Photo: David Stuart; Retouching: Smalldog Imageworks

There are two ways to tell the tale of one Sarah K. Dye, who lived through the Union Army's siege of Atlanta in the summer of 1864. One is to set up a plaque that narrates how she lost her infant son to disease and carried his body through Union lines during an artillery exchange, to reach Oakland Cemetery and bury him there.

The other is to show her doing it.

You'd be in the cemetery, just as it is today, but it would be overlaid with the sounds and sights of long ago. A headset as comfortable and fashionable as sunglasses would use tiny lasers to paint high-definition images on your retina—virtual images that would blend seamlessly with those from your surroundings. If you timed things perfectly by coming at twilight, you'd see flashes from the Union artillery on the horizon and a moment later hear shells flying overhead. Dye's shadowy figure would steal across the cemetery in perfect alignment with the ground, because the headset's differential GPS, combined with inertial and optical systems, would determine your position to within millimeters and the angle of your view to within arc seconds.

That absorbing way of telling a story is called augmented reality, or AR. It promises to transform the way we perceive our world, much as hyperlinks and browsers have already begun to change the way we read. Today we can click on hyperlinks in text to open new vistas of print, audio, and video media. A decade from now—if the technical problems can be solved—we will be able to use marked objects in our physical environment to guide us through rich, vivid, and gripping worlds of historical information and experience.

The technology is not yet able to show Dye in action. Even so, there is quite a lot we can do with the tools at our disposal. As with any new medium, there are ways not only of covering weaknesses but even of turning them into strengths—motion pictures can break free of linear narration with flashbacks; radio can use background noises, such as the sound of the whistling wind, to rivet the listener's attention.

Along with our students, we are now trying to pull off such tricks in our project at the Oakland Cemetery in Atlanta. For the past six years, we have held classes in AR design at the Georgia Institute of Technology, and for the past three we have asked our students to explore the history and drama of the site. We have distilled many ideas generated in our classes to create a prototype called the Voices of Oakland, an audio-only tour in which the visitor walks among the graves and meets three figures in Atlanta's history. By using professional actors to play the ghosts and by integrating some dramatic sound effects (gunshots and explosions during the Civil War vignettes), we made the tour engaging while keeping the visitors' attention focused on the surrounding physical space.

We hope to be able to enhance the tour, not only by adding visual effects but also by extending its range to neighboring sites, indoors and out. After you've relived scenes of departed characters in the cemetery, you might stroll along Auburn Avenue and enter the former site of the Ebenezer Baptist Church. Inside, embedded GPS transceivers would allow the GPS to continue tracking you, even as you viewed a virtual Reverend Martin Luther King Jr. delivering a sermon to a virtual congregation, re-creating what actually happened on that spot in the 1960s. Whole chapters of the history of Atlanta, from the Civil War to the civil rights era, could be presented that way, as interactive tours and virtual dramas. Even the most fidgety student probably would not get bored.