Geocentric model knew about Tusi's work or that of the Maragha school. Not all Greeks agreed with the geocentric model. The Pythagorean system has already been mentioned; some Pythagoreans believed the Earth to be one of several planets going around a central fire. Hicetas and Ecphantus, two Pythagoreans of the 5th century BC, and Heraclides Ponticus in the 4th century BC, believed that the Earth rotated on its axis but remained at the center of the universe. Such a system still qualifies as geocentric. It was revived in the Middle Ages by Jean Buridan. Heraclides Ponticus was once thought to have proposed
Rock carvings in Central Norway horse pulling the sun across the sky during the day, and the boat bringing it back through the underworld during night-time. The hunter's rock carvings are often found in places with striking and highly visible natural features, such as below steep cliffs, by waterfalls etc. This was part of what led to the original hunting-magic-interpretation: supposedly the carvings were made in places where animals could easily be hunted. In Central Norway, these sites have a markedly different distribution than the Bronze Age carvings. Sites are found one by one, often in isolated places. The Bronze Age-sites, on the other hand,