McLuhan, along with everybody else in his time, regularly invoked Einstein.  The suggestion here is that, uniquely, McLuhan may have found a way to apply relativity and topology to the universe of human experience.  This was his answer to the question of how to maintain values which had taken root in a literary environment — like private identity and individual rights and democracy and religious belief — when that environment was dissolving in the electric era. For such a theory would allow the translation of values across experiential divides: “seeing our old literary culture in the new plastic [or electric] terms” would “enable it to become a constitutive part of the new culture created by the orchestral voices and gestures of new media.”¹ 

 McLuhan himself attributed the initial dis-covery of the idea to Joyce:

Siegfried Giedeon has given exact procedures for how the modern painter or poet should conduct himself in the company of scientists: Adopt and adapt their discoveries to the uses of art. Why leave this solely to the distortions of the industrialist? [Just as] Newton revolutionized the techniques of poetry and painting [through his optics, so] Joyce encompasses Einstein but extends his (…) formula to the entire world of language and consciousness. (‘New Media as Political Forms’, Explorations 3, 1954)

Dis-covering a “formula” that would cover “the entire world of language and consciousness” was possible for McLuhan, however, only when he learned how to translate himself across that “entire world”.  In fact he had long applied this demand to others.  Already in 1944 he had complained in a letter to Walter Ong and Clement McNaspy that F.R. Leavis, his erstwhile intellectual model, was unable “to grasp current society in its intellectual modes”:

the trouble with Leavis is that his passion for important work forbids him to look for the sun in the egg-tarnished spoons of the daily table. In other words, his failure to grasp current society in its intellectual modes (say in the style of Time and Western Man or Giedion’s Space, Time and Architecture) cuts him off from the relevant pabulum.²

This demand for potential identification with any and all human experience was central both to McLuhan’s intellectual trajectory and to his religious persuasion. Over the next decade (1944-1954) he would come to see that the rejection of any aspect of human experience amounted to gnosticism — to the claim that God’s power was limited, and/or that God’s goodness was limited, in such a way that aspects of reality were not as they ought to be. Such a value judgement, he would realize, necessarily privileged some perspective and this, in turn, both implemented a central procedure of the dissolving Gutenberg galaxy and cut off access to the possibility of a general relativity theory of “the entire world of language and consciousness”. 

It is no accident that his struggles with gnosticism came at just the time that he was also struggling intellectually to understand non-Gutenberg experience, aka “acoustic space”, from within. 

McLuhan had to come to valorize acoustic space as much as visual space in order then (and only then) to focus experience as the range of the ratio of the ‘visual’ and the ‘acoustic’ as modulated by ‘touch’. Thanks to Ted Carpenter‘s work with the Inuit, and Carlton Williams‘ work on “auditory space” with E.A. Bott,  and to his own on-going absorption with Finnegans Wake (all of which require much future consideration), McLuhan came in the second half of the 1950s to perceive, through a new appreciation of “acoustic space”, how decidedly he himself had been visually biased even as late as 1954.³

This new appreciation of acoustic experience and of its fundamental differences from visual experience emerges in reference to Einstein in the 1960 version of ‘Acoustic Space’ (in the anthology, Explorations in Communication), a reworking by McLuhan and Carpenter of Williams’ earlier essay of the same name in Explorations 4.

Most people feel an obscure gratitude to Einstein because he is said to have demonstrated that “infinite” space has a boundary of some kind. The gratitude flows, not because anyone understands how this can be, but because it restores to visual space one of its essential elements. The essential feature of sound, however, is not its location, but that it be, that it fill space. We say “the night shall be filled with music,” just as the air is filled with fragrance; locality is irrelevant. The concert-goer closes his eyes. Auditory space has no point of favored focus. It’s a sphere without fixed boundaries, space made by the thing itself, not space containing the thing. It is not pictorial space, boxed in, but dynamic, always in flux, creating its own dimensions moment by moment. It has no fixed boundaries; it is indifferent to background.

Two years later in The Gutenberg Galaxy McLuhan described the coming and the going of the visual world in further reference to Einstein:

But the absurdity of speaking of space as a neutral container will never trouble a culture which has separated its visual awareness from the other senses. Yet, says Whittaker (p. 100 [Space and Spirit, 1948]) “in Einstein’s conception, space is no longer the stage on which the drama of physics is performed: it is itself one of the performers; for gravitation, which is a physical property, is entirely controlled by curvature, which is a geometrical property of space.” With this recognition of curved space in 1905 the Gutenberg galaxy was officially dissolved. With the end of lineal specialisms and fixed points of view, compartmentalized knowledge became (…) unacceptable (…). And it has been the effort of this book to explain how the illusion of segregation of knowledge had become possible by the isolation of the visual sense by means of alphabet and typography.⁴  Perhaps it cannot be said too often. This illusion may have been a good or a bad thing. But there can only be disaster arising from unawareness of the causalities and effects inherent in our own technologies. (253)

 In Understanding Media he again recurs to Einstein in two important contexts:

