While McLuhan himself may have been entirely unconscious of the remarkable parallel, the “date line” (or “dateline”), which he treated repeatedly in his work, is precisely what distinguishes experiential events from physical events in their “world line” (or “worldline”).

The idea of world lines originates in physics and was pioneered by Hermann Minkowski. The term is now most often used in relativity theories (i.e., special relativity and general relativity).
The world line (or worldline) of an object is the path of that object in 4-dimensional spacetime, tracing the history of its location in space at each instant in time. It is an important concept in modern physics, and particularly theoretical physics. The concept of a “world line” is distinguished from concepts such as an “orbit” or a “trajectory” (e.g., a planet’s orbit in space or the trajectory of a car on a road) by the time dimension, and typically encompasses a large area of spacetime wherein perceptually straight paths are recalculated to show their (relatively) more absolute position states — to reveal the nature of special relativity or gravitational interactions. (Wiki)

The dateline (and perhaps especially in its difference from the worldline) is critical in delineating the domain McLuhan was attempting to dis-cover for investigation: the universe of experiential events — “the infinite, interior spaces of our psyche” (Space, Time, and Poetry, 1955) comprising “the total field of information” (Great Change-overs for You, 1966).

Future posts will examine the relation of dateline and worldline in some detail. Here McLuhan’s continuing reflections on the meaning and function of the dateline will be documented in a series of passages from a 20 year period from 1951 to 1972:

The Aesthetic Moment in Landscape Poetry, 1951
Mallarmé had been led to [his] technique by an aesthetic analysis of the modern newspaper, with its static inclusiveness of the entire community of men. But the newspaper (…) as a vivisection of human interests, stands (…) behind Ulysses, with its date-line Thursday, June 16, 1904. (…) What Mallarmé and Joyce exploit in [interior] landscape technique is its power of rendering an inclusive consciousness in a single instant of perception.

Technology and Political Change, 1952
Perhaps the most significant single fact about the newspaper is its date-line. Aesthetically speaking, a week-old newspaper is of no interest at all, even though intellectually speaking it has exactly the same components as today’s paper. Aesthetically the newspaper creates an impact of immediacy and of super-realism. Metaphysically its mode is existential. Its impact is that of the very process of actualization. The entire world becomes, in this way, a laboratory in which everybody can watch the stages of an experiment. Everybody becomes a spectator of the biggest show on earth — namely the entire human family in its most gossipy intimacy. One curious aspect of the press is its willingness to be as surrealist as possible in its handling of geography and space, while sticking rigidly to the convention of a date-line. As soon as the same treatment is accorded time as space, we are in the world of Joyce’s Ulysses where it is 800 B.C. and 1904 A.D. at the same time. (…) On looking closely at the newspaper once more, it becomes evident that as a popular art form it embraces the world spatially but under the sign of a single day. The newspaper as a late stage in the mechanization of writing is handicapped in taking the next step, which occurs easily in radio and television, namely to cover not only many spaces but many times, or history, simultaneously. But even the newspaper has long felt the pressure to take this step. In juxtaposing items from Russia, India, Iran and England, it is plain that there is also a diversity of historical times that are being artificially and arbitrarily elucidated under a single date line.

Comics and Culture¹, 1953
In the one-day world of the newspapers, the comics are time-binders, making possible a continuity of experience which is not to be found in the day-by-day news itself. The news is assembled each day from the world of space. In respect to time, continuity, and memory, the newspaper hasn’t the capacities of a low-grade idiot, but in its breadth of geographic perception the press has the apprehension of a god. Local items jostle others from Iran, California, Korea, Tibet, and Italy. Yet all that holds these diverse items in focus is the date line which in effect proclaims: “This is the world in cross-section for today”. The newspaper is a highly specialized and collective art-form brought into existence by instantaneous telegraphic and radio abridgement of space.

