This is a famous
quote by
Galileo that he uttered under his breath (according to
legend) after the
Catholic Church (
the Inquisition) forced him to renounce the
Copernican theory that the
Earth moves around the
Sun. The original
Italian phrase was "Eppur si muove".
The conflict arose from his publishing a book challenging the physics of
Aristotle, which had long since crystallized as accepted
dogma of the church. By challenging accepted dogma, he was committing
heresy in the eyes of the church, and was
ultimately placed under
house arrest for the
remainder of his life.