Thanks to "GRS Science Club" for making me aware of this sculpture by posting (
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From the Arts Inventory site:
"The southernmost part is a bronze sphere mounted on a granite pedestal set in a circular basin of granite pavers with a concrete wall. There is an iron grate halfway over the top of the basin. The water collects in the basin and overflows onto a spillway of granite pavers, then drains through a grate. The basin is set into a circular plaza of brick and concrete pavers wiht (NOTE: s/b "with") a brick wall halfway around. North of this is a granite and bronze spire, seven-sided, in progressively smaller sections. It is set into granite pavers. Directly north of the spire are three bronze domes lined up on a north-south axis with hemispherical grates on to. The water bubbles up into the grates, out over the domes and down into flat grates around the base.
Dimensions: approx. H. 40 ft. x D. 80 ft. x Diam. 125 in.
The artist received a 250,000 dollar public arts commission from the University of Illinois for the creation of this piece. IAS files contain copies of the Champaign-Urbana News Gazette (Champaign, IL), June, 22, 1991 and Champaign-Urbana News Gazette (Champaign, IL), June 28, 1990, both discussing the astronomical functions of the piece. Looking through the tube in the bronze sphere at night, the light from the North Star is seen lighting up the spire's tip."
From (
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"Upwells is essentially a large sundial. The tall spire is the gnomon, and the courtyard itself forms the surface on which the shadow is seen. Dome-shaped fountains are placed at certain critical points on the plaza, although no other markings are provided. Notice that this sculpture has an additional feature, a method for sighting the north celestial pole and the star Polaris.
You will need to visit the sculpture on two occasions and make measurements of the shadow cast by the gnomon. You will then use those measurements to determine the time of local noon. With some additional information you will calculate your latitude, the radius of the Earth, and the tilt between the Earth's equator and the plane of the solar system.
Remember that Upwells is, first and foremost, a work of art. As such it is not optimally designed for astronomical measurements. In particular, the shape of the gnomon is such that the shadow it casts is not sharp and well defined. Do the best you can in estimating the position of the shadow. "