Revolutionary Italian scientist Galileo Galilei (Topol) makes a series of observations of the Venetian night sky that he believes confirm the veracity of the Copernican model of the universe, a model that places the sun, rather than the Earth, at its center. As Galileo rises to prominence, he moves his base of operations to Florence, where his ideas, considered blasphemous, come under the increased scrutiny of officials in the higher echelons of the Roman Catholic Church.