The past is never dead. It’s not even past.
— William Falkner Requiem for a Nun
“Fathoming deep time is arguably geology’s single greatest contribution to humanity,” claimed geologist Marcia Bjornerud in her book, Timefulness: How Thinking Like a Geologist Can Help Save World (Princeton University Press, 2018). Whether on a trail along the rim of the Grand Canyon or on a yardstick kept in a schoolroom closet, human history, relative to geologic time, lays claim to just .004% of the length. When representing time since the origin of the earth from fingertip to nose on an outstretched arm, trimming a fingernail wipes out human history. On the scale of a twenty-four-hour day for representing four and one-half billion years, recorded history spans a fraction of a second just before midnight.
Although such images permeate science teaching, Bjornerud argues: “This is a wrongheaded, and even irresponsible way to understand our place in Time. . . . It suggests a degree of insignificance and disempowerment that not only is psychologically alienating but also allows us to ignore the magnitude of our effects on the planet.”
Grasping the meaning of geologic time should counter, not reinforce, feeling insignificant when confronted by the reality of time’s vastness. Time is not length—length is a metaphorical representation of time that keeps scale intact so that comparisons of relative duration may be made. Is the duration of .004% of earth’s history, on some scale, of equal importance to the other 99.996%? Or is .004% of geologic time supremely important, though miniscule? What is the value of understanding deep time—time on a geologic scale? The proper aim is to cultivate deep respect for the present moment.
The human condition is one of responsibility for the future, exercised in the present moment in the context of the accumulated past. A new day begins each midnight. Having a sense of “timefulness,” argues Bjornerud, means to think with “a clear-eyed view” of humanity’s portion of earth history and ask, “What happens after midnight?”
Early in the 1991 movie, Grand Canyon, the character Simon, played by Danny Glover, tells Mack (Kevin Kline) that standing on the rim of the canyon makes “you just realize what a joke we people are. What big heads we got thinking that what we do is gonna matter all that much. Thinking our time here means diddly to those rocks. It’s a split second we been here, the whole lot of us. And one of us? That’s a piece of time too small to give a name.”
From a different perspective, “the piece of time too small to give a name” holds inestimable value—and, in fact, does have a name: “now.” Consciousness exists in the present moment and combines with conscience to make choices. Collectively, humanity’s choices reverberate on the scale of geologic time, responsibly or irresponsibly. Informed by the perspective of geologic time, each individual’s choices matter.
At regular intervals along the Trail of Time on the Grand Canyon’s south rim, boulders rest upon plinths in the manner of classic sculpture. Ordered by age, the boulders sample each formation of rock found in the canyon. Samples span time from the ancient Elves Chasm gneiss to the canyon topping Kaibab limestone. Beside each one stands a tube, fixed in angle and direction for viewing the same rock on the wall of the canyon below the north rim. The trail offers aesthetic pleasure. It is a museum of both science and art, a coherent story that deepens the experience of the present moment (Karl Karlstrom and Laura Jones Crossey, The Grand Canyon Trail of Time Companion, Grand Canyon Conservancy, 2019).
Imagine time not as a line, but as an expanding bubble, its surface an eternal, liminal moment. By valuing a grasp of geologic time, let us accord this moment the deep respect it deserves.