Copernicus moves the Earth

De revolutionibus appears in 1543, arguing that the Earth is a planet orbiting the Sun and rotating daily. Copernicus had circulated the idea for decades and delayed publication; he reportedly received the printed book on his deathbed. The model was not initially more accurate than Ptolemy's, and it kept circular orbits and epicycles. What it changed was the question — the Earth's position stopped being an assumption and became a matter of evidence.