Researchers have determined that what seemed like just stories of Vikings using crystals to be able to navigate in cloudy weather may have been true. Using computer simulations, scientists looked at assumptions about what those crystals may have been. They determined that it was possible to navigate using crystals in cloudy weather.
Vikings didn't need compasses to make it through the Atlantic on their journey.
Viking Sunstones
Researchers from ELTE Eötvös Loránd University in Hungary used computer simulations to be able to determine the veracity of the stories behind Viking navigation. A journey between Norway and Greenland would have taken three weeks via longboat. During these journeys, there were stories that Vikings used a sunstone during cloudy weather to be able to use their sun compasses, which worked with shadows.
In the paper published in Royal Society Open Science, scientists outlined how the simulations were able to confirm that sunstones could be used to navigate the Atlantic during cloudy weather. Previous research determined that Vikings used a sun compass to navigate. Old stories said that they used sunstones during cloudy weather as their compasses. One problem is that no sunstone has ever been found.
During the investigation on a 16th-century English shipwreck in 2002, a crystal was found on the ship. It was possible that these English sailors obtained the knowledge of using crystals to find their way around from the Vikings, but this link hasn't been proven.
The study is based on the assumption that this sunstone was possibly a crystal. This is supported by the fact that crystals such as calcite, cordierite, and tourmaline have the ability to split sunlight into two beams even when it is cloudy. That same crystal also reveals the polarized rings around the sun, which shows its placement in the sky.
Testing The Crystals
Researchers Dénes Száz and Gábor Horváth say that the crystals haven't been tested before during journeys because of the unreliability of the weather and the small samples of results that they would produce. Instead, they opted to run computer simulations of the trips between Norway and Greenland.
For the simulations, they chose to run the trips between two specific days: spring equinox and summer solstice. They ran the simulations 36,000 times and found that it would be possible to use crystals to navigate between the two locations.
Though they report that the results were mixed, they largely depended on what type of crystal was used and how often the crystal was used. They found that using a cordierite crystal every three hours was 92.2 to 100 percent accurate.
They also calculated that if they used calcite crystals every four hours or more, they might've missed Greenland and landed in Canada instead.
During the simulations, researchers assumed that no strong winds or storms would blow the ship off course.
