Those interested in understanding electronic media are eventually drawn to the deep chasm that divides 'virtual reality' from 'telepresence'. The chasm has its origins in human perception, epistemology, and ontology: factors which have evolved over millions of years and been subjects of inquiry for at least two millennia. However, the shifting technological vegetation in this chasm can obscure its underlying topology. To understand the two forms and make sense of their differences, it is helpful to look at the relation between virtual reality (VR) and telepresence: it bears a similarity to the relation between painting and photography. To paraphrase Walter Benjamin, [1] the question is not whether telepresence is VR, but rather how might telepresence transform the nature of electronic art?

Virtual reality presents a simulacrum, a synthetic construction; in contrast, telepresence provides access to a remote physical environment. With telepresence, what is being experienced is distal rather than simulacral. That said, there is no universal agreement on the definitions of VR and telepresence. Unfortunately, they are sometimes used interchangeably in studies of electronic immersion. [2] However, my concern is not with the physiological and psychological issues of immersion, but with perceptions of fiction and reality.

The word 'virtual reality' was coined by Jaron Lanier in 1979. [3] Its oxymoronic richness comes from 'virtual: being in essence or effect, not in fact' (my italics).[4] Pierre Lévy [5] points out that virtual in this context should be balanced against 'actual': 'reality: actual being or existence of anything, in distinction from mere appearance; fact' (my italics). [6] For our purposes here, we can define virtual reality as the presentation of perceptual information that (1) 'realistically' simulates a fictitious 3D environment and (2) allows the user to choose a spatial viewpoint (i.e. to move through this environment). This definition is broad enough to include the popular Virtual Reality Modeling Language (VRML), the standard for 3D rendering on the WWW.

The engineering of useful telepresence is an active area of research for space, undersea, and medical applications. [7] The source of the word 'telepresence' was reported by Marvin Minsky: 'To convey the idea of these remote-control tools, scientists often use the words teleoperators or telefactors. I prefer to call them telepresences, a name suggested by my futurist friend Pat Gunkel'. [8] The word itself comes from 'tele', Greek for distance; and 'presence: the sense of proximity in time and space'. [9] Thus telepresence also has rich oxymoronic overtones. For the purpose of this article, telepresence can be defined as the presentation of perceptual information that claims to correspond to a remote physical reality. It is important to note that it is not at all obvious how to verify this claim: telepresence, like photography, can be doctored.[10]

Two examples of electronic art provide landmarks on either side of the VR/telepresence chasm. For convenience, I will refer to the primary authors although both are collaborative artworks.

Char Davies' Osmose (1995) combines high-end graphics workstations, body-mounted sensors, and a head-mounted display to create the effect that a viewer is bodily immersed in a synthetic environment. [11] Davies' lyrical images evoke an imaginary natural environment including a pond and forest. Trained as a painter, she makes striking use of sfumato effects. One of the most innovative aspects of this installation is her use of potentiometers around the chest of the 'immersant' to detect and respond to breathing. This pneumatic interface allows the immersant to navigate through the environment in a manner akin to scuba diving.

Eduardo Kac's Rara Avis (1996) places two digital cameras and robotic pan/tilt mechanisms inside the head of a fibreglass bird. [12] This telerobotic apparatus is located in an aviary filled with live birds. The cameras and robotic head are linked to a head-mounted display in a museum [13] and also to the internet via the WWW, Mbone, and CUSeeMe. [14] These links provide remote access to the bird's eye view.

Osmose is widely acknowledged as a watershed in VR as an artform. Born in Canada, Davies' aesthetics of graphics and audio combine to produce an innovative and polished result that stands in contrast to the parapatetic polygons that preceded it. Osmose has a seductive effect on its immersants. One gets the sense of being immersed in a dreamlike floating narrative. This environment was wholly invented by Davies. It is a deliberately fictional space, one does not confuse the Osmose environment with a remote physical reality.

In contrast, Rara Avis exemplifies telepresence as an artform. [15] In this work, Brazilian-born Kac raises a variety of postmodern issues. We get a glimpse from the outsider perspective of a caged rare bird. Kac's choice of location is crucial. Even if a human did enter the cage, the behaviour of the birds would be greatly affected by this trespass. Thus, the robotic cameras permit remote viewing of a rarely seen reality. Equally important, this view is accessible on the net, extending the viewing range well beyond the gallery. However, on the net, the images are 2D frames viewed on a computer monitor. On the WWW the refresh rate is approximately 1000 times slower than television. But again, I am not concerned here with immersion; my interest is in epistemological issues for which immersion is not a prerequisite. Rara Avis is pure telepresence; the cameras provide access to a live remote environment. To his credit, Kac makes little attempt at narrative and does not adorn his birdcage. It is obvious to all participants that neither the birds nor the cage are synthetic.

Contrasting Osmose with Rara Avis as artistic landmarks helps us to navigate the conceptual space between virtual reality and telepresence. Osmose presents an imaginary perspective while Rara Avis presents a 'real' yet remote perspective. This distinction is vital; a very deep chasm lies between them. And yet we cannot reach the bottom of this chasm. As we descend, our perceptions become blurred. Immersants in Osmose, through a combination of suspension of disbelief and 'trompe le corps', [16] often report a sensation on the border of reality. And some who experience Rara Avis may be sceptical: how can one know if the birds seen in Rara Avis are live or taken from a prestored library of photographs? Even if they are live, how has the robotic bird disrupted their behaviour?

The boundaries between what is seen and what is staged are increasingly blurry ... the crucial issue may not be the camera but a gnawing sense that the world itself, knowable only through imprecise perceptions, is a tissue of uncertainties, ambiguities, fictions masquerading as facts and facts as tenuous as clouds.[17]

Every technology distorts what it measures. When Galileo's telescope provided new perspectives on remote terrain, he was greeted with scepticism. Indeed, seventeenth-century lenses were highly inaccurate. The telescope, adamantly rejected by the Catholic Church, illuminated epistemological questions that set the stage for Descartes' 'dubitus ergo sum'. We are now in the Age of Telepresence, where communications, computing, and robotics provide perspectives on remote territory. We are right to doubt these new lenses. [18]

In this brief article I have argued that telepresence is a category of electronic art distinct from virtual reality. Prying these categories apart suggests critical issues in the chasm between. While VR admits to its illusory nature, telepresence claims to correspond to a remote physical reality. Thus telepresence has the capacity to introduce cult value to an electronic community fascinated by exhibition value. Our archaeological instincts draw us to this terrain between truth and fiction. By raising doubts as to whether we are experiencing reality or a carefully constructed simulacrum, telepresence has the potential to transform the very nature of electronic art.

Acknowledgments

My thanks to Char Davies, Eduardo Kac and Julia Knight who carefully reviewed drafts of this article and provided valuable feedback. Also to Scott Fisher, Peter Lunenfeld, Roger Malina, Jeff Malpas, Lev Manovich, and Michael Naimark for their insights on this topic.