Complex sentence: Copernicus' "De revolutionibus" had been published twenty years before Galileo's birth, and while heliocentrism was condemned by Protestant leaders Luther, Calvin and Melanchthon, the Catholic church was more open to the idea.
Split into simpler sentences: Copernicus' "De revolutionibus" had been published twenty years before Galileo's birth,. While heliocentrism was condemned by Protestant leaders Luther, Calvin and Melanchthon, the Catholic church was more open to the idea.