Did the Vikings use crystal ‘sunstones’ to discover America?
&quot;But without magnetic compasses, like all ancient sailors they would have struggled to find their way once the clouds came over.&quot;<p>&quot;Struggled&quot;, certainly, but Polynesian sailors crossed the Pacific without a compass or sunstone. Quoting <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Polynesian_navigation" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Polynesian_navigation</a> :<p>&gt; Polynesian navigators memorize important facts: the motion of specific stars, so where they would rise and set on the horizon of the ocean; weather and the seasons of travel; wildlife species (which gather at particular positions); the direction, size, and speed of ocean waves; colors of the sea and sky, especially how clouds would cluster at the locations of some islands; and angles for approaching harbours.<p>Quoting from <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Mau_Piailug" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Mau_Piailug</a> concerning the master navigator Mau Piailug:<p>&gt; Prudent navigation relies on no single technique, but instead synthesizes position from multiple inputs. Underway, this constant synthesis makes it easy to spot the navigator—he&#x27;s the one with red eyes from sleep deprivation.<p>I see no reason why the Norse wouldn&#x27;t have had some of the similar navigation skills.<p>That doesn&#x27;t mean they couldn&#x27;t have used a sunstone, but rather that it&#x27;s not unreasonable to believe that they could have navigated with only &#x27;landmarks, birds and whales, and little else&#x27;.