God is infinite, so His universe must be too. Thus is the excellence of God magnified and the greatness of His kingdom made manifest; He is glorified not in one, but in countless suns; not in a single earth, a single world, but in a thousand thousand, I say in an infinity of worlds.Giordano Bruno was one of the most insightful cosmologists ever to live. Over four hundred years ago he suggested that our Sun is in fact just another star, and the universe is infinite. He was spot on with the first part, and the second is still a matter of some debate. Unfortunately, as a Dominican friar, his views were somewhat at odds with that of the Vatican. He was convicted of heresy and burned at the stake in 1600.
— Giordano Bruno
On the Infinite Universe and Worlds, 1584.
His ideas were so close to those of modern day physics it borders on suspicious. Following the ideas of Copernicus he proposed a universe that is homogenous, roughly the same and obeying the same laws from place to place, a precursor to Einstein's relativity. He removed the Earth and even the Sun from their notional places at the centre of the universe and proposed a cosmos filled with stars, all with their own planets in orbit.
Smart bloke - although sadly not fireproof.
