonging—are what's important in the story.