Gadgets

How Did Vikings Navigate? Sunstones, Say Historians

Being a bit of an ancient history buff (I know, really, on top of everything else), the stories of Vikings sailing all over the place using just a sun dial always made me wonder: How’d the do that sort of thing if they couldn’t see the sun? On the open ocean, not a landmark to be see under an overcast cloudcover, how do you navigate? It may actually be sunstones after all, according to a New Scientist article recently published.

Sunstones are see-through crystals of minerals like calcite that act as natural filters, polarizing light. The light’s photons only vibrate on one plane, and this makes rings appear as the light shines through the mineral.

The theory is that even on cloudy days the polarization of light would occur through the sunstone, making navigation possible on overcast days as once the sun’s position was noted a torch could be used to discern direction over a sundial.

Did it work? It hasn’t actually been demonstrated and is being investigated still, but if it does work as it’s rumored, it’s one more mystery solved.

[via New Scientist]