Geocentric Universe of  the Ancients:

The  earliest ideas of  the Egyptians and Sumerians about the universe may seem strangeto us. The Earth appeared flat 2nd solid tg them. The Sumerians visualised  the universe as a flaEarth covered by the heaven made up of tin! Between them lay the glowing Sun, Moonplanets and stars which were conuolled by the gods. The Earth was  obviously the principal thing in the universe. Indeed, they knew no reason  to think otherwise. They accepted the Sun, Moon, planets and stars for what they looked like. 

The Earth is Round:

The  idea of a flat Earth was discarded by  the Greeks. As early as 600 B.C.;  the philosopher Thales thought the Earth to be round. Pythagoras and his disciples also  

maintained that  the Earth was spherical. They reasoned  that it must be round becauseof the way ships seemed to sink below the horizon of he  sea (Fig.) or because of the circular shadow it cast on the Moon during an eclipse