Apr 8, 2018 05:57 PM
http://www.sciencemag.org/news/2018/04/v...y-crystals
EXCERPT: . . . For decades, researchers have suggested that enigmatic “sunstones” mentioned in Viking tales [...] were the key to navigating under less-than-sunny skies. The sunstones of legend could identify the sun’s location even if it was occluded by clouds; however, no such stones have been found in the handful of Viking shipwrecks that exist. “This is all speculation, really,” says Stephen Harding [...] who wasn’t involved in the new study. But he notes that possible evidence of sunstones exists [...]
Navigating with crystals isn’t necessarily New Age hooey. Several types of minerals—especially ultrapure crystals of calcite, cordierite, and tourmaline—can split a beam of sunlight to form two images, with polarized light taking a slightly different path than the main beam. By looking at the sky through such a crystal and then rotating it so the two images are equally bright, it’s possible to spot the rings of polarized light that surround the sun, even under cloudy skies. Identifying the sun’s location would give mariners a sure point of reference during long sea journeys. But could such a technique work in practice? Previous studies suggest the answer is yes...
MORE: http://www.sciencemag.org/news/2018/04/v...y-crystals
EXCERPT: . . . For decades, researchers have suggested that enigmatic “sunstones” mentioned in Viking tales [...] were the key to navigating under less-than-sunny skies. The sunstones of legend could identify the sun’s location even if it was occluded by clouds; however, no such stones have been found in the handful of Viking shipwrecks that exist. “This is all speculation, really,” says Stephen Harding [...] who wasn’t involved in the new study. But he notes that possible evidence of sunstones exists [...]
Navigating with crystals isn’t necessarily New Age hooey. Several types of minerals—especially ultrapure crystals of calcite, cordierite, and tourmaline—can split a beam of sunlight to form two images, with polarized light taking a slightly different path than the main beam. By looking at the sky through such a crystal and then rotating it so the two images are equally bright, it’s possible to spot the rings of polarized light that surround the sun, even under cloudy skies. Identifying the sun’s location would give mariners a sure point of reference during long sea journeys. But could such a technique work in practice? Previous studies suggest the answer is yes...
MORE: http://www.sciencemag.org/news/2018/04/v...y-crystals