In the 3rd century BC, Aristarchus of Samos developed a heliocentric model in which the sun is at the centre, with Earth and the other planets revolving around it. This model was rejected by other scientists until Nicolaus Copernicus picked it up again 1,800 years later and initiated the Copernican Revolution. One of the reasons for the rejection of a heliocentric model was that stellar parallax, the apparent shift of position of any nearby star against the background of distant objects, could not be observed […]