Ping Poo, the Astronomer: A strange discovery (The Growth of Knowledge Book 2)

This is a "philosophy for children" story, dealing with the notion of discovery. Ping Poo is an astronomer of Chinese antiquity, who thinks that stars are holding on to the sky like flies on the ceiling. For his colleague Li Fu, they hang from the sky with strings. They both make observations confirming their theory, which only leads to further disagreements. In order to have a closer examination, they climb a mountain together; as they approach the clouds, Ping Poo makes a strange discovery...