TRUTH IN MAPPING
Mercator learned how to chart the globe.
by: Katherine Marsh
This winter, NASA scientists wanted to turn images from a Mars rover into a map of its landing site. They resorted to a principle developed by a Flemish cartographer nearly 500 years ago, when much of our own world was still unmapped. Although Gerard Mercator spent his entire life in one small corner of northern Europe, his skill at converting new knowledge into accu-rate maps of just about anywhere has put generations of explorers in his debt—up to the present day. “He was the world’s first modern scientific cartographer,” says Nicholas Crane, author of Mercator, The Man Who Mapped the Planet.
DRAGONS. If a map is a self-portrait of the society that draws it, those before Mercator symbolized the cloistered society of western Europe . Medieval maps showed rough versions of Europe, Africa, and Asia but then faded into nothing-ness peopled by dragons and other fantastical creatures. Says Andrew Taylor, author of the forthcoming The World of Gerard Mercator, “Medieval maps were largely subjective—they were not generally meant for travelers but for scholars or for religious purposes.
Mapmaking began to change in the mid-15th century with the rediscovery of works by the ancient cartographer Piolemy. Ptolemy introduced European map makers to a more scientific approach that relied on mathematical techniques to project the curved Earth onto a flat map . Even Ptolemy’s maps were of no use to navigators trying to chart a course, however. They distorted direction, so that a sailor follow-ing a straight line on the map had to readjust his compass bearing constantly.
Living in the age of exploration, Mercator aspired to make sense of a changing world. Born Gerard Kremer in 1512 to Flemish peasants, he took the Latin name Mercator, or “merchant,” evoking the cosmopolitan identity of this rising class. His career took a detour after he sought common ground between Lutheranism and his own Catholic faith, leading to his imprisonment by the Inquisition in 1544. After powerful friends won his release, Mercator pursued a new ambition: mapping the Earth as accurately as possible. He tackled the problem of navigation in his 1569 world map . No one is quite sure how he devised his famous projection—he may have relied on trial and error, flattening and stretching the surface of a globe. But the result was to turn the gently spiraling paths that represent constant compass headings on a globe into straight lines on a map. Although Mercator’s projection famously distorts area, making Greenland look bigger than Africa, its treatment of direction is amazingly accurate. “It was an incredible leap forward, not just for depicting the world but for moving around in it,” says John Rennie Short, a prof-essor of geography at the University of Maryland.
Mercator himself never went to sea. But he was an enthusiastic armchair traveler who corresponded with navigators and cartographers across Europe. By 1589, he had produced an entire collection of maps and coined the term “atlas.” Yet it wasn’t until after his death in 1594 that another cartographer explained how to chart a course on Mercator maps and navigators actually started using them.
Since then, Mercator’s legacy has changed the world. The first satellite map of the United States, pioneering maps of Venus and Jupiter, countless classroom maps —all are Mercator projections. “Here’s a man in the 16thcentury who drew the picture of the world that I have in my head today,” says Taylor..
U. S. NEWS & WORLD REPORT
February 23 / March 1, 2004. (Pg. 65)
Church of the Science of God
La Jolla, California 92038-3131
© Church of the Science of GOD, 1993