This could help to explain how the Vikings were able to navigate across large tracts of the sea - well before the invention of the magnetic compass.

BBC: 'Viking sunstone' found in shipwreck

But the scientists conjecture that use of sunstones may have persisted for many centuries as a back-up to the often unreliable magnetic compass, which was introduced in Europe in the 13th Century.

BBC: 'Viking sunstone' found in shipwreck

What our man Pascal Brisset did is design a Linux system around a Gumstix Overo Fire computer-on-module, a Vuzix VR920 head-mounted stereoscopic 640 x 480 display (complete with 3D tilt sensor and 3D magnetic compass), WiFi, and Bluetooth modules -- the whole shebang resides in (and on) the eyewear, just the thing for secure telepresence and augmented reality applications (or just extra-private web browsing).

ENGADGET: Homebrew head-mounted Linux system for telepresence, looking silly

They moved often, living near Byron Bay, a beachfront community in New South Wales, and on Magnetic Island, a tiny pile of rock that Captain Cook believed had magnetic properties that distorted his compass readings.

NEWYORKER: No Secrets

The Geographic pole is the top of the axis on which the earth spins, the Magnetic pole is where the compass points to, and the Arctic pole is the point on the Arctic Ocean furthest from any land.

BBC: NEWS | UK | British man scores polar success

Another added feature is the on-board Magnetic Sensor that lets the user take advantage of downloadable e-Compass apps.

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