The Vikings, the "sun stone" and the polarization of light

The Vikings knew they move through the "sun stone" during their famous ecapades? One theory is often raised and debated, the Vikings were moving according to the position of the sun they could determine, even in cloudy weather, with this stone which is capable of polarizing light.

• Vikings can't use transition tag on Sidney Rice (22/02/2011)
• Vikings' crystal clear method of navigation (31/01/2011)
• Vikings plan lockout practices (21/02/2011)
• Vikings face a potential talent drain this offseason (21/02/2011)
• Vikings place franchise tag on Chad Greenway (21/02/2011)

Viking (wikipedia)