Vision, Time, Light and Space

The evolution of the eye, ancient astronomy, and Roden Crater

What we see, we see / and seeing is changing / the light that shrivels a mountain / and leaves a man alive / Heartbeat of the pulsar / heart sweating through my body / The radio impulse / pouring in from Taurus / I am bombarded yet I stand

— from “Planetarium,” by Adrienne Rich

As February passes into March, the cold nights of winter begin to warm a little and the balance of darkness moves toward light. My eyes have grown tired of the brown monochrome that is the daytime landscape here and begin to thirst for green. But if there’s any consolation to those frigid nights, it’s the clarity, depth, and stillness of the sky, lately made even stiller by the decreased air traffic of these pandemic times.

On nights like this, Tasha and I like to soak in our wood-fired hot tub, which we also use to heat our greenhouse. In between soaks, we cool off on Adirondack chairs at the edge of a pond. Here at the top of our property on the side of a mountain, we can look up at the bowl of the sky, hemmed in on all sides by trees. If the wind is still, we can see celestial light reflected on the pond’s surface.

Looking out over the southern sky, faintly hued planets travel on their subtle paths over the course of hours. With the moon absent, constellations trace out the darkness in glittering points of light, set against fainter layers of stars smoldering away in the inky background. And if it’s very dark and clear, the Milky Way is faintly visible—a luminous band arcing away into vague categories of thought in which familiar notions like time, space and distance fall apart.

Amidst this dazzlement, it has occurred to me: Light is falling on my eyes from a time before there were eyes to see it.

The Birth of Vision

Life has existed on Earth for close to 3.7 billion years. Within this staggering timespan, itself dwarfed only by the age of the Universe, organs that we would recognize as eyes have only existed for about 540 million years. But eyes did not just suddenly appear then and their evolution was not inevitable.

The evolutionary process that culminated with the first eyes probably began much earlier, when cyanobacteria evolved the first chloroplasts—cellular components that enable photosynthesis. Chloroplasts allow the cell to make use of the visible spectrum of sunlight, converting solar energy into chemical energy and producing oxygen as a byproduct.

While the oxygen emitted by chloroplasts would eventually result in the greening of the planet, chloroplasts also produced beta carotene during photosynthesis, which led to the production of a pigment called retinal. When retinal combined with a class of proteins called opsins, photosensitive cells were born.

This combination of chemicals enabled primitive, single-celled organisms such as Chlamydomonas, a type of alga that still exists today, to sense light through an ‘eyespot’ and react to it. This mechanism of action, known as phototaxis, allows a single-celled organism lacking a nervous system to move toward a light source.

Groupings of photosensitive cells over time formed what are known as eyespots in multicellular organisms like modern leeches. These light-sensitive patches could only differentiate between light and dark, but driven by the Pax gene family, they may have developed quickly—in evolutionary terms anyway—in less than half a million years from eyespots to fully formed camera-style eyes.

The next step up from eyespots was to form a small depression, a pit or an ‘eyecup’ containing these photosensitive cells, which allowed for a sense of direction and movement in response to light stimuli entering the pit. Limpets, a kind of snail, retain this primitive visual system.

Continuing its development, a narrowing in the opening around the pit of this primitive eye emerged, creating an aperture or chamber allowing the ‘retina,’ to sense images. This visual mechanism is similar to a pinhole camera and can still be found in the nautilus.

The final step to achieving a camera-style eye with fully formed imaging capabilities was the evolution of the lens, along with a cornea and muscles to focus the moving parts of the eye. Box jellyfish, though they lack a brain, employ this type of visual system, comprising a lens, retina, iris, and cornea.

Trilobites—small arthropods resembling marine lice—were the first animals to build on this fully functional eye to evolve a compound eye with multiple lenses. These animals’ compound eyes consisted of a retina, lens, pupil and optic nerve, even if that eye didn’t yet have what could be called a brain to connect to.

Yet this eye, unique in the the early Cambrian period, represented a huge evolutionary leap. With the ability to see clearly, and hence detect motion and direct their own locomotion, trilobites became the first truly active predators. Their presence drove the enormous burst of diversification and biological innovation that characterized the ‘Cambrian Explosion.’

Other evolutionary innovations followed between the Cambrian and the present, but the first vertebrates—hagfish and lampreys—also emerged during this period with camera-style eyes. The lamprey eye has a retina that resembles that of fish and mammals, neither of which had evolved yet at that point in time.

The following period, the Devonian, which began about 415 million years ago, is known as the ‘age of fishes,’ though terrestrial animals also began to evolve as aquatic life came ashore during this time. This is significant because the new environment of terrestrial life drove many visual adaptations. One of the first of these was binocular vision, which began with early amphibians.

The Carboniferous period of about 362 million years ago saw further development of life on land. Meanwhile, synapsids, a class of terrestrial vertebrates, were evolving in the direction of mammals, which would first appear toward the end of the Triassic Period, between 210 and 200 million years ago.

As placental mammals began to appear about 160 million years ago, the next major innovation was color vision. Our primate ancestors, who first appeared about 77 million years ago, had dichromatic, and eventually trichromatic, vision. The most important consequence of color vision was the neurologic development necessary to manage the sensory input from such a highly evolved organ as the primate eye.

