Born on Feb. 19, 1473 -- Astronomer / Cosmologist Nicolaus Copernicus

from Writer's Almanac (American Public Media: Garrison Keillor):

Today (February 19) is the birthday of the scientist who first proposed that the Earth revolved around the Sun, Nicolaus Copernicus, born in the ancient city of Toruń, Poland (1473).
The Christian Church, Protestants and Catholics alike, held the belief that God had created the Universe just for mankind and so the Earth must be the center of it. But that did not fit with what Copernicus knew about physics and the motion of the planets -- he couldn't make the math work or match his observations -- and he realized that, if he created a new model and moved the Sun to the center, the equations all functioned much more smoothly.
Sometime between 1510 and 1514, Copernicus published his "Little Commentary" on his new model, a 40-page outline of his heliocentric -- sun-centered -- universe, which he sent to various astronomers while he continued working on a much longer, more detailed discussion of the idea. That work became On the Revolutions (1543), which Copernicus dedicated to Pope Paul III, hoping the Pope would protect him from vilification for having removed the Earth from its sacred place. On the Revolutions hardly created a revolution when he wrote it; it was groundbreaking and controversial but, contrary to popular lore, the Church didn't immediately condemn him for it.