Their theory was called heliocentric, meaning that the sun was the center of solar system, and Earth and the other planets revolved around it.

The first person who put forward the heliocentric hypothesis was Aristarchus of Samos (310-230 BC). He was known as ‘the mathematician’ and his theoretical contributions to geography. He elaborated the heliocentric theory of the universe.

Aristarchus perhaps influenced by the work of Heraclides of Pontus suggested that a simple world system would result if the sun were put at the center of the universe and of the moon, the earth, and the five then-known planets revolved around the sun in orbits of different sizes and speeds.

Mathematician Pythagoras, in the sixth century before our era also proposed the same ideas. After him Philolaus, had suggested the movement of the earth and planets about a central fire but its definitive formulation appears to be Aristarchus work.

However, Copernicus worked out his system in full mathematician detail. Nicolaus Copernicus read the ideas of ancient Greek astronomers and mathematicians.

In 1512, Copernicus published a description of his ‘heliocentric’ model of the solar system. In this model, the sun was the center of the solar system.

Galileo Galilei (1564-1642) an Italian mathematician and scientist later proved the heliocentric theory.

His telescope also showed that the moon had peaks and valleys, crags and carters and that the sun had spots that appeared and disappeared, disapproving the Aristotelian-Christian belief of pristine heavens.

*Heliocentrism theory*