Flat Maps in a 3D World: Visualizing the Past
Patricia Seed, University of California-Irvine
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.
Several projects have begun to advance this perspective. The history of geographic exploration in the United States has benefited from some early forays into 3D representation. Two websites show the elevation of the mountains that Lewis and Clark had to cross in order to reach the Pacific in the republic’s early years.2
But we have the potential to accomplish much more with these same tools; to visualize the landscape in which the historically decisive battles of Culloden, Gettysburg, and Cuzco occurred. In each case, terrain played a crucial role: the boggy marsh contributed to the Highlander’s defeat in 1746; the ridges around Gettysburg that allowed Union forces to survive until reinforcements arrived; and the steep, rocky slopes above Cuzco that nearly allowed the Incas victory over Spaniards in Peru (1533).3 Military campaigns would also benefit from such an approach. Even a single static 3D image of what the Spartans saw as they approached a Greek camp for example, allows a viewer to grasp the difficulties that battle would entail.
Such three-dimensional maps can enhance understanding and appreciation of the role that terrain and other aspects of the natural world have played in history. Providing a web forum for such images, even without a particular historical textbook or narrative, would enhance appreciation of the extraordinary as well as the seemingly ordinary human achievements in the past.
While the goal of adding topography to historical maps lies within reach, another, equally extensive use of maps among historians presents a separate set of challenges. Acquainting readers with little known places is another widespread practice of mapping that focuses on a more limited and static goal.
To try to convey a sense of uncommon geographic places, history authors usually introduce an initial map into their printed works. In North America and Great Britain, authors have observed this custom for at least a century.4 But the location of the map presents too much information too early. Encountering a novel place halfway through the text, a reader must flip to the front and then continually switch back and forth as more and more unusual names appear. This singularly annoying and time consuming activity hinders comprehension of the historical story. Most people simply abandon the effort at this point and ignore the remaining strange names and locations. As a result, readers often finish the text with a rough idea of where an episode took place but lack understanding of its immediate geographical environment. While research has long established that combining maps with narratives improves understanding and memory of both, familiarity with world geography and environments remains a casualty of this standard presentation.5
A recent attempt to remedy this annoying flipping can be found at www.gutenkarte.org. Gutenkarte has created a novel way of improving the identification of places in texts. Taking freely available e-texts from Gutenberg, it has added a flat map that pops up when a place name in the text is clicked. Identifying locales in the book of Genesis, for example, helps readers understand where important moments occurred.6 Genesis mentions “the vale of Siddim, which is the salt sea” and Gutenkarte illustrates it on a map.
While an improvement in integrating maps within a traditional text, the Gutenkarte’s current interface focuses entirely on the map. Once having opened a map, the interface leads to exploring other places on the map. Returning to read the text remains awkward. Thus the goal of full interaction between story and map, leading to the desired integration of geographic and historical learning, remains unfulfilled. While pop-up maps can readily be merged into electronic texts, the reverse approach attempted by Gutenkare, incorporating a complex story into a map, remains a significant, unsolved challenge.
Two other recently honed but competing commercial solutions will likely enjoy success among historians seeking the limited goal of acquainting readers with unfamiliar places. Both ESRI and Google, corporate giants in desktop software and the web, have created relatively accessible means for individuals to display locations on 2- and sometimes 3-D maps. Both put the creation of new maps in the hands of the individual historian allowing her to create specialized or highly detailed maps tailored to a particular subject; maps that would be uneconomical to produce in print. While both ESRI and Google can potentially improve the quality of historical place identification, both have obvious shortcomings.
Both rely upon a different mixture of proprietary and open source software. Mapping software giant ESRI produces costly software to analyze the landscape and its underlying geology, but uses freely available data. Google Earth, on the other hand, uses free software to create maps but retains copyright over the data. Furthermore, it requires that all buildings be added to maps by means of URLS, making the resulting “mashups” inherently unstable. As with all corporate software, the potential to turn both techniques into expensive, fee-based services remains a potential threat to their widespread use in humanities subjects.
However, from the standpoint of improving visualization (rather than place identification), both ESRI and Google Earth are limited by taking the “God’s eye” or overhead view of terrain. At present, neither makes it easy to present a human’s view toward the sky. Traditional CAD tools such as AutoCAD still provide better models for human scale perspectives. Even Google’s recent purchase of the very basic CAD program Sketch-Up has only managed to allow the introduction of a static image without altering the basic perspective of the viewer. A better means of integrating this human-centric perspective into 3-D maps is a development worth waiting for.
While no readymade solution to this latter problem exists, advances in three-dimensional visualization have the potential for shifting identifications from passive to active, and creating new representations of an increasingly important historical subject, the history of human interconnection with the environment. Going beyond human interaction with static landforms, these emergent methods have the potential to incorporate a model of dynamic human activity with a changing environment.
