Interlocking hoops of gleaming steel etched with lines and degrees pinpoint impossibly far-off objects we will never touch. Polished surfaces reflect the surrounding here and now: sky, clouds, trees, earth. The sculpture, weighty and fixed, somehow implies—and is indeed capable of—motion. Under the spell of its beauty, one wonders whether, despite its base being bolted to the earth, the sphere may go spinning off to join the empyrean bodies it was built to measure.
This is more than a sculpture: this is an armillary sphere, and today one stands on the campus of St. John’s College in Santa Fe. Invented over two thousand years ago to map the positions of celestial objects by assigning a coordinate system to the celestial sphere, it allowed early astronomers to describe the exact location of any given point in the sky. A spherical coordinate system has two axes set up at ninety degrees to one another, and each of these axes has the shape of a ring—an armilla in Latin. The sphere has four rings: Meridian, Equatorial, Declination, and Small Carrier. All but the Meridian ring can rotate freely in order to take measurements. The Meridian ring is set due north-south and rotated to Santa Fe’s latitude so that the axis is parallel to the Earth’s.
Under the spell of its beauty, one wonders whether, despite its base being bolted to the earth, the sphere may go spinning off to join the empyrean bodies it was built to measure.
Though modeled on the illustrations and writings of sixteenth-century astronomer Tycho Brahe, this sphere was designed and manufactured by contemporary British craftsman David Harber. Harber, whose works are rooted in art, science, and ancient ideas, was delighted to undertake the commission. “This is a phenomenal project and, I hope, the start of many, many hours of star-gazing for the students of St. John’s College,” he commented by email.
Hunger for knowledge lies at the heart of the St. John’s curriculum, which explores three thousand years of human thought and discovery in chronological order. Historical scientific instruments are fundamental to the endeavor; students study science through reading original texts and conducting related experiments. This is one reason the college’s class of 2004 chose to commission and fund an armillary sphere for the Santa Fe campus, at a cost exceeding $100,000.
Harber worked with faculty as well as British scholars for over ten years, using Brahe’s drawings to create the only operational equatorial armillary sphere of such accuracy in the world. The exactitude of the measurements reported by Brahe and other astronomers using armillary spheres similar to this one later enabled Newton and Kepler to transform our understanding of the universe.
More than eight feet tall and made from marine-grade stainless steel, this armillary sphere is a decidedly modern interpretation of a historic design. As a precision instrument—albeit a very large one—the mechanisms are generally locked to protect its alignment.
In pondering our human compulsion to observe and measure, the delightfully absurd Italo Calvino story “A Sign in Space” comes to mind. The narrator, who lives during the formation of the revolving universe, draws the first-ever sign at a particular point in space so he’ll recognize it when he drifts past again, two hundred million years later. We, however, are limited to earthbound identification of such points in space, so members of the St. John’s College faculty are learning how to use the sphere and incorporate it into the curriculum. There are also plans to schedule demonstrations for outside groups. For now, anyone may visit to simply bask in the enchanting beauty of the sphere and reflect on the ageless mysteries of the cosmos.