Geocentric model fire being lighter than air. Beyond the layer of fire, were the solid spheres of aether in which the celestial bodies were embedded. They, themselves, were also entirely composed of aether. Adherence to the geocentric model stemmed largely from several important observations. First of all, if the Earth did move, then one ought to be able to observe the shifting of the fixed stars due to stellar parallax. In short, if the Earth was moving, the shapes of the constellations should change considerably over the course of a year. If they did not appear to move, the stars are either
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