One July morning during a research trip to the small New England island of Nantucket, home to pioneering astronomer Maria Mitchell, I had a most unusual experience. Midway through my daily swim in the ocean, my peripheral vision was drawn to what at first appeared to be a snorkel. But as I looked directly at the curious protrusion, I realized it was the long glistening neck of a stately bird, gliding over the nearly waveless surface a few away. By some irresistible instinct, I began swimming gently toward the bird, assuming it would fly away whenever my proximity became too uncomfortable.

But it didn’t. Instead, it allowed my approach — for it was deliberate permission that this majestic bird gave me, first assessing me with a calm but cautious eye, then choosing not to lift off or even change course as this large ungraceful mammal drew near. I came so close that I could see my own reflection in the bird’s eye, now regarding me with what I took to be — or, perhaps, projected to be — a silent benevolence.

We began swimming side by side, no more than a wingspan away from one another, and I found myself awash in awe amid the gentle waves, entranced in what could best be described as a transcendent experience — the kind that calls to mind, and called to mind in that very moment in the water, Alan Lightman’s moving encounter with the ospreys. In this small act ablaze with absolute presence, I felt I had been granted access to something enormous and eternal.

The experience was so intensely invigorating in part because it was wholly new to me, but it is far from uncommon. It belongs to the spectrum of experience which Diane Ackerman, one of the greatest science storytellers of our time, describes in Deep Play (public library) — a bewitchingly inquiry into those moods colored by “a combination of clarity, wild enthusiasm, saturation in the moment, and wonder,” which render us in a state of “waking trance.”

Ackerman — who has previously written beautifully about the secret life of the senses, our poetic communion with the cosmos, and the darkest depths of the human experience — reclaims and subverts the phrase “deep play” from Jeremy Bentham, founding father of utilitarianism, who used it pejoratively in the 18th century to connote any high-stakes activity engaging in which he deemed irrational because “the marginal utility of what you stand to win is grossly outweighed by the disutility of what you stand to lose.” But Ackerman argues that the risk involved in activities of that sort only amplifies their romance.

She considers what deep play is and why it appeals to us so profoundly:

We long for its heights, which some people often visit and others must learn to find, but everyone experiences as replenishing. Opportunities for deep play abound. In its thrall we become ideal versions of ourselves… [Its] many moods and varieties help to define who we are and all we wish to be.

Before diving into the psychological and spiritual dimensions of deep play, Ackerman examines play itself and its evolutionary function as an indelible part of sentience and a measure of the evolution of consciousness perhaps more accurate than what we refer to as intelligence. She writes:

Why play at all? Every element of the human saga requires play. We evolved through play. Our culture thrives on play. Courtship includes high theater, rituals, and ceremonies of play. Ideas are playful reverberations of the mind. Language is a playing with words until they can impersonate physical objects and abstract ideas. […] It’s so familiar to us, so deeply ingrained in the matrix of our childhood, that we take it for granted. But consider this: ants don’t play. They don’t need to. Programmed for certain behaviors, they automatically perform them from birth. Learning through repetition, honed skills, and ingenuity isn’t required in their heritage. The more an animal needs to learn in order to survive, the more it needs to play… What we call intelligence … may not be life’s pinnacle at all, but simply one mode of knowing, one we happen to master and cherish. Play is widespread among animals because it invites problem-solving, allowing a creature to test its limits and develop strategies. In a dangerous world, where dramas change daily, survival belongs to the agile not the idle. We may think of play as optional, a casual activity. But play is fundamental to evolution. Without play, humans and many other animals would perish.

It is hardly happenstance that the word “play” was central to how Einstein thought of the secret to his genius — he used the term “combinatory play” to describe how his mind works. Ackerman considers what it is that makes play so psychologically fruitful and alluring to us, plunging into its ancient cultural history:

The world of play favors exuberance, license, abandon. [In it,] selves can be revised. […] Above all, play requires freedom. One chooses to play. Play’s rules may be enforced, but play is not like life’s other dramas. It happens outside ordinary life, and it requires freedom.

