The existence of rather advanced concepts like the sphericity of Earth is explained in Vedic literature.
Aitareya Brahmana (3.44) declares: “The Sun does never set nor rise. When people think the Sun is setting (it is not so). For after having arrived at the end of the day it makes itself produce two opposite effects, making night to what is below and day to what is on the other side…Having reached the end of the night, it makes itself produce two opposite effects, making day to what is below and night to what is on the other side. In fact, the Sun never sets”
In fact the very beginning of the Hindu texts of the Bhaagavata mentions earth as the ‘BhooGola’- meaning the sphere of earth.