Lewis Carroll took the nineteenth century into a dream world that was as startling as that of Bosch, but built on reverse principles. Alice in Wonderland offers as [its contasting] norm that continuous time and space that had created consternation in [Bosch and] the Renaissance. Pervading this uniform Euclidean world of familiar space-and-time, Carroll drove a fantasia of discontinuous space-and-time that anticipated Kafka, Joyce, and Eliot. Carroll, the mathematical contemporary of Clerk Maxwell, was quite avant-garde enough to know about the non-Euclidean geometries coming into vogue in his time. He gave the confident Victorians a playful foretaste of Einsteinian time-and-space [when Alice’s Adventures in Wonderland was published in 1865, decades before] (…) relativity theory in 1905 announced the dissolution of uniform Newtonian space as an illusion or fiction, however useful. Einstein pronounced the doom of continuous or “rational” space, and the way was made clear for Picasso and the Marx brothers and MAD. (UM 162-163)

WHY THE TV CHILD CANNOT SEE [LINEARLY] AHEAD: The plunge into depth experience via the TV image can only be explained in terms of the differences between visual and mosaic space. Ability to discriminate between these radically different forms is quite rare in our Western world. It has been pointed out that, in the country of the blind, the one-eyed man is not king. He is taken to be an hallucinated lunatic. In a highly visual culture, it is as difficult to communicate the non-visual properties of spatial forms as to explain visuality to the blind. In the ABC of Relativity Bertrand Russell began by explaining that there is nothing difficult about Einstein’s ideas, but that they do call for total reorganization of our imaginative lives. It is precisely this imaginative reorganization that has occurred via the TV image. (UM 332-333)

A number of critical insights may be noted in these passages:

• Einstein’s ideas play a role in history about history 
• extending relativity theory to human experience requires the specification of ‘visual’ and ‘acoustic’ space as “radically different forms” — ie, not (or not only) of senses as found in experience, but as co-variable elementary factors within a topological equation about experience
• certain axial periods in history like that of fifth century BC Greece, the Renaissance and the birth of the electric era (in which we are still immersed) give important information about the valence (aka, the measure of combining power) of such experiential forms

In ‘Television in a New Light’ (1966), Einstein’s theories are used to illustrate the “momentous” explosive power of “electric speeds”:

The [Gutenberg] public is a world in which everybody has a little point of view and a little fragment of space all his own, private. In the [electric] mass audience everyone is involved in everybody and there is no fragmentation and no point of view. The mass is a factor of speed, not of quantity. This is literally and technically true. The mass is created by speed and everyone reading the same thing or doing the same thing at the same time. It is like Einstein’s idea that any kind or particle of matter can acquire infinite mass at the speed of light. Any minute, trite bits of news acquires infinite potential at the speed of electricity. Anything becomes momentous at electric speeds. And a mass audience is an audience in which everyone experiences and participates with everybody and in which nobody has a private identity. So the psychiatrist’s couches today are groaning with the weight of people asking, “Who am I? Please tell me who I am.” There is no identity left. At electric speeds nobody has a private identity. Don’t ask whether this is good or bad. It is an inevitable function of electric speeds.

In the later 1960s McLuhan continued to bring Einstein together with Alice:

Lewis Carroll looked through the looking-glass and found a kind of space-time which is the normal mode of electronic man. Before Einstein, Carroll had already entered that very sophisticated universe of Einstein. Each moment for Carroll had its own space and its own time. Alice makes her own space and time. Einstein, not Lewis Carroll, thought this was astonishing. (Stern Interview, 1967)

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. (Include Me Out, 1968)

Leaving aside the posthumous Laws of Media (requiring separate treatment), it is in Take Today (1972) that Einstein receives most frequent mention from McLuhan:

As the electric environment increasingly engulfed the old Greek “Nature,” it became apparent that “Nature” was a figure abstracted from a ground of existence that was far from “natural.” Greek “Nature,” which sufficed until Einstein, excluded most of the chaotic resonance of the great Sound-Light Show of existence itself. Most of the pre-Socratic magic and ESP and all the Oriental and “Primitive” Natures were pushed into the “subconscious.” Civilized man exists by dumping most of his experience into that convenient bin. Electric man has discovered that it is his major resource centre. (TT 7)

Once science went through the vanishing point into acoustic or resonant space, (…) economists were left on the wrong side of the looking glass, because they were mostly unable to make what Bertrand Russell cited (on the first page of his ABC of Relativity) as the indispensable preliminary act needed for grasping Einstein: “What is demanded is a change in our imaginative picture of the world…” (TT 69)

There are, in fact, no connections in the material universe. Einstein, Heisenberg, and Linus Pauling have baffled the old mechanical and visual culture of the nineteenth century by reminding scientists in general that the only physical bond in Nature is the resonating interval or “interface”. Our language, as much as our mental set forbids us to regard the world in this way. It is hard for the conventional and uncritical mind to grasp the fact that “the meaning of meaning” is a relationship: a figure-ground process of perpetual change. The input of data must enter a ground or field or surround of relations that are transformed by the intruder, even as the input is also transformed. (TT 86)

In his preface to Where Is Science Going?, Albert Einstein insists: “There is no logical way to the discovery of these elemental laws. There is only the way of intuition, which is helped by a feeling for the order lying behind the appearance.” (TT 128)

Finally, as noted in the posthumous Laws of Media:

Part of the confusion of Einsteinian four-dimensional space-time results from the figure of abstract visual space suddenly acquiring a ground of ‘relativity.’ The visual figure now relates to the speed of light as its ground…(23)

The acoustic figure, too, has this same difficult ground in simultaneity and, therefore, relativity.

But while “the speed of light as (…) ground” and the resulting “relativity” may indeed produce great “confusion”, so may they also enable in the domain of experience (as Einstein demonstrated in the physical domain) a new intelligibility.