James Joyce: Trivial and Quadrivial, 1953
The net of analogies or symbolic juxtapositions of Ulysses can (…) be seen with reference to the date line June 16, 1904. The frankly newspaperish aspect of this epic derives from the speculations and practice of Mallarmé who regarded the press as a new kind of popular poetry, collective in origin and appeal. If the trivium and quadrivium represent seven crossroads for the meeting of the various degrees and levels of reality, a page of the press is an even more complex set of crossroads, juxtaposing events representative of many times and multiple spaces under a single date line. In the press an Eskimo item will repose beside a Parisian event, the neolithic and the atomic man meet in the same flat paper landscape of the press. In the same way Ulysses is 1904 A.D. but also 800 B.C. And the continuous parallel between ancient and modern provides a “cubist” rather than a linear perspective. It is a world of a “timeless present” such as we meet in the order of objections in a Thomistic article, but also typical of the nonperspective discontinuities of medieval art in general. History is abolished not by being disowned but by becoming present. “History is now,” as Eliot sees it in Four Quartets. This “cubist” sense of the past as a dimension of the present is natural in four-Ievel scriptural exegesis and ancient grammatica. It is necessary to enjoyment of Ulysses or the Wake with its theme that “pastimes are past times,” that the popular press, popular games and ordinary speech are charged with the full historic weight of the collective human past.

Giedion-Welcker’s Klee², 1953
What became cubism [in art] was implicit in the technological conditions of reportage and news presentation more than a hundred years earlier. Implicit in the juxtaposition of many different spaces (news items) is multiplicity of times, since different areas of the world represent widely varied stages of historic acculturation. In a word the press landscape as art form is intimately linked to the technology of spatial communication and control, but is also a revolutionary medium artistically and politically. The simultaneous presentation of numerous geographic entities and historic cultures under the daily date-line creates a melting pot of the mind on a global scale.

Joyce, Mallarmé and the Press, 1954
It was Mallarmé who formulated the lessons of the press as a guide for the new impersonal poetry of suggestion and implication. He saw that the scale of modern reportage and of the mechanical multiplication of messages made personal rhetoric impossible. Now was the time for the artist to intervene in a new way and to manipulate the new media of communication by a precise and delicate adjustment of the relations of words, things, and events. His task had become not self-expression but the release of the life in things. Un Coup de Des illustrates the road he took in the exploitation of all things as gestures of the mind, magically adjusted to the secret powers of being. As a vacuum tube is used to shape and control vast reservoirs of electric power, the artist can manipulate the low current of casual words, rhythms, and resonances to evoke the primal harmonies of existence or to recall the dead. But the price he must pay is total self-abnegation. (…) By extending the technique of reporting the coexistence of events in China and Peru from global space to the dimension of time, Joyce achieved the actualized realism of a continuous present for events past, present, and future. In reverse, it is only necessary to remove the [particular] date-line from any newspaper [by adding all possible datelines] to obtain a (…) model of the universe [of experience].

Space, Time, and Poetry, 1955
[Pound’s] Cantos (…) are a flat landscape compounded of innumerable inner and acoustical spaces. (…) Even more than the Cantos, Finnegans Wake is the ultimate whispering gallery of the human psyche, its vast nocturnal caverns reverberating with every sigh and gesture of the human mind and tongue since the beginning of time. Joyce had only to remove the [particular] date-line from an ordinary newspaper in order to turn its contents into such a timeless [every dateline] whispering gallery-cum-shooting alley. But it is probably the exceptional auditory powers of Joyce and Pound that led them to acoustical manipulation of the great flat landscapes of Romantic art and the new media. To order visual images in the airy dimensions of the inner ear has been their achievement.

The Electronic Revolution in North America, 1958
More than a century ago Edgar Poe, a newspaper man, foresaw the news pattern which was to be confirmed by the telegraph. As the flow of news increased in speed and quantity, editorial or literary processing (…) became impossible. It became necessary to present a vast number of items under a single date line as a do-it-yourself kit. More and more the reader had to process the news himself. And this consequence of the electronic or instantaneous is exactly opposite to the supposed passivity which had long been the tendency of a mechanical and industrial culture in creating a consumer-oriented world. The electronic age has to become a producer-oriented world. Poe was the first to Invent art forms which met the electronic challenge by anticipation. Baudelaire and Valéry were not misguided in regarding him as a sort of Leonardo da Vinci. For he created the symbolist poem and the detective story at the same time. And both of these forms invite the reader to become co-creator. For a century the misunderstanding (…) has risen between those who look at art as a completely processed and packaged experience and those who are prepared to become co-creators in developing the experience it presents.