Ackerman maps the etymological ecosystem of play:

Most forms of play involve competition, against oneself or others, and test one’s skills, cunning, or courage. One might even argue that all play is a contest of one sort or another. The adversary may be a mountain, a chess-playing computer, or an incarnation of evil. To play is to risk: to risk is to play. The word fight derives from the word play. Medieval tournaments were ritualized battles that followed strict rules. So are wrestling, boxing, and fencing matches. Ceremonial violence — at a sacred place, in which special clothes are worn, time limits must be obeyed, rules are followed, rituals are performed, the action is alarmingly tense, and the outcome is unknown — is elemental to play. Festive dancing may seem peaceful by comparison, and indeed in Anglo-Saxon, play was plega, which meant singing or dancing gestures, clapping, quick movements. But when we peer even farther back into its origins, we discover that play’s original meaning was quite different, something altogether more urgent and abstract. In Indo-European, plegan meant to risk, chance, expose oneself to hazard. A pledge was integral to the act of play, as was danger (cognate words are peril and plight). Play’s original purpose was to make a pledge to someone or something by risking one’s life. Who or what might that someone or something be? Possibilities abound, including a relative, a tribal leader, a god, or a moral trait such as honor or courage. At its heart, plegan reverberated with ethical or religious values. It also contained the idea of being tightly fastened or engaged. Soon plegan became associated with performing a sacred act or administering justice, and it often appeared in ceremonies.

But while simple play may have its timeless appeal, Ackerman focuses on a deeper and more transcendent kind of play — something more rapturous and closer to ecstasy, something that helps us contact our hidden wholeness and is perhaps even required for us to feel whole. She explores the essential point of difference:

Deep play is the ecstatic form of play. In its thrall, all the play elements are visible, but they’re taken to intense and transcendent heights. Thus, deep play should really be classified by mood, not activity. It testifies to how something happens, not what happens. Games don’t guarantee deep play, but some activities are prone to it: art, religion, risk-taking, and some sports — especially those that take place in relatively remote, silent, and floaty environments, such as scuba diving, parachuting, hang gliding, mountain climbing. Deep play always involves the sacred and holy, sometimes hidden in the most unlikely or humble places — amid towering shelves of rock in Nepal; crouched over print in a dimly lit room; slipping on AstroTurf; wearing a coconut-shell mask. We spend our lives in pursuit of moments that will allow these altered states to happen.

Ackerman narrows in on the seemingly subtle yet monumental difference between the two states most closely associated with deep play, rapture and ecstasy:

Rapture and ecstasy are not themselves deep play, but they’re central components of it. Rapture means, literally, being “seized by force,” as if one were a prey animal who is carried away. Caught in the talons of a transcendent rapture, one is gripped, elevated, and trapped at a fearsome height. To the ancient Greeks, this feeling often foretold malevolence and danger — other words that drink from the same rapturous source are rapacious, rabid, ravenous, ravage, rape, usurp, surreptitious. Birds of prey that plunge from the skies to gore their victims are known as raptors. Seized by a jagged and violent force, the enraptured are carried aloft to their ultimate doom. Ecstasy also means to be gripped by passion, but from a slightly different perspective: rapture is vertical, ecstasy horizontal. Rapture is high-flying, ecstasy occurs on the ground. For some reason, the ancient Greeks were obsessed with the symbol of standing, and relied on that one image for countless ideas, feelings, and objects. As a result, a great many of our words today simply reflect where or how things stand: stanchion, status, stare, staunch, steadfast, statute, and constant. But there are also hundreds of unexpected ones, such as stank (standing water), stallion (standing in a stall), star (standing in the sky), restaurant (standing place for the wanderer), prostate (standing in front of the bladder), and so on. To the Greeks, ecstasy meant to stand outside oneself. How is that possible? Through existential engineering. “Give me a place to stand,” Archimedes proclaimed in the third century B.C., “and I will move the earth.” Levered by ecstasy, one springs out of one’s mind. Thrown free of one’s normal self, a person stands in another place, on the limits of body, society, and reason, watching the known world dwindle in the distance (a spot standing far away). The euphoria of flying in dreams, or the longing to fly through the ocean with dolphins, fills us with rapture.

