The first definition of "time" in the Oxford English Dictionary is "a space or extent of time" (OED). The first definition of "space" is "denoting time or duration" (OED). These circular definitions demonstrate the congruity between time and space as concepts. While long related through motion (cf movement), the congruity of "time" and "space" reaches its scientific apotheosis in the early twentieth century with the single concept of "space-time" in physics and mathematics. Before Albert Einstein and Hermann Minkowski conceived of "space-time," time and space were aligned as separate but interdependent media. Time and space in and of themselves are media in that they fulfill the Oxford English Dictionary's definition of "medium" as "pervading or enveloping substance; the substance or 'element' in which an organism lives; hence ... one's environment, conditions of life" (OED 4b). Time and space are also elements that fundamentally determine and affect multiple forms of media. Conversely, media transform the human experience and perception of time and space.
In The Art of Memory, Frances Yates elucidates a classical example of the perceptual affects of time and space through media. The medium of memory utilizes both time and space. "Artificial memory," a mnemonic technology, was used to remember a speech as it unfolded in time through the media of architecture. [see memory, (2)] The speech was mapped onto specific familiar places or "loci" through which the orator navigated in his or her mind. In "artificial memory," the temporal and the spatial were inextricable.
The Enlightenment ushered in new concepts of time and space to match its championing of scientific thought, empiricism, and rationality. The work of French mathematician and philosopher René Descartes (1596-1650) posits understanding as existing in the mind alone and casts doubt on experience produced through corporeal sense perception. Descartes' conception of time and space reflects this primacy of the mind. Descartes maintains that space is infinite and unlimited, and that time is the means with which the human mind accounts for duration (Trusted 69-70). Scientist Isaac Newton's (1642-1727) theories of mechanics are postulated on the ideals of absolute space and time. Due to instabilities in the earth's movement, human beings necessarily depend on "relative time," although an absolute time outside of this relativity exists. Likewise, absolute space exists because, while objects may be moved in relation to each other, space itself cannot be moved (Trusted 98-100). In 1766, German writer Gotthold Ephraim Lessing's Laocoön applied the Enlightenment sensibilities of Newton and Descartes to media theory. Lessing states that pictorial representation (see drawing and painting) should strive for spatial purity and that poetry must represent time, or the changing moment. Lessing's distinction between media as privileged representations of either space or time, and these divisions of time and space as theoretical absolutes in the Enlightenment project, were undermined in the early twentieth century by Albert Einstein's theory of relativity of 1905 and 1916, and Hermann Minkowski's formulation of a non-Euclidean geometric space.
According to Einstein, space and time are relative to the observer. They are continuous only within the coordinate system in which they are operating. Therefore, multiple types of "space-time" are conceptually possible outside of the "space-time" experience of human beings (Nerlich 1-11). In 1907, German mathematician Minkowski published Space and Time , a text that posited a four-dimensional space, with time as the fourth dimension. Minkowski was a crucial influence on Einstein's revision of the theory of relativity and the further definition of his own concept of "space-time" as a single entity rather than two separate entities (Nerlich 1-11). Einstein's and Minkowski's conceptions of space radically transformed the media of visual arts and literature. As Linda Dalrymple Henderson notes in The Fourth Dimension and Non-Euclidean Geometry in Modern Art, modernist movements in the visual arts became concerned with the representation of four-dimensional spatial realities as determined by time. From Cubism, which still maintained a figurative approach, to the abstractions of Russian suprematism and De Stijl, modern art attempted to depict and form changing spatial and temporal realities. Likewise, as Joseph Frank proposes in The Idea of Spatial Form , modernist writers intend their work to be read as a distinct moment in time as opposed to a chain of events. Lessing's categories had switched sides to the pictorial representation of time and the literary representation of space.
