The Mercator Map

Every flat map of the world has a problem: the Earth is round, and it is impossible to show a curved surface on a flat sheet of paper without stretching or squeezing some parts of it. Mapmakers must therefore choose which features to keep accurate and which to change. One of the most famous solutions was created in 1569 by the Flemish mapmaker Gerardus Mercator.

Mercator designed his map for sailors. On his map, a route that follows a single compass direction appears as a straight line. This meant that a navigator could draw a straight line between two ports, measure its angle, and then follow that compass direction across the ocean. To make this possible, Mercator had to stretch the map more and more toward the North and South Poles.

This stretching causes a well-known problem. Areas far from the equator appear much larger than they really are. On a Mercator map, Greenland looks about the same size as Africa, although Africa is actually about fourteen times larger. Because the Mercator map became so common in schools, and later in online maps, many people have a distorted idea of the real sizes of countries. For this reason, some teachers prefer other kinds of maps for showing the whole world.