Nicolaus Copernicus was born on Feb. 19, 1473. He was the first scientist to make the case that the earth revolved around the sun.
His calculations were brilliant, but they weren't perfect. Copernicus made the mistake of assuming that all orbits are circular. But that didn't explain why the planets would sometimes appear to stand still or even move backwards.
The epicycles accounted for those irregular movements by postulating that planets sometimes do "backflips" in the course of their orbits. We now understand that orbits are elliptical, which eliminates the need for such convoluted explanations.