Why are you reading my blog? I don’t mean why you are reading my blog rather than someone else’s (that much is obvious!), I mean why are you reading my blog? Or, to assign blame where it’s properly due, why did I write it?
Writing has played a crucial role in the development of civilisation, by facilitating both long-distance communication and the creation of records. Though more primitive methods of information dissemination have regained popularity over the last century (I speak of radio, television, podcasts, vlogs), written text has for millennia offered something that conversation, mime, or interpretive dance simply cannot – permanence.
So, while it’s true that I could have come and told you about this post in person, speech is a fundamentally limited mechanism for communicating at a distance because it happens in time. Whatever it is that I intend to say, I must at some point begin to say it, and at a later point finish saying it. And a moment later everything that I took such great pains to say will have disappeared from physical existence. All I can do is hope you were listening.
I’m reminded of a famous passage from Sartre’s “Nausea”, where the beauty of music is made inextricable from its demise:
For the moment, the jazz is playing; there is no melody, just notes, a myriad of tiny tremors. The notes know no rest, an inflexible order gives birth to them then destroys them, without ever leaving them the chance to recuperate and exist for themselves… I would like to hold them back, but I know that, if I succeeded in stopping one, there would only remain in my hand a corrupt and languishing sound. I must accept their death; I must even want that death: I know of few more bitter or intense impressions.
Captivating though this description is, Sartre’s connexion of musical beauty with evanescence is from my perspective specious and superficial. Evanescence is intrinsic to sound itself.
By comparison, our marks on the visible world present an air of indelibility, a comforting stasis. And this is why the majority of people record information in the visual realm, including upon the page, and not in the auditory one.
There are of course cultures whose memories and oral traditions have withstood the atrophy of industrial civilisation. In an Egyptian myth, the god Thoth visites the pharaoh bearing gifts for humanity. “Here is the calendar,” he says “to facilitate the planning of the harvest. And here is arithmetic, for the managing of commerce and for astronomical calculations.”, and so on. The pharaoh is visibly delighted with each of these new inventions. “And finally,” says Thoth, “I give you writing, as an aid to memory.”. But wise old pharaoh cuts in: “You are wrong! This will be the undoing of memory – for who will have to remember anything once it is possible to write it down?”.
(This tale echoes current debates about the externalisation of memory (and cognition in general), as consumer photography, the Web, and personal communication technologies become incresingly integrated as extensions of our individual selves. But I digress.)
Time and Waves
Returning to transformations of the visual world, and to writing in particular, it could be said that they are suspended from time: that the written word is powerful in part because it is timeless; because it can in principle be read again and again by anybody, in any order. Writing permits a “democratic” apprehension of meaning, where information is presented for the reader to consume according to their taste. Speech, conversely, is a format inextricable from time, and its power is overwhelmingly in the hands of its author. (This is true even of recorded sound.)
We may well ask whether there’s some intrinsic property of material and visual stimuli that underlies their comparative timelessness. I believe so; but before elaborating, I’d like to describe the notion of a “stimulus” from a physics-inspired perspective. In the broadest sense, a stimulus is embodied by the transfer of information from the place where it is produced to another place where it is received. According to the laws of physics, any such conveyance requires energy; and for both sound and light this energy comes in a form of a “wave”. Now, the theory of waves explains, in various guises, a great diversity of phenomena; but each one at its core involves a translocation of energy via vibration.
For sound, this vibration is “mechanical”, meaning it occurs in a material composed of atoms and molecules. For instance, the material which carries the waves of speech is air: the wave travels by making clusters of molecules vibrate and bump into their neighbours, which in turn bump into their neighbours, and so on, such that the vibration propagates through the air.
Light waves, unlike their sonic counterparts, need no tangible material in which to exist. They are composed of oscillating electric and magnetic forces which influence and sustain one another in a perpetual tarantistic reciprocation. Indeed, light can almost be said to travel through the space between particles of matter.
But whatever the specifics, waves are fundamentally ephemeral phenomena, in that they transport energy and information, yet leave little trace of their passage. There is, nevertheless, a key distinction between the waves of sound and light experienced here on Earth: namely, we possess a ready, inexhaustable source supply of light, but no such supply of sound. So while sound inevitably dies away, light is constantly replenished.
This leads us to a further related difference between visual and auditory stimuli. The former is (mostly) mediated by reflexion – whether you’re scanning the jungle, gazing at some monument, or reading a book, you’re able to do so because light has travelled from a source (e.g. the Sun), reflected off the object in question (and in so doing acquired some imprint of it), and has finally been absorbed by your eye. Light rays are mere vessels of information, whose origin is independent of and irrelevant to their cargo. Contrast this with a sound wave, which carries information pertinent almost exclusively to the origin of the sound: your friend’s voice, a tiger’s growl, rustling trees, the tumbling splashes of a far-off stream.
A World in Darkness
So my claim is that vision is our dominant sense because there exists a source of light which is both indefatigable and inert. To make this more concrete, let me indulge in some science fiction and imagine a world where light and sound have switched places: where the Sun no longer shines but hums; where we navigate not by the colour and intensity of reflected light, but by the subtle changes in pitch, volume and phase of reflected sound. The only things we’d see with our eyes would be the progenitors of light: incandescent fire, fulminant lightning, bioluciferous bacteria, perhaps bats hunting by radar instead of sonar. (Anglerfish would be everywhere.) And if we were to navigate our environment by its reflexions of this new pervasive hum, we would recognise everyday objects very differently. We’d detect their size, corners and their texture (hard, flat objects would be “bright”, and soft or recessed objects would be “dim”. How would we recognise a face?); gauging distance would be tricky, but we could get accurate measurements of speed by reading Doppler shifts. We’d design things differently too – for instance our familiar road signs, with their garish colours and simple shapes, would have to be replaced by intricate sculptures tuned to interact in particular ways with the constituent frequencies of the hum.
Our ingenuity for design notwithstanding, this would inevitably be a world awash with fresh ambiguities for the simple reason that sound waves are in many ways fragile. We already know that they require a medium through which to travel, and the signal we receive is extremely sensitive to the details of how it reached us. For instance, we know from experience that sound is deadened by humidity and waylaid by wind; that it echoes maddeningly; that it diffracts (spreads out) easily – and though this is useful for broadcasting and for learning about invisible activity around the corner, it’s inconvenient when trying to obtain precise information about the material organisation of the world around us. Sound travels a million times slower than light, so all news would be old news (unfortunate in the case of immediate danger).
In the context of the written word, further problems arise. The line of text that you’re reading now is probably less than five millimetres in height, yet you easily have enough “visual pixels” to read each character. This would not be the case in our new sonic regime: although our present anatomy allows for an auditory (wavelength) range almost a thousand times larger than our visual range, it would be incapable of resolving features smaller than one and a half centimetres.
There is plenty more to write about the physical limitations of our senses (for instance the quantum efficiency of our retinas; or how the brain integrates distributed information to form precise models of its environment), and how they might adapt to my hypothesised inversion of our communication channels. But I’ll wrap up here by re-stating my main point: that a principal reason for vision being our dominant sense of the external world is the separation of the visual realm from time – a separation founded on the abundance of an inert conduit of visual information: sunlight.