“It’s part of the nature of man,” Ray Bradbury told Carl Sagan and Arthur C. Clarke as they peered into the future of space exploration, “to start with romance and build to a reality.” “What would happen,” Marshall McLuhan wondered in his seminal 1964 treatise Understanding Media: The Extensions of Man, “if art were suddenly seen for what it is, namely, exact information of how to rearrange one’s psyche in order to anticipate the next blow from our own extended faculties?” More than a quarter century later, Leonard Shlain picked up the inquiry with added dimension in Art & Physics: Parallel Visions in Space, Time, and Light (public library) — an exploration of how “the inscrutability of modern art and the impenetrability of the new physics” intersect in a shared system of thinking about how the world works. In the preface, Shlain — neither an artist nor a physicist himself — considers how his training as a surgeon lends him a unique perspective on the two fields and their cross-pollination:

A surgeon is both an artist and a scientist… Surgeons rely heavily on their intuitive visual-spatial right-hemispheric mode. At the same time, our training is obviously scientific. Left-brained logic, reason, and abstract thinking are the stepping-stones leading to the vast scientific literature’s arcane tenets. The need in my profession to shuttle back and forth constantly between these two complementary functions of the human psyche has served me well for this project.

Shlain lays out the basic premise of the parallel between the two fields:

Art and physics are a strange coupling. Of the many human disciplines, could there be two that seem more divergent? The artist employs image and metaphor; the physicist uses number and equation. Art encompasses an imaginative realm of aesthetic qualities; physics exists in a world of crisply circumscribed mathematical relationships between quantifiable properties. Traditionally, art has created illusions meant to elicit emotion; physics has been an exact science that made sense… Yet, despite what appear to be irreconcilable differences, there is one fundamental feature that solidly connects these disciplines. Revolutionary art and visionary physics are both investigations into the nature of reality. Roy Lichtenstein, the pop artist of the 1960s, declared, “Organized perception is what art is all about.” Sir Isaac Newton might have said as much for physics; he, too, was concerned with organizing perceptions. While their methods differ radically, artists and physicists share the desire to investigate the ways the interlocking pieces of reality fit together. This is the common ground upon which they meet.

Turning to the question of originality, Shlain argues that both art and physics are propelled by revolutionary insight — that transcendent clarity of vision that Rilke called a “conflagration of clear sight” — which reframes our understanding of the world:

Although the development of physics has always depended upon the incremental contributions of many original and dedicated workers, on a few occasions in history, one physicist has had an insight of such import that it led to a revision in his whole society’s concept of reality. . . . Emile Zola’s definition of art: “Nature as seen through a temperament,” invokes physics, which is likewise involved with nature. The Greek word, physis, means “nature.” … The physicist, like any scientist, sets out to break “nature” down into its component parts to analyze the relationship of those parts. This process is principally one of reduction. The artist, on the other hand, often juxtaposes different features of reality and synthesizes them, so that upon completion, the whole work is greater than the sum of its parts. There is considerable crossover in the technique used by both. The novelist Vladimir Nabokov wrote, “There is no science without fancy and no art without facts.” […] In addition to illuminating, imitating, and interpreting reality … artists create a language of symbols for things for which there are yet to be words.

This capacity for abstraction and symbolic representation, Shlain argues, is hard-wired into the evolution of our cognitive development:

Observe any infant as it masters its environment. Long before speech occurs, a baby develops an association between the image of a bottle and a feeling of satisfaction. Gradually, the baby accumulates a variety of images of bottles. This is an astounding feat considering that a bottle viewed from different angles changes shape dramatically: from a cylinder to an ellipse to a circle. Synthesizing these images, the child’s emerging conceptual faculties invent an abstract image that encompasses the idea of an entire group of objects she or he will henceforth recognize as bottles. This step in abstraction allows the infant to understand the idea of “bottleness.”

This rudimentary faculty remains central to how we make sense of the world as adults and how we grasp its immaterial subtleties:

Concepts such as “justice,” “freedom” or “economics” can be turned over in the mind without ever resorting to mental pictures. While there is never final resolution between word and image, we are a species dependent on the abstractions of language and in the main, the word eventually supplants the image. When we reflect, ruminate, reminisce, muse and imagine, generally we revert to the visual mode. But in order to perform the brain’s highest function, abstract thinking, we abandon the use of images and are able to carry on without resorting to them. It is with great precision that we call this type of thinking, “abstract.” This is the majesty and the tyranny of language. To affix a name to something is the beginning of control over it. . . . Words, more than strength or speed, became the weapons that humans have used to subdue nature.

Children’s use of metaphor, we now know, sheds light on the evolution of human imagination — something Shlain argues is central to our ability to navigate the world. Adding to history’s most elegant definitions of art, he argues for the cultural role of the artist in fostering this crucial domain of understanding:

Because the erosion of images by words occurs at such an early age, we forget that in order to learn something radically new, we need first to imagine it. “Imagine” literally means to “make an image.” … [If] this function of imagination, so crucial to the development of an infant, is also present in the civilization at large, who then creates the new images that precede abstract ideas and descriptive language? It is the artist. […] Art [lives] not only as an aesthetic that can be pleasing to the eye but, as a Distant Early Warning system of the collective thinking of a society. Visionary art alerts the other members that a conceptual shift is about to occur in the thought system used to perceive the world.

