 In the Christian world prior to Galileo 's conflict with the Church , the majority of educated people subscribed either to the Aristotelian geocentric view that the earth was the center of the universe and that all heavenly bodies revolved around the Earth , or the Tychonic system that blended geocentricsm with heliocentrism . Nevertheless , following the death of Copernicus and before Galileo , heliocentrism was relatively uncontroversial ; Copernicus 's work was used by Pope Gregory XIII to reform the calendar in 1582 . 
