It has been very helpful in the sky-polarization Viking navigation for sailors even in cloudy meteorological conditions.
In a paper titled Royal Society Open Science, Gábor Horváth and Dénes Száz, the staff of the Department of Biological Physics at the Eötvös Loránd University (ELTE) Laboratory of Environmental Optics, have presented the latest results of their research of about one and a half decades of Viking marine navigation.
According to the legend, special crystals called sunbathers could help the Vikings in marine navigation, the researchers of ELTE have already demonstrated in a study published last year that it was possible to look at the so-called sunset over cloudy weather.
The Vikings had made thousands of miles in the sea at this time, and they even went to North America. They did not have a magnetic compass, so they were informed by the Sun. If clouds covered the sky, the sun was set up with so-called sunbeds, and then the north direction was determined.
Danish archeologist Thorkild Ramskou assumed in 1967 that the rocks were polarized filter crystals – probably calcite, tourmaline or cordierite – and used to analyze the polarization of the skylight, from which the sun-covered sun could be inferred.
Using the data of their previous research with solar crystals, ELTE researchers simulated thousands of sea routes between Norway and Greenland at latitude 60 degrees below cloudy meteorological conditions during the summer solstice and the spring equinox, and found the chances of Viking sailors coming from different meteorological conditions, within a three-week trip to Greenland. Simulations were performed with different crystals and different time intervals.
“Its results show that sky polarization navigation is surprisingly successful even in the spring equinox and on the day of the summer solstice even under cloudy conditions, when the navigator regularly determines the north direction at least every three hours irrespective of the type of sunset used by the sky polarization analysis “, researchers said in their study.
“This explains why the Vikings have been able to rule the Atlantic for 300 years and reach the North American coasts without a magnet,” he added.
“Our results indicate that not only the periodic repetition of navigation is important for successful navigation, but also the symmetry of time distribution when navigating. Our research is currently the most detailed and accurate measurement of sky polarization navigation that can be achieved without this the method would be tested directly in the seas, “reads the study.
Source: MTI / Picture: napi.hu /