Finding Out What the Past Smelled Like

Augmented reality could change the way we understand—and experience—history.

It was the smell that hit me first, a heady mixture of roasting meat, woodsmoke, and farmyard manure. Nearby I could hear a low murmured conversation—but the words were muffled and unclear. I could see piles of stones clustered across the edge of a bleak Cornish moorland hillside and an ominous raincloud gathering over the closest hill.

But there were no houses, no people, and no welcome barbecue. With freezing fingers I held up my iPad, viewing the landscape through the camera feed. I saw the icons change as the GPS recognized my position and, as if by magic, the houses began to appear, each one loading onto the screen, materializing in position above the round piles of prehistoric stone. Using the screen as a guide, I picked my way through the virtual settlement, walking around the houses as if they were real. As I walked toward one, the sound of the conversation got louder, and I could hear the crackling of a fire. The smell of the meat got stronger, filling my nostrils and making my mouth water. I reached the door, and looked inside, expecting to feel the heat of a welcome fire and the shelter of the roof. But all I saw was a rendered straw floor. And as I lowered the iPad, I saw again a pile of stones no higher than my knee, arranged in a circle with a gap for a doorway. The raincloud is getting closer.

This was my experience during testing a prototype augmented-reality application I designed to allow an embodied exploration of past landscapes. I built the system using low-cost materials and cheap or free software. I’m an archaeologist, and I am particularly interested in finding out what it was like to live in the past. (I'm calling the app Dead Men’s Eyes, a name that comes from a short story by Montague Rhodes James in which a man discovers a pair of old binoculars made by an eccentric antiquarian. When he looks through them, he is shown a world that no longer exists, and sees grisly scenes from the past.)

The past is dead, a foreign country where they do things differently. I experimented with augmented reality as a way to try bring me closer to experiencing what life was like in the past. Augmented reality is a way of merging the real world with virtual objects. It normally involves overlaying virtual objects onto live video feed from either a web camera, a head-worn display, or a mobile device. Many of the major technology companies (with the notable exception of Apple) have now produced such headsets—such as Google Glass or Microsoft's HoloLens. Some augmented-reality applications require the use of a physical marker to launch the experience—such as advertising interfaces that allow you to “drive” a car before buying it—whereas others work by locating your device using the embedded GPS and compass, such as Google’s worldwide roaming augmented-reality game Ingress.

The system I developed used my iPad’s GPS to pinpoint my location as I stood in the remains of a prehistoric settlement on the side of Leskernick Hill, in the middle of Bodmin Moor in Cornwall, at the extreme southwest of the United Kingdom. Leskernick Hill is the site of a Bronze Age (2500-800 B.C.) tin-mining village. Although today Cornwall is mainly a destination for summer tourism and surfers, it was, until the 19th century, one of the world’s major tin suppliers. Tin is the vital ingredient (along with copper) used to make bronze, hence the site’s importance during the Bronze Age. We know that Cornish tin was widely traded across northern Europe and the Mediterranean.

Back in 2015, and me standing on the grassy hillside where the tin-miner’s huts once stood: Once the app had my location, I was able to hold up the iPad and look through the video screen. Using a mixture of the Unity3D gaming engine and Vuforia’s augmented reality technology, the app overlaid reconstructions of the houses in their correct location and perspective relative to where I was standing. As I turned, the virtual houses updated their position and I could see the whole village.

Seeing a reconstruction of the village that can be physically explored when you are standing in the real location is a visceral experience and, for me, comes pretty close to a time machine. However, most current augmented reality technology is almost entirely based around the visual experience to the detriment of the other senses. I wanted as many of these other senses to play a part in my complete experience, if possible. So I included aural augmented reality in the form of a pair of AfterShokz bone-conducting headphones that played 3-D geo-located sounds as I walked around the site—such as the murmured conversation taking place in a hut (occluded by the virtual walls, and using freely downloadable sound effects), and the crackling of the hearth fire. By using bone-conducting headphones that don’t obstruct the ear canals, I could still hear the real world: the sounds of the birds, the sheep in the distance, and wind in the trees. I also developed what I'm calling Dead Man’s Nose, built using an Ardunio microcontroller and a set of small computer fans each with its own specific phial of historical odor (chosen from the plethora of wonderful and weird smells available at this online fragrance shop). The device is worn around the neck and the associated app is programmed to produce a specific smell depending on your geographic location, with a fan that gently wafts it in the direction of your face. (As the Dead Man’s Nose is still in a prototype phase, the pre-emptive whirring of the fans when a smell was about to be wafted was a little anachronistic for the Bronze Age—but the effect the aroma had on me was no less powerful for that.) So now I not only saw the houses, but I heard the muffled conversations and I even smelled the fires and the cooking meat inside.

The whole experience was being overlaid on the real-world, using the actual location and remains of the prehistoric village as a canvas on which to conjure the images, sounds, and smells of the past. It is not a static reconstruction, it can be moved through and updated and changed. Different people can suggest different interpretations of the same site, and the different periods of the site can also be reconstructed, allowing movement not only through space, but also through time.

The augmented reality revolution is, for now, being led by the technology and by big corporations. The majority of such applications being developed are used by advertisers or marketers—leading us ever closer to a Gibsonian dystopic future of all pervasive virtual adverts being beamed directly into our retinas. However, the potential of augmented reality for many fields is only just beginning to be explored, and as new hardware and software is produced the experiences can only get better. For example, as shown in a recent TED talk by the leading AR evangelist Helen Papagiannis, augmented reality has the potential to be an incredible storytelling medium. As an archaeologist, I am interested in telling the stories of past people, but artists, writers, journalists, historians, anthropologists, and anyone who has a story to tell and wants to tell it linked to actual locations or physical items has a stake in the future of augmented-reality devices.

Earlier this month, we saw the launch of Detour, an app that offers location-based audio stories tied to walks around San Francisco. Engineers at the Library of Congress have said they’re interested in developing similar experiences for visitors. We should be driving the direction of its technological development in ways that will be of real cultural benefit to the people of today and the future, rather than just waiting for the inevitable day when it will be used to sell us more stuff we don’t want or need.

For now, I’m heading back in time again, to a windy Bronze Age hill in Cornwall to walk among the tin-miners awhile. The future looked, sounded, and smelled pretty good back then.