Nicolaus Copernicus
Engraving of Nicolas Copernicus (1473-1543), Polish astronomer. Copernicus believed that the planetary positions could be calculated more easily if the Sun, rather than the Earth, was at the centre of the Universe. Copernicus continued to believe in perfectly circular orbits. He described his system in a book, but hesitated publishing it due to the heretical nature of its thought. Not until 1543, some weeks before his death, was the book published. The Copernican System as it came to be known hearlded the start of the Scientific Revolution.