He cites art critic Robert Hughes’s assertion that “the truly significant work of art is the one that prepares the future” and adds:

Repeatedly throughout history, the artist introduces symbols and icons that in retrospect prove to have been an avant-garde for the thought patterns of a scientific age not yet born. […] Revolutionary art in all times has served this function of preparing the future.

Shlain returns to the common ground between art and physics, both of which serve as tools for mapping the unknown:

Both art and physics are unique forms of language. Each has a specialized lexicon of symbols that is used in a distinctive syntax. Their very different and specific contexts obscure their connection to everyday language as well as to each other. Nevertheless, it is noteworthy just how often the terms of one can be applied to the concepts of the other… While physicists demonstrate that A equals B or that X is the same as Y, artists often choose signs, symbols and allegories to equate a painterly image with a feature of experience. Both of these techniques reveal previously hidden relationships. […] Revolutionary art and visionary physics attempt to speak about matters that do not yet have words. That is why their languages are so poorly understood by people outside their fields. Because they both speak of what is certainly to come, however, it is incumbent upon us to learn to understand them.

Turning to the famous Tower of Babel myth — a Biblical story about humanity’s collaborative effort to build a tower that would reach the heavens, paralyzed by an indignant god’s spell that transformed people’s previously common language into garbled speech that made them unable to communicate and collaborate — Shlain draws a parallel to the artificial garbling of the shared language of art and physics:

History has been the record of our agonizingly slow resumption of work on this mythic public monument to knowledge. Gradually the parochial suspicions that had been abetted by large numbers of local dialects have given way to the more universal outlook of modern humankind. Currently, this work in progress is the creation of a global commonwealth. The worldwide community of artists and scientists is and has been in the forefront of this coalescence, offering perceptions of reality that erase linguistic and national boundaries. Reconciliation of the apparent differences between these two unique human languages, art and physics, is the next important step in developing our unifying Tower.

Both disciplines, he argues, first require us to ask how we know the world. Tracing the history of the answer from Plato to Descartes to Kant, Shlain points to philosophers’ distinction between “the inner eye of imagination and the external world of things” as a toxic and artificial divide that drove art and physics apart:

The faculty we use to grasp the nature of the “out there” is our imagination. Somewhere within the matrix of our brain we construct a separate reality created by a disembodied, thinking consciousness. This inner reality is unconnected to external space and exists outside the stream of linear time. When reminiscing about a day at the beach, we knit together elements of that day that no longer “actually” exist. We can run the events forward and backward with ease, and amend with alternate possibilities what we believe happened… Consciousness, resembling nothing so much as long columns of ants at work, must laboriously transfer the outside world piece by piece through the tunnels of the senses, then reconstruct it indoors. This inner spectral vision amounts to a mental “opinion” unique to each individual of how the world works… When an entire civilization reaches a consensus about how the world works, the belief system is elevated to the supreme status of a “paradigm,” whose premises appear to be so obviously certain no one has to prove them anymore.

Shlain points to the beginning of the 20th century, when Einstein’s theory of photons challenged two centuries of considering light a wave, as a turning point for the integration between art and physics. Suddenly, by acknowledging the contradictory duality of light as both a particle and a wave, science had to confront its basic tenet of objectivity and fixed laws. As Shlain puts it, “at the turn of the century, what was to be a surprising feature of quantum reality amounted to a Zen koan.”

In 1926, Niels Bohr formalized this notion in his theory of complementarity, which stated that light was not either a wave or a particle, but was both a wave and a particle. Shlain writes:

As it turned out, light would reveal only one aspect of its nature at a time, resembling an odd carnival peep show. Whenever a scientist set up an experiment to measure the wavelike aspect of light, the subjective act of deciding which measuring device to use in some mysterious way affected the outcome, and light responded by acting as a wave. The same phenomenon occurred whenever a scientist set out to measure the particlelike aspect of light. Thus “subjectivity,” the anathema of all science (and the creative wellspring of all art) had to be admitted into the carefully defended citadel of classical physics. Werner Heisenberg, Bohr’s close associate, said in support of this bizarre notion, “The common division of the world into subject and object, inner world and outer world, body and soul is no longer adequate…. Natural science does not simply describe and explain nature; it is part of the interplay between nature and ourselves.” According to the new physics, observer and observed are somehow connected, and the inner domain of subjective thought turns out to be intimately conjoined to the external sphere of objective facts.

From this revolutionary duality of light Shlain extracts a broader metaphor for his central thesis:

[Through] the complementarity of art and physics … these two fields intimately entwine to form a lattice upon which we all can climb a little higher in order to construct our view of reality. Understanding this connection should enhance our appreciation for the vitality of art and deepen our sense of awe before the ideas of modern physics. Art and physics, like wave and particle, are an integrated duality: They are simply two different but complementary facets of a single description of the world. Integrating art and physics will kindle a more synthesized awareness which begins in wonder and ends with wisdom.

In the remainder of Art & Physics, a mind-expanding read in its totality, Shlain goes on to trace the evolution of human thinking and knowledge from Ancient Greece to the Renaissance to the 20th century, exploring various aspects of the parallels between the two disciplines, from Einstein and Picasso’s “common vision” to the interplay between illusion and reality to how music integrates the reason of science with the emotional expressiveness of art. Complement it with Dorion Sagan (son of Carl) on how science and philosophy enrich each other.