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The Sun Dagger, Herber City, Utah, USA Border SundialsThe sun
Beats the true rhythm
Of time
And the seasons

Robert Perless

To mark the summer solstice on 20th June this year we thought it appropriate to celebrate the dazzling Sun Dagger, an homage to ancient civilizations use of the sun to mark the passage of time

Sun Dagger was created by sculptor Robert Perless for the Wasatch Campus of Utah Valley State College in Heber City, Utah. It functions as a unique celestial observatory, and amplifies the union and synergy of man and nature.

The Sun Dagger, Herber City, Utah, USA Border SundialsRobert says “all my sculptures are meant to make us aware of the energy that surrounds us, but we walk right past in our daily lives without seeing. Sun Dagger helps us discover time in sunlight”.

It is a polar-pointing gnomon horizontal sundial, which also works as a noon transit sundial, and as a seasonal calendar, celebrating the winter and summer solstices and the vernal and autumnal equinoxes with rainbows crossing the sun line.

The gnomon of the sundial faces True North and is elevated at an angle of 40.46 degrees, the latitude of Heber City. Made of welded silicon bronze and polymer prisms, it is 21ft 6” long and stands 13ft 9” high. The dial measures 35ft 10” long from the gnomon to 12 o’clock and 51ft wide.

At solar noon, when the sun crosses the meridian, the ray of sunlight coming through the slit in the gnomon illuminates the 12 o’clock position. Since the sun has a diameter of roughly ½ a degree, the transit lasts several minutes. The prisms on the end of the gnomon project rainbows from the prism array onto the sunshine, crossing it, making the sculpture a seasonal calendar as well as a way to tell time.

The name Sun Dagger comes from the ancient Anasazi who used a shaft of sunlight falling between two stone slabs to mark the passing of the solstice and to read the harvest and planting seasons and record the passage of time.