A Monument of Time: The Hoover Dam's 26,000-Year Star Chart
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The completion of a significant monument like the Hoover Dam challenges our conventional perception of time, blending elements of science and art.
As noted by Oskar J. W. Hansen, the historic mission of sculpture is to create an enduring realization of humanity, helping to preserve our aspirations against the relentless passage of time.
> “The historic mission of sculpture is…to evoke a pungent realization of man and to make this realization nearly imperishable against the oblivion imposed by time. It may also shape a symbolism in human form in order to convey the very best within the reach of the aspirations and endowment of the race.” > — Oskar J. W. Hansen, Sculptures at Hoover Dam, US Bureau of Reclamation, 1978
Our understanding of time is often limited, shaped by our brief lifespans and the units we utilize to measure it. The average human life is under a century, leading us to focus on seconds, minutes, hours, and years to mark milestones.
However, when discussing the ages of natural landmarks, like the Earth’s estimated 4.5 billion years, these measurements become almost ungraspable. Yet, human-made structures can also transcend our temporal understanding:
- The Great Pyramid of Giza is around 4,500 years old.
- Göbekli Tepe in Turkey might date back 11,000 years.
- The Roman Colosseum is over 2,000 years old.
These monumental works were crafted from materials intended to withstand the passage of time, representing humanity’s desire to create lasting legacies. Oskar J. W. Hansen was reminded of this when chosen to design a sculpture for the Hoover Dam, a project that was anything but ordinary.
The US Bureau of Reclamation emphasizes that:
> “Hoover Dam was the first man-made structure to exceed the masonry mass of the Great Pyramid of Giza. The dam contains enough concrete to pave a strip 16 feet wide and 8 inches thick from San Francisco to New York City. More than 5 million barrels of Portland cement and 4.5 million cubic yards of aggregate went into the dam.”
This structure stands among the great works of history, built to endure for millennia. Hansen's vision needed to reflect a representation of time that surpassed human years.
By utilizing the concept of a Platonic Year—now recognized as the Precession of the Equinoxes—Hansen marked the precise date of the Hoover Dam's dedication on an artistic star map that spans nearly 26,000 years.
Understanding this celestial phenomenon is essential to grasp the significance of the artistic representation.
The Precession of the Equinoxes
So, how does this cycle function?
First, envision the Earth’s rotation, which creates day and night. However, the planet also tilts as it spins. Imagine a spinning top; if you place an arrow at the top of the Earth, it would trace a circular path in the sky.
The astronomy department at the University of Lincoln, Nebraska, explains that the Earth is tilted at an angle of 23.5 degrees due to its non-spherical shape and the gravitational influences of the Sun and Moon. This tilt causes the Earth’s axis to wobble, tracing out a conical shape over approximately 26,000 years.
While it may appear that the stars are shifting, it is actually the Earth completing its rotation. Hipparchus, a Greek astronomer, discovered this phenomenon in 129 BC, noticing differences in star positions compared to earlier Babylonian records.
The angle of the pole indicates where Thuban was around 5,000 years ago, aligning with the Great Pyramid, while the current pole star is Polaris. As time progresses, future generations will see different pole stars, and there may even be periods lacking a clear north star.
The question arises: how does one commemorate a date using such a complex celestial chart near a functional dam? The answer lies in the determination of the artist.
The Monument Within A Monument
Hansen didn’t merely create a star chart; he fashioned a monument within a monument. The black stone where the bronze figures and flagpole are located is diorite, an igneous rock sourced from California, favored by ancient Egyptian artists.
To ensure the integrity of the stone, construction crews placed it on ice blocks, guiding it into position as the ice melted. The black base of the monument is made of terrazzo. The star chart is visible near the base, which we will explore shortly.
At the center of the diorite block stands a flagpole, 142 feet high, anchored in a specially crafted socket within the rock. This flagpole is significant in marking a specific point.
Next, we have the “Winged Figures of the Republic,” statues standing 30 feet tall, crafted from 4 tons of statuary bronze. Hansen aimed for their facial features to resemble those of eagles.
While they appear contemplative, their hands and wings are poised, ready to take flight. Hansen states, “The Winged Figures of the Republic give evidence to the thought which preceded the reality of Hoover Dam and to that eternal vigilance which is the price of liberty.”
The star chart is the central theme of this section, although its brilliance can often be overshadowed by the grandeur of the surrounding elements.
The Star Chart
> “Time, the intangible governor of all our acts, is measured to us by the external relations of our Earth to other worlds in space. Therefore, I thought it fitting to have the base of the monument rise from a finely wrought, marble terrazzo star map of the northern regions of the sky.” > — Oskar J. W. Hansen, Sculptures at Hoover Dam, US Bureau of Reclamation, 1978
According to Michael Hiltzik in Colossus: Hoover Dam and the Making of the American Century, Hansen dedicated three years to the creation of this star chart, employing “an intricate framework of compasses, calipers, and protractors, shunning conversation with inquisitive onlookers.”
Hansen utilized the flagpole to indicate the sun's position on the dedication day, September 30, 1935, ensuring that it pointed directly at the center of the sun.
The black circle with the white wedge signifies the Earth’s rotation on the day of the dam's dedication. This 26,000-year chart allows for precise calculations of the year, day, minute, and second of the dedication.
Additionally, significant moments in human history are marked on the chart, including the position of the Great Pyramid when Thuban served as the pole star and the birth of Christ, located between Thuban and Polaris. As one continues to explore the base, Vega, our future pole star, can also be found.
The chart illustrates various stars' magnitudes, which the human eye can observe at a distance of 10 parsecs from Earth—equivalent to roughly 19 trillion miles. However, the actual distance is closer to 50 parsecs, as Hansen enhanced visibility for better comprehension.
Hansen collaborated with experts, using calculations from the Naval Observatory, the Smithsonian Astrophysical Laboratory, and others to accurately position the celestial bodies on the terrazzo to the smallest detail.
Thus, Hansen’s monument not only commemorates the dam's dedication but also reflects a grand astronomical phenomenon that spans 26,000 years, urging us to reconsider our limited understanding of time.
Time Beyond A Human Scale
Currently, I find myself glancing at my clock. Like many, I navigate my life within short time frames, organizing my days and weeks into 24-hour segments. However, time for monuments, celestial bodies, and astronomical cycles operates on a significantly grander scale.
At the Hoover Dam, Hansen evokes a perspective of time that incorporates the materials used by ancient Egyptians, acknowledges their different pole star, and highlights the 26,000-year Precession.
He merged science, art, and creativity, akin to Da Vinci’s use of anatomical and mathematical knowledge in painting The Last Supper.
This fusion of elements creates an artistic masterpiece that not only captivates the eye but also invites contemplation on the fleeting nature of human existence compared to the enduring structures we leave behind.
As noted in the US Bureau of Reclamation guidebook, Hansen acknowledges that while few can navigate a ship or calculate true time, most can read a watch's face. He designed his star chart with this in mind.
This creation exemplifies a rare blend of art, science, and engineering, encapsulating the essence of humanity. Hansen's work challenges our 24-hour cycle mindset, offering a broader perspective of time that resonates with the monumental architecture of Göbekli Tepe, the Great Pyramid, and the Roman Colosseum, even if many overlook it due to the dam's impressive scale.
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