Who first invented the myth that Pangu opened the world?

"Pangu opens the sky" was first seen in Xú Zhēng's Thirty-five Calendars during the Three Kingdoms period. According to folklore, Pangu was born in a dark group in ancient times. He couldn't stand the darkness, so he split it into four directions with an axe and gradually became wider and wider. In order not to reunite heaven and earth, he continued to cast spells. Every foot that Pangu's body grows taller, the sky grows taller. After10.8 million years of hard work, Pangu has become an indomitable giant, with the sky rising too high and the earth becoming extremely thick. Pangu created great achievements in the world before his death, and left endless treasures to future generations after his death, becoming a hero worshipped by the Chinese nation.