Sobel will discuss her recently published book, which bears the same title as her lecture. By 1514, the Renaissance astronomer Nicolaus Copernicus had a written outline of his then-considered “crazy” theory that the Sun–not the Earth–was the center of the universe. For the next three decades, Copernicus expanded his theory through hundreds of observations and compiled a secret manuscript that explained his theories, but he refused to publish it for fear of ridicule.