It is hardly any surprise that elements of deep play can be found in most of our major efforts to make sense of the human experience, from Ancient Greek philosophy to Freud’s notion of “oceanic feeling” to Mihalyi Csikszentmihalyi’s concept of “flow.” Turning once again to the lens of language — for, lest we forget, language is our mightiest vehicle for the self — Ackerman contemplates deep play’s singular quality of being:

Deep play is a fascinating hallmark of being human; it reveals our need to seek a special brand of transcendence, with a passion that makes thrill-seeking explicable, creativity possible, and religion inevitable. Perhaps religion seems an unlikely example of playing, but if you look at religious rites and festivals, you’ll see all the play elements, and also how deep that play can become. Religious rituals usually include dance, worship, music, and decoration. They swallow time. They are ecstatic, absorbing, rejuvenating. The word “prayer” derives from the Latin precarius, and contains the idea of uncertainty and risk. Will the entreaty be answered? Life or death may depend on the outcome.

Reading over a journal entry from her own youth, in which her long-ago self describes the transcendence of travel in a way that calls to mind Albert Camus’s longer-ago meditation on why we voyage, Ackerman extrapolates a common root of deep play across its many guises:

One enters into an alternate reality with its own rules, values, and expectations. One sheds much of one’s culture, with its countless technical and moral demands, as one draws on a wholly new and sense-ravishing way of life… One chooses to divest oneself of preconceptions, hand-me-down ideas, and shopworn opinions, chooses to wipe the mental slate clean, chooses to be naive and wholly open to the world, as one once was as a child. If cynicism is inevitable as one ages, so is the yearning for innocence. To children heaven is being an adult, and to adults heaven is being children again. […] As the world reduces to a small brilliant space, where every thought and move is vital to one’s salvation, one’s scattered energy suddenly has a center. Only then do all of our senses spring alert, and every sensation matters. At the same time, the rest of the world recedes. One is temporarily unshackled from life’s chains — the family ones, the work ones, the ones we wear as self-imposed weights.

But perhaps the single most perceptible characteristic of deep play is the way in which it alters our already warped experience of time by summoning us to that place where impulsivity and control intersect to grant us absolute access to presence. In a passage that calls to mind Kafka’s assertion that “reality is never and nowhere more accessible than in the immediate moment of one’s own life,” Ackerman considers the reality-concentrating power of deep play through the prism of time:

In deep play, one’s sense of time no longer originates within oneself. […] We want to muscle into life and feel its real power and sweep. We want to drink from the source. In rare moments of deep play, we can lay aside our sense of self, shed time’s continuum, ignore pain, and sit quietly in the absolute present, watching the world’s ordinary miracles… When it happens we experience a sense of revelation and gratitude. Nothing need be thought or said. There is a way of beholding that is a form of prayer. […] When one enters the realm of deep play, the sacred playground where only the present moment matters, one’s history and future vanish. One doesn’t remember one’s past, needs, expectations, worries, real or imaginary sins. The deep-play world is fresh, wholly absorbing, and full of its own unique wisdom and demands. Being able to temporarily step outside of normal life—while keeping one’s senses alert — is indeed like being reborn. To erase all memories and yearnings — to be vigorously alive without self-awareness — can provide a brief return to innocence.

In the remainder of the wholly enchanting Deep Play, Ackerman goes on to explore the types of experiences that grant us entry into this sacred world and the moods, mental states, and orientations of spirit that make us better able to conjure up the temperament of receptivity needed to experience deep play. Complement with Ackerman on the science of smell, what Earth’s nocturnal portrait from space reveals about who we are, and her beautiful poems for the planets.