heliocentrism

The planets orbit the sun, a la Copernicus, Kepler, Galileo and Newton, although, predictably, the idea came first to some ancient greek philosopher.

Actually, Aristarchus was the first prominent scientist to propose a heliocentric view of the solar system almost 1800 years before Copernicus. The Ptolemic system was the dominant hypothesis for hundreds of years but Copernicus was not unique in his suspicion of it.

It is generally believed that the Church opposed Copernicus's heliocentric theory because geocentrism put Earth and man in an exalted position, in "the image of God". However, in medeival thought, the center of the universe was not a position of importance; it was, rather, the lowest. According to Galileo, geocentrism made the Earth "the sump where the universe's filth and ephemera collect". To put the earth among the stars was to raise man to the status of the angels, which was one reason the church objected to it so strongly.