Myth and Mass Media, 1959
It is this instantaneous character of the information field today, inseparable from electronic media, that confers the formal auditory character on the new culture. That is to say, for example, that the newspaper page, since the introduction of the telegraph, has had a formally auditory character and only incidentally a lineal, literary form. Each item makes its own world, unrelated to any other item save by date line. And the assembly of items constitutes a kind of global image in which there is much overlay and montage but little pictorial space or perspective.

Report on Project in Understanding New Media, 1960
In the case of the newspaper, the image which is given to the reader is of the community itself. The public press presents a kind of group picture or verbal telephoto of the global human community, hour by hour. This image is made by means of a collage or assembly of dozens and even hundreds of small items much as a wire photo is achieved by means of numerous dots forming a stippled pattern. The make-up of each page must tend toward a selection in order to include a very large range of human interests. The mosaic of human interests thus achieved creates a strong impression of depth and range so that the ordinary reader is quite satisfied that he has made a real contact with the collective life of the community under the dateline indicated at the top of the page. Of course, if a reader suddenly discovers that he is reading yesterday’s newspaper, the sort of disillusionment and letdown is acute indeed. (…) By definition, no two items in a newspaper can have any connection one with the other. The only connection between any two items in a newspaper is indicated by the dateline. The fact that it happened on our planet on a given day affords the only logic or rationale…

The Medium is the Message, 1960
The items of news and advertising that exist under a dateline are interrelated only by that dateline. They have no interconnection of logic or statement. Yet they form a mosaic whose parts are interpenetrating. Such is also the kind of order that tends to exist in a city or a culture. It is a kind of orchestral, resonating unity, not a logical unity of discourse. It is not necessary to be satisfied with such a state of affairs once it is understood. Personally, I feel none of the fervor in favor of such order, as an ideal to be sought for, that is not uncommon among anthropologists. My notion is that this kind of order is inseparable from electronic technology and that auditory order quickly wipes out or brainwashes visual kinds of order by subliminal action.

The Agenbite of Outwit, 1963
The items of news and advertising that exist under a newspaper dateline are interrelated only by that dateline. They have no interconnection of logic or statement. Yet they form a mosaic of corporate image whose parts are interpenetrating. Such is also the kind of order that tends to exist in a city or a culture. It is a kind of orchestral, resonating unity, not the unity of logical discourse.

Understanding Media, 1964
Long before big business and corporations became aware of the image of their operation as a fiction to be carefully tattooed upon the public sensorium, the press had created the image of the community as a series of on-going actions unified by datelines. Apart from the vernacular used, the dateline is the only organizing principle of the newspaper image of the community. Take off the dateline, and one day’s paper is the same as the next.

Address at Vision 65, 1965
One of the mysterious things about newspapers is that the items in them have no connection except the dateline. The only connecting factor in any newspaper is the dateline, and it is this dateline that enables us to enter the world of the news, as it were, by going through the looking glass. Just as Alice in Wonderland went through the looking glass, when you enter the world of the telegraph or of the circuit, you really become involved in the information process. When you enter through the dateline, when you enter your newspaper, you begin to put together the news and you are producer. And this is a most important fact to understand about the electric time, for it is an age of decentralism. It is hard to face this. We still like to look in the rearview mirror. We still tend to think of the Electric Age as a mechanical age. It is in effect organic and totally decentralist. But the reader of the news, when he goes through his dateline apertures, enters the news world as a maker. There is no “meaning” in the news except what we make and there is no connection between any of the items except the instant dimension of electric circuitry. News items are like the parts of the symbolist structure. The reader is the co-creator, in a newspaper as in a detective story, in which the reader has to make the plot as he goes.

