Zhang Pingzi is Zhang Heng; separated by two hundred years, Guo Pu unilaterally regards Zhang Heng as his teacher. Zhang Heng believed that the heavens are like an egg, with the sky being the shell and the earth being the yolk; hence, the concept of the heavens being a larger circle encompassing a smaller one.
This is a minor divergence within the broader university theory. They all believe the heavens are circular, but define the details of the circle differently.
Zhao Hanzhang thought, they could very well seek common ground while preserving differences.
"…I agree with Ting Han on this point. But regardless of whether it's dual circles or single ones, can't we set aside the controversy first? They're all circles; why not calculate the eclipse times first?"
Guo Pu: "No, this is an academic dispute. How can one muddle through it? If he doesn't acknowledge the dual circles, I will not calculate this with him."
