Nicolaus Copernicus Is Born

In astronomy, heliocentrism is the theory that the Sun is at the center of the Universe. The word came from the Greek (ήλιος Helios = sun and κέντρον kentron = center). Historically, heliocentrism was opposed to geocentrism, which placed the Earth at the center. Though discussions on the possibility of heliocentrism date to classical antiquity, it was not until 1,800 years later, however, in the 16th century, that the Polish mathematician and astronomer Nicolaus Copernicus presented a fully predictive mathematical model of a heliocentric system, which was later elaborated and expanded by Johannes Kepler.

http://en.wikipedia.org/wiki/Heliocentrism