Precession of the Equinox Circles

Precession of the Equinox Circles
36.016666, -114.738831 Hoover Dam, Lake Mead Nevada. on 02/19/2019 

The Hoover Dam hides an intriguing secret connecting sky to ground and past to present, using a similar “as above, so below” system of measuring time displayed at the Giza Pyramid of Egypt.

Located on the Nevada side of the Hoover Dam is an monument dedicated to over 100 workers who lost their lives to the construction of  the Hoover Dam.

Greeting visitors are two huge sculptures of winged celestial beings and the base with inscriptions, but not many people notice that the monument sits on top of a celestial map.

"Winged Figures of the Republic" on the Nevada side of the Hoover Dam 02/19/2019

This celestial map is embedded around the monument. It is a beautifully executed representation of the night sky for a specific day and time and it includes many decorative features, astronomical markings and curious labels.

Back in 1930s, when this was designed, only an astronomer could have made sense of this information; but today, thanks to computers and applications like Stellarium, this knowledge is available to the average person. Aligning structures to constellations or fixed points was common in the past.

What is unique about the Hoover Dam sky map is the beauty of the design and precision employed by its creator, Oskar Hansen.

According to Hansen, the reason for this monument and star map is –

to preserve for future generations the date on which President Franklin D. Roosevelt dedicated the dam and the power plant.”

Hansen encoded information in his masterpiece that relates to and preserves a very specific place and moment in time:

PLACE (Hoover Dam)
YEAR (1935)
MONTH (September)
DAY (30th)
TIME (21:30)
But how did he do it?

The phenomenon results from the wobbling of the Earth’s axis, mostly to the mass of the Moon. An observer on the surface of the spinning Earth looking east at sunrise would see different stars rising at different times, the result being that over 25,920 years, the entire circle of the 12 constellations of the Zodiac will successively appear on the horizon at very predictable intervals. Approximately every 2,150 years (25,920 /12), a new constellation will rise.

The second place to look is north, to see the Pole Star, a different face on our clock. If you attached a laser to the axis of the Earth’s rotation, it would trace a giant circle on the celestial sphere. Stars which are on or near this circle successively become “pole stars” over a period of approximately 26,000 years. Currently, in the Northern Hemisphere, Polaris is the north star, but in 12,000 years, the axis will point to Vega. Neat.

Man’s control over natural forces has grown in proportion to his increasing knowledge of the true nature of the Universe of which we are a part…Time, the intangible governor of all our acts, is measured to us by the external relations of our Earth to other worlds. 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.
The designer of the star chart…placed the bodies of our solar system in the terrazzo, correct to the minutest fraction of an inch in scale of the design. One versed in the abstruse mathematics of astronomy may calculate the precession of the Pole Star for the next 14,000 years by studying the design of the star chart. Conversely, future generations may look upon this monument and determine – if no other means are available – the exact date on which engineers and craftsmen of our generation completed this giant structure”.

I think it is fascinating that this piece of archeological history resides in the United States. It is a shame that there are not more structures, symbols and memorials that will stand the test of time for future generations to look back on.