It took centuries and the courage of several scientists to give correct answers to fundamental questions about the Universe. Nicolaus Copernicus in his treatise “On the Rotation of the Celestial Spheres”, Galileo Galilei in his “Dialogue Concerning the Two Chief Systems of the World”, Johannes Kepler in his “Harmony of the World”, Isaac Newton in his “Mathematical Principles of Natural Philosophy” and Albert Einstein in his numerous articles on the principle of relativity opened the eyes of contemporaries to how the firmament works and what happens beyond the visibility of a telescope. It was these works and these ideas that changed the direction of scientific thought, and the earlier ones marked the transition from the Middle Ages to the modern era. Excerpts from the original texts are supplemented by comments by Stephen Hawking, who also compiled a biographical sketch for each of the authors so that the reader can trace the global evolution of astrophysical views and train of thought of a private genius.