Nicolaus Copernicus (1473 - 1543) was a 16th century Polish astronomer, mathematician, and physician, amongst other occupations, who developed the heliocentric theory, explaining that the Earth revolves around the Sun.
Copernicus is mentioned in the third season Dinosaurs episode "Charlene's Flat World," not in connection with heliocentrism, but the "flat earth" theory. A Muse gives Charlene Sinclair the revelation that the earth is round like an orange, by mistake, and thus Copernicus' striking discovery becomes a plate of fudge-nut brownies.
In historical fact, Copernicus was not the first to argue that the earth was not flat. However, geocentrism (the idea that all planetary bodies revolved around the earth) was closely tied to the flat earth theory; thus, the work of Copernicus helped pave the way for the later challenges of Galileo.