"Kepler" by Walter W. Bryant is a biography written in the early 20th century, specifically in 1920. This work focuses on the life and contributions of the astronomer Johannes Kepler, who is best known for his laws of planetary motion and critical advancements in the field of astronomy during the Renaissance period. The book explores the context of astronomy before Kepler's time, detailing the influence of earlier astronomers and the pivotal moments that shaped his revolutionary ideas. The narrative begins with an overview of Kepler's early life, including his struggles with health and strained family relations, before detailing his complex relationship with Tycho Brahe—one of the major astronomers of the 16th century. As Kepler joins Brahe in Prague, he gains access to an invaluable wealth of astronomical data that allows him to develop his groundbreaking theories. The central focus of the book is Kepler's formulation of his three laws of planetary motion, which overturned the long-standing Ptolemaic geocentric model in favor of a heliocentric universe. The biography further chronicles Kepler's later years, including his interactions with prominent figures, his personal hardships, and the legacy he left behind as one of the key architects of modern astronomy. (This is an automatically generated summary.)