Come explore the art and beauty of science by climbing on, peering through, and observing the many features of our Sunstones II exhibit. Because Sunstones II is a sculpture that also helps us restore our sense of position on the Earth and in the Solar System, we can use it to find the North Star, determine which way is true west, gain height perspective in relation to other key landmarks, and find out when the seasons change, among other things. However, one of the sculpture's features can only be seen at this time of year.
On the Prime Vertical Stone, one of the huge granite slabs of which the sculpture is composed, a large polished hole called the Winter Window can be seen. At noon from the Autumnal Equinox (approximately September 21) throughout winter until the Vernal Equinox (about March 21), the Sun's rays will shine through this hole, casting a beam of light onto the base below. The other half of the year, from spring through summer, the noon sunrays can't pass through. As we approach the Winter Solstice (approximately December 21), when Earth's North Pole is tilted away from the Sun more so than it ever is, the rays of light cast onto the platform will be the longest of the year. And if you were to come to the exhibit at true noon that day (12:08 p.m.) when the Sun is in the south, the Winter Window's shadows of horns line up perfectly with the platform below.
Completed in 1979 by retired UC Berkeley Art Professor Richard O'Hanlon, and altered to allow for astronomical use by Dr. David Cudaback of the UC Berkeley Astronomy Department, Sunstones II overlooks the Bay Area skyline and continues to be an awe-inspiring intersection of art and science.