Viking "sunstone"
It has been speculated that the sunstone (Old Norse: sólarsteinn; a different mineral than the gem-quality sunstone) mentioned in medieval Icelandic texts was Iceland spar and that Vikings used its light-polarizing property to tell the direction of the sun on cloudy days, for navigational purposes.
In 2007, Ramón Hegedüs and his colleagues from Eötvös Loránd University in Budapest, Hungary, confirmed that the polarization of sunlight in the Arctic can be detected under cloudy conditions. Their research is reported in "The Proceedings of the Royal Society." Further research in 2011 by Ropers et al., confirms that identifying the direction of the sun to within a few degrees in both cloudy and twilight conditions was possible using the sunstone and the naked eye. The process involves moving the stone across the visual field to reveal a yellow entoptic pattern on the fovea of the eye. The recovery of an Iceland spar sunstone from the Elizabethan ship Alderney that sank in 1592 suggests that the navigational technology may have persisted after the invention of the magnetic compass.
Read more about this topic: Iceland Spar
Famous quotes containing the word viking:
“Rice and peas fit into that category of dishes where two ordinary foods, combined together, ignite a pleasure far beyond the capacity of either of its parts alone. Like rhubarb and strawberries, apple pie and cheese, roast pork and sage, the two tastes and textures meld together into the sort of subtle transcendental oneness that we once fantasized would be our experience when we finally found the ideal mate.”
—John Thorne, U.S. cookbook writer. Simple Cooking, “Rice and Peas: A Preface with Recipes,” Viking Penguin (1987)