t opside V olume 120 , I s s u e 2
P a ge 22
An Auxiliarist Explores Sunstone Navigation
by Tim Marks photos and graphic by COMO Joseph Giannattasio
In the end , the real magic of the sunstone is not in its mystical properties , but in the ingenuity of the Vikings themselves . They were able to adapt and innovate in ways that are still inspiring today . As Commodore Giannattasio notes , “ Using a sunstone to navigate for Auxiliary surface patrols is not likely to be authorized by district Operations Training Officers .” Nonetheless , the legacy of the Vikings lives on , and their achievements continue to inspire and amaze us .
References :
Voyages To Vinland - The First American Saga Newly Translated And Interpreted - Einar Haugen
Success of sky-polarimetric Viking navigation : revealing the chance Viking sailors could reach Greenland from Norway - research article by Dénes Száz and Gábor Horváth
Icelandic spar , also called optical calcite , from Iceland is used in demonstrating the polarization of light with a strip of tape on one side .
The sunstone directed away from the sun during civil twilight ( the moment the sun slips below the horizon ) - the projected images are different shades .
Birefringence is the double refraction of light in a transparent material . Iceland spar ' s birefringence is so large that a calcite crystal placed over a printed line on a page projects two distinct images of the line . .
The sunstone pointed in the direction the sun during civil twilight - the projected images are the same shade ..