The understanding of this concept evolved over time:
* Ancient Greek Philosophers (6th Century BC): Some thinkers like Pythagoras and Aristarchus of Samos proposed that the Earth might be a sphere and that it revolved around the Sun. However, these ideas were not widely accepted and lacked concrete evidence.
* Nicolaus Copernicus (1543): Copernicus published his heliocentric model, which placed the Sun at the center of the solar system. This was a major shift in understanding, but it was still based on observations and mathematical calculations rather than direct proof.
* Galileo Galilei (early 1600s): Galileo's observations with his telescope provided strong support for the heliocentric model. He observed the phases of Venus, which could only be explained if Venus orbited the Sun.
* Isaac Newton (1687): Newton's law of universal gravitation provided a mathematical framework for understanding why planets orbit the Sun. This law, combined with observational evidence, cemented the understanding that the Earth orbits the Sun.
Therefore, it's not a single discovery but a gradual development of understanding over centuries. We can say that the firm understanding of Earth's orbital motion around the Sun came about in the 17th century with the work of Galileo and Newton.
