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'''Heliocentrism''' is the view that the sun is at the center of the universe. It was proposed by some ancient Greeks,<ref>Aristarchus of Samos (ca. 310-230 BC) proposed it, Archimedes discussed it, and the idea was well-known in Europe when [[Copernicus]] proposed a heliocentric model. [http://galileo.rice.edu/sci/theories/copernican_system.html]</ref> and became the dominant view in the 1700s and 1800s. It was abandoned in the 20th century.

'''Heliocentrism''' is the view that the sun is at the center of the solar system. It was proposed by some ancient Greeks,<ref>Aristarchus of Samos (ca. 310-230 BC) proposed it, Archimedes discussed it, and the idea was well-known in Europe when [[Copernicus]] proposed a heliocentric model. [http://galileo.rice.edu/sci/theories/copernican_system.html]</ref> and became the dominant view in the 1700s and 1800s. It was abandoned in the 20th century.

Since the advent of relativity theory in the early 1900s, the laws of physics have been written in [[covariance|covariant]] equations, meaning that they are equally valid in any frame. Heliocentric and [[Geocentric theory|geocentric]] theories are both used today, depending on which allows more convenient calculations.

Since the advent of relativity theory in the early 1900s, the laws of physics have been written in [[covariance|covariant]] equations, meaning that they are equally valid in any frame. Heliocentric and [[Geocentric theory|geocentric]] theories are both used today, depending on which allows more convenient calculations.