Great Change-overs for You³, 1966
The story line has disappeared from the recent forms of movie, whether it is the work of Fellini, or Vanderbeek, or Warhol, or Bergman. Oddly enough, the disappearance of the story line creates a much higher degree of involvement for the viewer or reader. The discovery of this means of involving the audience had been made more than a century ago by symbolist poets. Edgar Allan Poe had used the same technique in his invention of the detective story. By the use of scrambled time sequences, the detective story requires the reader to be co-author. When the telegraph entered journalism, it was quickly discovered that no story line could accommodate the total field of information produced at instant speeds. The newspaper has only one unifying factor: a dateline. There are no connections between any of the items in a newspaper, save on the editorial page which retains the story line and point of view of the book. In an electric world it is not only the story line that disappears, but also the clothes line, and the stag line, and the party line. The alternative to a story line, and to the art of connecting events, is the art of the interval. Oriental art doesn’t use  connections, but intervals, whether in the art of flower arrangement or in the poetry of Zen Buddhism. The Western world first intuited the onset of the electric age and the change-over to the art of the interval in symbolism, on one hand, and the primacy of musical structures, on the other hand. Walter Pater had observed the tendency for all the  arts to approach the condition of music, that is to say, the art of timing and of interval. James Joyce in Finnegans Wake took over the art of the interval as a means of retrieving the fantastic wealth of perception and experience that is stored in ordinary human language. As used by Joyce, the dispensing with the story line became the means of instant grasp of complex wholes…

Relation of Environment to Anti-Environment, 1966
The items in the daily press are totally discontinuous and totally unconnected. The only unifying feature of the press is the date line. Through that date line the reader must go, as Alice went, “through the looking glass”. If it is not today’s date line, we cannot get in. Once he goes through the date line, he is involved in a world of items for which he, the reader, must write a story line. He makes the news, as the reader of a detective story makes the plot.

Is The Book Dead? 1967
When everything happens at once, you have mass. It doesn’t matter how many, as long as they are all the same moment. The newspaper, the telegraph services of a newspaper, creates a mass audience in a sense that everything happens at once. When everything happens at once, you don’t have a story line. You have a dateline. In newspaper, there is no story line. The events are totally unrelated to one another except by a dateline. That is a happening. The newspaper was a happening in the fullest sense of the word, artistically, decades before the happenings began to break out in New York.

Include Me Out: The Reversal Of The Overheated Image, 1968
The world of the ear offers none of the continuity and connectedness known only to the eye. The discontinuities of the electric “space-time” had received much advance billing in the arts before Einstein. Lewis Carroll’s Alice flipped out of the hardware world of visual space, of visual uniformity and connectedness, when she went Through the Looking-Glass. But the telegraph press itself had, even earlier, reversed the pattern of the old book and editorial image. At electric speeds, a point of view is meaningless, even in a newspaper. News items are necessarily unconnected except by a date line. The newspaper mosaic has no story line. Like syncopated jazz or poetic symbolism, it is discontinuous.

From Cliché to Archetype, 1970
The newspaper has claim to be considered the first verbal form to be subjected to the shaping power of electric circuitry. The wire services had a direct impact on the nature of reporting and relating as well as upon observing events. Telegraphic speed in relaying reports had a peculiar result upon editorial practice of laying out the copy on the page. It seems to have been discovered at once that no connection was needed between any of the events recorded. The dateline was a sufficient force to create a unified field for all events whatever.

Take Today, 1972
The new information environment tends to supplant Nature, whereas the old mythic wisdom tried to explain nature. Thus modern man has to live mythically, in contrast to his ancient forebears, who sought to think mythically. Myth is the record of a simultaneous perception of effects with causes in a complementary process. It is possible to see a history of world art today in thirty seconds. A newspaper under a single date line gives you “Your World Today”.

Take Today, 1972
The poet Ezra Pound saw that the telegraph press, with its mosaic coverage of world events under a single date line, had solved the problem of creating the new poetic vision for our time.