The story of Copernicus's muse, the mathematician who helped launch modern science.

In the spring of 1539, a twenty-five-year-old mathematics prodigy from Wittenberg named Georg Joachim Rheticus set off on an arduous three-week journey to northern Poland in order to meet the elderly but not-yet-famous amateur astronomer Nicolaus Copernicus. Though he had published nothing on the topic, rumors had abounded for years about Copernicus's revolutionary (many would call it heretical) theory that the Sun, not the Earth, was at the center of the universe, and about a manuscript he had almost completed on the subject.

Intending to stay a month, Rheticus spent three years at Copernicus's side, during which time he persuaded the aging astronomer to complete his manuscript, De revolutionibus, and let him take it to a printer in Germany for publication. Though Rheticus couldn't have known it at the time, his action changed the course of civilization. Without his intervention, Copernicus's seminal work would likely have sunk into oblivion; instead, it ushered in a new understanding of the physical universe, and today is acclaimed as a landmark of scientific and cultural history. For his part, Rheticus dodged a scandal that almost ruined him and, as the founder of modern trigonometry, became a trailblazer of science in his own right.

The first popular account of Rheticus's life, The First Copernican provides a unique prism through which the dawn of the Copernican Revolution shines in fresh and illuminating ways, revealing the intense curiosity and community from which science itself took flight, as well as one man's heroic efforts to defend a new cosmology. Dennis Danielson's superb biography unveils Rheticus in his rightful role as colorful champion of new science at the threshold of the modern world.