A DECADE AGO, the Library of Congress paid $10 million to acquire the only known original copy of a 1507 world map that has been called “the birth certificate of America.” The large map, a masterpiece of woodblock printing, has been a star attraction at the library ever since and the object of revived scholarly fascination about the earliest cartography of the New World. The research has also rescued from obscurity a little-known Renaissance man, the 16th-century globe maker Johannes Schöner, who was responsible for saving the map for posterity.Five years ago, John W. Hessler, a historian of cartography at the library, published “The Naming of America,” an account of the map’s importance in post-Ptolemy geography, its disappearance for centuries and its rediscovery in a castle near the Black Forest in southwestern Germany. Now, Dr. Hessler has dug deeper into the dynamic of the years between Columbus, in 1492, and Copernicus, in 1543. Science and exploration were stretching minds to distant horizons, once unknown. Copernican astronomy was about to dislodge Earth from the center of the universe, a start to the Scientific Revolution.