Discoveries posed direct challenges to Aristotle's idea of the perfection of the heavens. Some astronomers refused to look through Galileo's telescope, others tried to deny what he had seen. The Roman Catholic Church, however, was becoming increasingly concerned—and a young Dominican, Tommaso Caccini, was the first to denounce Galileo officially and the Copernican theory his observations seemed to support from the pulpit during a sermon in the Duomo, or Cathedral, of Florence.
In 1543 Copernicus wrote De revolutionibus, a work that placed the sun at the center of the universe and the planets in semi correct orbital order around it; his work was an attempt to revise the earlier writings of Ptolemy. Galileo's most famous invention was an accurate telescope through which he observed the heavens; he recorded his findings in Sidereus nuncius [starry messenger] (1610). Galileo's Dialogue… sopra i due massimi sistemi del mondo [dialogue concerning the two chief world systems] (1632), for which he was denounced by the current pope (because of Galileo's approval of Copernicus), resulted in his living under house arrest for the rest of his life. Tycho Brahe gave an accurate estimate of planetary positions and refuted the Aristotelian theory that placed the planets within crystal spheres. Kepler was the first astronomer to suggest that planetary orbits were elliptical.
The study of Mathematics in particular was disputed by many, because of its strong association with trade and commerce. Merchants and master craftsmen in many areas in Europe were not given an identical level of respect or deference as they commanded in Germany. This meant that sons of the merchant class were taught only in those subjects which would aid them in their efforts to become statesmen and politicians. What little mathematics was taught in the merchant schools therefore became highly theoretical and divorced from possible applications in the real world.