Some evolutionary biologists believe that advances in visual perception and resolution drove major development in the brains of our primate ancestors. The consequences of this development of a sophisticated brain were truly earth-shattering: The first hominids would part ways with our last common primate ancestor between six and seven million years ago.

Eyes to the Skies

Sometime between now and five million years ago when self-consciousness began to arise in our distant ancestors, hominids started to see connections between the lights in the night sky and life here on Earth. Of the natural sciences, astronomy is the oldest. Evidence for this claim, among others, exists in a 32,000-year-old mammoth tusk showing a star chart of the constellation Orion. At this point in history, human cultures were still many thousands of years away from taking up the practices of settled agriculture that would drive the development of civilization and hence require the technical expertise of a calendar system for planting and harvesting.

Nonetheless, the oldest known astronomically-based calendar was recently discovered in Scotland. This Mesolithic monument, the Warren Field calendar, is 10,000 years old and predates agriculture in the British Isles by many thousands of years. It consists of a series of 12 pits dug along a gently sloping landscape that track the phases of the Moon, aligning at sunrise on the winter solstice and linking the solar year to lunar cycles. This ‘time reckoner’ enabled a rudimentary type of time-keeping. Amazingly, the calendar at this site appears to have been maintained over a period of 6,000 years in accordance with shifts in these lunar cycles until about 4,000 years ago, when it was abandoned.

Landscape archaeologist Vince Gaffney, in a BBC News piece on the discovery, said: "The evidence suggests that hunter-gatherer societies in Scotland had both the need and sophistication to track time across the years, to correct for seasonal drift of the lunar year and that this occurred nearly 5,000 years before the first formal calendars known in the Near East. In doing so, this illustrates one important step towards the formal construction of time and therefore history itself."

One can only wonder at the purpose for such an undertaking as building a land calendar, especially for a group of hunter-gatherers who were not ‘attached’ to the land in the way that later agricultural societies were. There is evidence to suggest however that large seasonal congregations may have occurred at Warren Field and elsewhere, and that their timing was crucial in order for seasonal natural resources to be available to support such large groups.

Whatever the calendar’s purpose it marks, as Gaffney notes, the emergence of a sense of history. The recognition of the cyclical movement of time in accordance with celestial rhythms is the foundation that undergirds so many aspects of human experience. Observations of the cosmos are bound up with religious, mythological, astrological, and calendrical significance for peoples throughout history, so it’s not surprising that many early artifacts and archaeological sites, like the Lascaux cave paintings and Stonehenge, allude or relate to celestial events.

Many of the world’s first great civilizations, established thousands of years later as a consequence of the ‘settled life’ of agrarianism, were built around the contributions of a technically sophisticated astronomy. While the next-oldest known calendar was developed in Mesopotamia by the Sumerians around 3,000 BCE, it’s no coincidence that its practice coincides with the adoption of agriculture there. This took place amidst and in spite of arid conditions that made the region especially reliant on regular irrigation and hence less than favorable to farming.

The ancient Egyptians likewise based their agricultural activities around the regular flooding of the Nile, which was predicted by the annual re-emergence of the star Sirius in the dawn hours of mid-summer. Chinese astronomers developed their science too for the purposes of timekeeping, and Mayan astronomers in pre-Columbian North America independently developed a system of astronomy that was more accurate in calculating the solar year than the Gregorian Calendar, on which our modern adaptation of the 365.25-day-year is based.

What so many cultures throughout human history had—reinforced by astronomical observations—was a vital, cyclical relationship with the natural world which they understood to sustain them. The development of modern Western Civilization over the past few centuries has however resulted in a rift in human consciousness in relation to the natural world and our place in it.

The early 20th century writer D. H. Lawrence devoted much of his later life to traveling around the world in search of intact and still vital ‘primal’ cultures. Traveling to places like New Mexico, Sri Lanka, Australia, and Sicily, Lawrence sought to find mythologies and ways of seeing and being that had not succumbed to the modern malaise, the cultural deadness, brought on by the ‘advances’ of the Industrial Revolution and scientific progress.

Lawrence also looked to ancient cultures, such as that of the Etruscans and Chaldeans, for a glimpse of this lost and vital world. In Apocalypse, one of his last works, he relates:

“I would like to know the stars again as the Chaldeans knew them, two thousand years before Christ. I would like to be able to put my ego into the sun, and my personality into the moon, and my character into the planets, and live the life of the heavens, as the early Chaldeans did… Because our sun and our moon are only thought-forms to us, balls of gas, dead globes of extinct volcanoes, things we know but never feel by experience.”

But Lawrence’s yearning for the restoration of a lost sense of wholeness and harmony with the life of the cosmos and the natural world, a world of cyclical time, is expressed by others from the same period, most notably perhaps, by W. B. Yeats.