Some historical projects on a geological time scale have already started to address these issues. The history of migrating drainage systems, often buried beneath subsequent accumulations of silt, can explain the appearance and movement of the earliest human settlements. For example, histories of the shifts in river beds have significantly altered our understanding of the patterns of human settlement in China.7
In other areas, an as yet unrealized potential exists and is within reach. The relatively recent progress in three-dimensional mapping of the sea’s underwater shape allows us to understand how and why certain patterns emerged in shipping and sometimes even the reasons for the deadly fate of certain vessels. Using the software program AVS,8the Australian Navy Hydrographic Service developed a superbly detailed image of the sea floor off the continent’s coast. The Service conceived this map with the aim of identifying safe shipping channels, and protecting the fragile Great Barrier Reef from damage by careless pilots. Yet these same maps can be used to understand why a steel steamer carrying a large cargo of gold broke up off the coast of Queensland in 1875, or actively comprehend the choices Captain Cook made as he navigated through the Great Barrier Reef in 1770.
Since human relationships with the environment usually involve constant change and adaptation on both sides, only similarly dynamic three-dimensional visualizations have the potential for portraying that interactive past of humans and their environments. Increasingly complex, three-dimensional computer visualization in meteorology and oceanography has vastly improved our knowledge and understanding of complex dynamic processes such as weather and ocean currents. These models contain an unrealized potential to contribute to understanding why agricultural settlements emerged in one area, while a pastoral economy developed nearby. They can also show how environmental factors such as wind and water patterns might have influenced where people near a coast would have chosen to reside. Their potential also exists for understanding other interactions with the environment.
Several obstacles hamper the task of conveying the complexities of ocean going travel before the age of steam and the screw propeller. Boats do not climb up and down as people do on land, unless of course they are heading to the bottom of the sea and hence to the end of the story. At sea, winds blow from 360 degrees, buffeting ships sideways; boundary currents pull vessels in giant curving arches away from the edges of oceans and towards their center. The frailty of life at sea, the continual vulnerability to the natural world, remains difficult to convey through the customary smooth depictions of the surface of the sea on maps.
More complex visualizations offer the opportunity to portray three-dimensional relationships including the movement of ships in nearly all directions. Representing the dynamic dimension of humans operating in space would allow us to understand historical events. Beyond this, such representations have the potential to allow denizens of the present to more closely identify with the human fate of long-deceased individuals from around the globe.
One of the most shameful episodes of modern history occurred with the forced mass deportations of Africans on board slave ships destined for Europe, the Atlantic Islands, and eventually the Americas. As the earliest slaves boarded ships bound for harsh lives in an unknown world, they would have seen the coast of Africa for the last time. In order to re-envision these last glimpses of Africa, which likely would have remained with them, I have been combining the historical information from the first maps of the region during the fifteenth century, with contemporary data on the heights of hills and the paths of rivers to create an image of West Africa as it would have been seen for the last time.9 Employing additional information on the patterns of winds and currents, I can also depict the course most likely taken by a fifteenth-century sailing ship, thus recreating the angle and speed at which the African coast would disappear from sight. Such re-creations will allow scholars to see how different the fifteenth-century landscape appeared, and permit others to empathize with the human dimension of the tragedy for themselves and others.
Recent advances in scientific, three-dimensional visualization can significantly improve our ability to immerse ourselves in the geographic environment of a faraway past and a culturally distinct environment. Because of their accuracy, these models are likely to receive a warm welcome in history. And these representations, especially the dynamic ones, remain far preferable to those visualizations more familiar to this generation of students, those dreamed up in the game studios of Blizzard, Ensemble or Fireaxis.
2 The US Geological Survey’s site (www.usgs.gov/features/lewisandclark.html ) shows an elevation map of the western United States that offers a tantalizing glimpse of the difficulties Lewis and Clark faced. A hard to access map in the David Rumsey collection (www.davidrumsey.com/) illustrates the steep terrain with an overlay.
3 Culloden (1746) was the last major battle fought on English soil, destroyed Stuart pretensions to the throne, and many of the Scottish highland clans.
4 Only English language textbooks costing hundreds of dollars can one find maps distributed throughout the book. Maps rarely appear in Spanish historical texts, and appear erratically in histories composed in the remaining Western European languages.
5 Kulhavey, R., Stock, W. A. “How Cognitive Maps Are Learned and Remembered,” Annals of the Association of American Geographers 86, no. 1 (1996): 123-45. links.jstor.org/sici?sici=00045608%28199603%2986%3A1%3C123%3AHCMALA%3E…
7 Taha, P. “Fluvial Response to Base Level Change: A Case Study of the Brazos Incised Valley,” Unpub. Phd. Dissertation, Rice University 2006; Peter Bol’s China Historical GIS, a major study of the relationship of settlement to the historical river pathways in China.
9 The project is being generously supported by the American Council of Learned Societies and the National Endowment for the Humanities’ Digital Initiative Start-Up Grant Program.