From the northern coast of Kingdom of Norway to the southern coast of Ukraine runs a chain of survey triangulation points that together forms the Struve Geodetic Arc. It stretches from Hammerfest (Norway) on the shores of the Arctic Ocean to Nekrasivka (Ukraine) past times the Black Sea , a distance of 2 ,820 km , snaking inward together with out of numerous territories , that today belong to 10 unlike countries. The arc was established past times the German-born Russian scientist Friedrich Georg Wilhelm von Struve , who undertook a thirty-nine-year-long survey , betwixt 1816 together with 1855 , to decide the shape together with size of the earth. The survey yielded the outset accurate standard of a meridian arc , which inward plough allowed the outset precise standard of the earth’s diameter.
The northernmost station of the Struve Geodetic Arc is located inward Fuglenes , Norway. Photo credit: Francesco Bandarin/Wikimedia
The conclusion of the size together with shape of the basis was 1 of the most of import problems for natural philosophers since the ancient times. In the 2d century BC , Greek astronomer together with mathematician , Eratosthenes , developed a method to decide the radius of the basis past times measuring a part of a meridian arc together with comparison that length to the corresponding angle subtended at the Earth’s center. If 1 knows the arc length together with the cardinal angle , the radius tin give notice last easily calculated.
Eratosthenes calculated the arc length past times measuring the fourth dimension it took for caravans to cross the desert. The angle was determined past times measuring the departure betwixt the tiptop of the Sun betwixt the latitudes. Although the accuracy of his measurements were depression , Eratosthenes was able to calculate the earth’s radius alongside an accuracy of 1%. For 2 K years , Eratosthenes’ “method of grade observation” remained the most promising method of determining the size of the earth. What improved was the methodology of measurement.
Map of the Struve Geodetic Arc where carmine points position the World Heritage Sites.
In the 16th century , a novel standard technique called “triangulation” was developed using which solely brusk distances were needed to last measured accurately , piece long distances could last determined using a chain of connected triangles. Triangulation enabled astronomers together with cartographers to accurately stair out long distances that stretched for hundreds together with thousands of kilometers.
During the 18th century , many arcs were constructed around Europe , only Struve’s arc was the longest such arc when it was created , together with remained hence for over a century. It was also the most accurate , producing standard that was off past times solely iv mm for every 1 km. In other words , using Struve’s arc the radius of the basis was calculated to inside 223 meters of its actual value.
The Struve Geodetic Arc originally consisted of 258 triangles connecting 259 triangulation points. At the fourth dimension of its creation , the arc passed through 2 countries —Union of Sweden-Norway together with the Russian Empire. But changes inward the political boundaries bring directly scattered the points across 10 nations —Norway , Sweden , Republic of Finland , Russian Federation , Republic of Estonia , Republic of Latvia , Republic of Lithuania , Republic of Belarus , Ukraine together with Moldavia. The points or stations are marked inward diverse ways — some are holes drilled inward rocks , some are crosses marked on the stone surface , others are cairns built out of rocks. Some stations also had commemorative monuments erected.
Out of the master copy 259 , 34 stations were collectively inscribed nether the UNESCO World Heritage Sites list.
A Struve Geodetic Arc station inward Latvia. Photo credit: Jānis U./Wikimedia
A Struve Geodetic Arc station inward Hogland , Russia. Photo credit: Islander/Wikimedia
A Struve Geodetic Arc station inward Alta , Norway. Photo credit: aoiaio/Wikimedia
A Struve Geodetic Arc mark at Tartu Old Observatory inward Tartu. Photo credit: Graham Stone/Flickr
A Struve Geodetic Arc station inward Lithuania. Photo credit: Stefan Krasowski/Flickr
Sources: Wikipedia / Heritage of Astronomy / UNESCO / Euro Geographics