Geocentric model that both Venus and Mercury went around the Sun rather than the Earth, but this is no longer accepted. Martianus Capella definitely put Mercury and Venus in orbit around the Sun. Aristarchus of Samos was the most radical. He wrote a work, which has not survived, on heliocentrism, saying that the Sun was at the center of the universe, while the Earth and other planets revolved around it. His theory was not popular, and he had one named follower, Seleucus of Seleucia. In 1543, the geocentric system met its first serious challenge with the publication of Copernicus' "De revolutionibus orbium
Summer term Summer term Summer term is the summer academic term at many British schools and universities and elsewhere in the world. In the UK, 'Summer term' runs from the Easter holiday until the end of the academic year in June or July, and thus corresponds to the Easter term at Cambridge University, and Trinity term at Oxford, Dublin and some other places. 'Summer term' is defined in some UK statutory instruments, such as the Education (Assessment Regulations) (Foundation to Key Stage 3) Order (Northern Ireland) 2007, which says: "summer term" means the period commencing immediately after the Easter holiday and ending