Scientists like Ptolemy and and Aristotle argue that the Earth is at the centre of the universe, and that the sun and stars are fix on spheres that rotate about the Earth.
However, other scientists like Copernicus and Kepler argue that in fact Earth rotates about the sun. Indeed in Copernicus' time, his model wasn't better than Ptolemy's in predicting the phenomena:
From Wikipedia:
However, for his contemporaries, the ideas presented by Copernicus were not markedly easier to use than the geocentric theory and did not produce more accurate predictions of planetary positions. Copernicus was aware of this and could not present any observational "proof", relying instead on arguments about what would be a more complete and elegant system.
What evidence to we have that the Earth rotates the sun?