In the late 19th and early 20th century, the development of the film medium was another radical influence on changing perceptions of space and time. Film produced the movement through time of photographic recordings of space. French film theorist André Bazin's What is Cinema? argues for an utter realism in cinema justified by film's unique ability to represent time itself. "The cinema is objectivity in time ... Now, for the first time, the image of things is likewise the image of their duration, change mummified as it were" (Bazin 14-15). In his book Gramophone, Film, Typewriter, Friedrich Kittler equates this realization of images moving through time with Lacan's imaginary, while the materiality of the film stock itself and each individual frame belongs to the Lacanian real (Kittler 122). (see symbolic-imaginary-real) Film's projection produces an illusion of spatial depth and movement through time in the viewer. Like perspective in painting and composition within the photograph , the two-dimensional image on the screen is made perceptually three-dimensional and identifiable through the placement of objects and light patterns (Bordwell and Thompson 176). In the 1970s, French films theorists such as Christian Metz and Jean-Louis Baudry likewise associated film with the Lacanian imaginary. These 'apparatus theories' compared the sense of empowerment that emerges in Lacan's mirror stage with the illusions of control over space and time which the cinema, particularly classical Hollywood cinema, produced.
Other so called "time-based" media that construct similar illusions of three-dimensional space through different technologies such as television's cathode ray tube, video's tape encoding, and digital video's digital codes have emerged since the development of film (although pre-filmic media such as writing are also dependent on movement through time). In addition, computer technologies and the common use of personal computers since the 1990s have effected further change in the presentation of time and space in media. N. Katherine Hayles points out in her essay "The Condition of Virtuality" that time lags produce the effects of three-dimensional space on the computer screen. Hayles writes, "three-dimensional representations take many more [time] cycles [which are determined by the computer's internal clock] than do two-dimensional maps. (see virtuality) Hence the user experiences the sensory richness of three-dimensional topography as a lag in the flow of the computer's response" (90). Interestingly, three-dimensional spatial experience, called into question by certain movements in modern art, remains the dominant form of spatial replication in cinema, television, video, and computers. The sense of control over time and space in cinema examined by French apparatus theory seems eminently applicable to the three-dimensional worlds of computer video games in which the player controls the movements of an avatar through space and time as simulated on the television monitor or computer screen.
In addition to the perceptual accommodations to space and time in media such as television, film, and computers, theorists of the 'postmodern,' the period of the late twentieth and early twenty-first centuries, postulate that experiences of time and space outside individual media have become increasingly compressed. In The Condition of Postmodernity, geographer David Harvey argues that a "time-space compression" initiated through social factors such as economic globalization, the quick dispersal of information through communications networks, and the accelerated pace of consumption dialectically produces and is produced by a "postmodern" sensibility with deep socio-economic roots. In Understanding Media , Marshall McLuhan describes a similar process as "implosion" as people are more closely unified through networks in the electronic age. This unification through implosion, for McLuhan, produces a positive sensory connection that allows for a "global village" to emerge. "The immediate prospect for literate, fragmented Western man encountering the electric implosion within his own culture is his steady and rapid transformation into a complex and depth-structured person emotionally aware of his total interdependence with the rest of human society" (McLuhan 50). Harvey, on the other hand, is less sanguine about our ability to adapt to postmodern shifts in time and space. "There is an omnipresent danger that our mental maps will not match current realities" (Harvey 305).
Media open and shape our experiences of time and space. Experientially, if not literally, human beings can operate on radically different time-space coordinates through media from painting to writing to film. Media also shape time and space experienced in "daily life" from forming space through architectural intervention to standardizing time to enable trade and communication. Theories of time and space, whatever their diagnosis, must account for the radical physical restructuring of time and space which has taken place over the last century. Technological developments in communications media (from the telegraph to the telephone to email), travel (the airplane), and the dissemination of information (television to the internet) are perceptually reducing and conflating the lived experience of time and space, as discussed by Harvey and McLuhan. Transformations in the perceptions of time and space form an understanding of the world. The purity of poetry and painting as posited by Lessing were Enlightenment ideals just as the attempt to represent the fourth dimension of time was a modernist goal. An understanding of time and space in the late-twentieth, early-twenty-first century is determined by the media which structure and augment lived space and time. The French philosopher Henri Bergson, in the early twentieth century, formulated the notion that time is always in a state of flux, or becoming, through changes in space, and that fixed concepts of being are patently false. "Thanks to the third dimension of space, all the images making up the past and future are ... not laid out with respect to one another like frames on a roll of film ... But let us not forget that all motion is reciprocal or relative: if we perceive them coming towards us, it is also true to say that we are going towards them" (Bergson 142). Absolute time and space are historical products as are the concepts of "time-space compression" and "implosion," but their mediated and mediating reality is nonetheless crucial to the formation of lived experience.