Flat maps conclusively proved their worth to the 3D world more than 500 years ago. In 1569 a mapmaker named Gerhard Mercator created a plane surface allowing a navigator to plot an ocean going voyage as a straight line. At a time when sailors spent months onboard ships, the ability to plan (and record) a journey on a sheet of paper or vellum proved invaluable. Nor has the 2D map become outmoded by newer means of travel. In the twentieth century, airplane pilots discovered that another, slightly differently designed flat map permitted them to find the shortest flying distance between two points.
The 2D map has thus allowed humans to journey where no one had ventured before. Magellan sailed around the world guided by nearly half a dozen skilled mapmakers, and James Cook journeyed through the South Pacific with the aid of equally flat navigational charts. Eventually, the ability to travel led to regularly scheduled transportation and from that to the growth of global commerce and communication. No shortage of good reasons exists to celebrate the human achievements that flat maps made possible.
But when trying to communicate knowledge of the past, to grasp actions that occurred long ago and far away, two-dimensional surfaces only limit the degree of comprehension. For example, the terrain has historically presented obstacles for finding the best places for concealment and observation, and the preferred avenues of approach during military skirmishes. Looking at a flat map with small circles designating locations of attacks leaves us unable to fully grasp the role of the large silent actor in many campaigns, the countryside. Lacking three-dimensional representation of the terrain, a full-fledged appreciation of the difficulties presented in conflicts remains out of reach.
But such limitations are not restricted to portrayals of combat. When seeking to understand how people migrated throughout the world, flat maps leave out the reasons for the paths they took. When inhabitants of Tibet migrated from plateaus 14,000 feet high, they swerved to avoid even higher mountains and, upon reaching the lowlands of tropical Burma, sidestepped river gorges 10,000 feet deep.1 Flat maps fail to do justice to either the difficulties of descending the Himalayas or the hazards of the paths migrants took in northern Burma. With only a flat map, it remains hard to understand the level of courage they displayed and degree of difficulty these migrants endured.
Despite their considerable limitations, two-dimensional maps predominate today in the study of the past; depicting the historical movement of peoples, the paths of long-forgotten sailing vessels, and the position of opposing forces in battle centuries ago on flat surfaces. Yet the capacity to change this approach already exists.
Existing technologies could create many of these three-dimensional images for historical images. Digital elevation models (showing the height of landscape features) are available freely for nearly every corner of the earth. Including this information, even on a flat map, would lead to a greater appreciation of the physical obstacles to survival that humans have faced in times of both peace and war–the unexpected mountains and gorges that thwarted their search for better places to live or to hide.