In one of the most powerful and eloquent essays I’ve read on the subject, “A Storm Blown from Paradise,” Paul Kingsnorth elaborates on how our culture’s internalization of linear time has led to the seemingly intractable crises we now face, in both the inner and the physical worlds we inhabit:

“We have been brought up to believe that history marches in one direction, and that this requires us to be either optimistic or pessimistic about the direction of the march. We can choose to believe that everything is getting better or that everything is getting worse, but both beliefs take us endlessly forward. Whether the past was misery and the future is utopia, or the past was the utopia and the future offers only apocalypse, the progressive vision requires us to believe that the line, not the circle, is the framing image of our journey through life.”

Throughout the essay, Kingsnorth employs insights from Yeats, Walter Benjamin, David Abram, Jay Griffiths, Black Elk and others to help make his case. But as he himself so beautifully puts it,

“If the world, and time itself, is cyclical, then everything that will happen has already happened. Change is inevitable, death is part of that change, the future and the past hold hands. In a cyclical world, as in a calendar year, what has been will be again, and vice versa. The leaves of the tree die every autumn and grow every spring. Nothing changes and everything changes and each human life, like each leaf on a tree, is part of the endless, effortless, turning of the wheel.”

Yeats’ concept of the gyre—the helically spiralling and interlinked forces of historical development and breakdown—informs the logic of Kingsnorth’s essay. As the 2,000 year cycle that began with Christ’s birth concludes and breaks down—as things fall apart—a new cycle begins, and it is here that the essay concludes.

Kingsnorth urges us to embrace “A return to cyclical thinking—to notions of fate and repeating time, to an understanding of the small place of a single life in the great unfolding… It might allow us again to notice the other life forms that surround us, to see ourselves in the cycle of life, and to sit amongst the ruins of our fantasies not with eyes full of despair, but of possibility.”

Roden Crater


I first read about Roden Crater years ago in an essay by the recently deceased Barry Lopez, entitled “Flight.” In the essay, Lopez tells of a massive ongoing project by artist and pilot James Turrell—a sort of natural observatory in which “one could perceive the ‘celestial vault’ above the Earth, and that a view from within the crater could reveal that architecture by so disposing the viewer.“ Intrigued, I decided to find out more about the project and about Turrell.

Roden Crater—at once a giant eye, an observatory, and a work of art—sits on the site of an extinct volcanic cinder cone in the Painted Desert of Arizona, outside of Flagstaff. Since Turrell acquired the three-mile-wide crater in 1979, he has worked to reshape its natural landscape by using earth moving equipment, as funding permitted, to craft what has become his magnum opus.

In Turrell’s own words on the project, he states simply, “I had a thought to bring the cosmos closer, down to the space we occupy.” His earlier works, many of them smaller installations or exhibits termed ‘skyspaces,’ are based on theories of light and perception that also guide his work on Roden Crater.

Dug into Roden Crater is a network of chambers, tunnels and apertures that will, according to the project’s website, when completed “form a vast naked eye observatory for celestial objects and events ranging from the obscure and infrequent to the more familiar summer and winter solstice.“ According to astronomer Richard Walden, “Celestial events will be apparent at the crater that you will only be able to see at a few other spots on the Earth.”

Roden Crater is not yet open to the public, though some visitors have experienced the space and can attest to Turrell’s success at revealing the ‘form’ of the heavens. The long-running project’s completion date though has been something of a moving target. Originally scheduled to open in 2011, the project made headlines in 2019 when Kanye West donated $10 million in funding. A campaign to raise another $200 million to see the project through to completion by 2024 has since been announced.

In considering the project of Roden Crater and the massive costs and scales involved, one might be forgiven for suspecting a streak of hubris or grandiosity on the part of its creator. Much about Roden Crater seems distinctly pharaonic but Turrell, a Quaker, comes off as serious but humble in interviews about his work. He sees himself as a “mound builder,” making “things that take you up into the sky.”

Though pyramids come first to mind, language from Turrell’s website grounds his work in human astronomical-architectural endeavors throughout history: “Above-ground observatories for specific celestial events include Maeshowe in Scotland (which predates the pyramids), Newgrange in Ireland, and Abu Simbel in Egypt. Remnants of ancient sites that resemble ‘handmade volcanoes,’ large mounds with a depression at the summit, are also scattered around the world. These include Herodium near Jerusalem and Old Sarum in England.”

Through Roden Crater, Turrell has articulated his ultimate aim as an artist: “In this stage set of geologic time, I wanted to make spaces that engage celestial events in light so that the spaces perform a ‘music of the spheres’ in light.” Seen through this lens, Roden Crater represents a culmination of humanity’s visual and perceptual experience of the cosmos, literally grounded in the Earth from which we have evolved and which is our one true home.


I look forward to the possibility of one day visiting Roden Crater—to witness how the ingenuity and creative spirit of one man can expand humanity’s understanding of our place in the universe. Perhaps Turrell’s master work will enable us to know the heavens as the Chaldeans once did and as D. H. Lawrence longed to do.

And perhaps the experience of Roden Crater will instill in its visitors a renewed reverence for the cosmos and the enormous cyclical timescales that we are but a small part of, including those that encompass the evolution of the eye—from a couple of chemicals in a single cell to the extraordinary organ of sight capable of taking in the grandeur and wonder of the heavens. I hope so.

Get in touch

Leave a comment