May Speaker: Viking Sunstones in Saga and Science

by Cindy Schmidtlein, MSDC Vice President

Our speaker for May is Dr. Jennifer Lynn Bartlett, the Kinnear Chair in Physics at the U.S. Naval Academy, where her research focuses on predictions of natural light available for twilight and night-time operations. She is a trained celestial navigator who has made five training voyages with Coast Guard cadets. She is also active in the history of astronomy research. Therefore, she took Iceland Spar with her on a two-month Arctic voyage.

“Then the king made them fetch the solar stone and held it up and saw where light radiated from the stone ….”

From such minor threads in Iceland literature is the legend of the sunstone woven. Did the Vikings have such a navigational aid as they raided Europe and Asia? Did such a stone make their voyages to North America possible? After Christianization, did such stones supplement sundials in tracking the work and prayers of monks in the far north?

Scientific speculation suggests the polarizing powers of Iceland Spar or cordierite, or a similar mineral, might underlie the stories.  However, modern studies of the effectiveness of such minerals in locating the Sun under a variety of sky conditions have had mixed results. Could it be? Yes. Was it? We may never know.