Shen Kuo

Who was Shen Kuo?

Shen Kuo or Shen Gua, courtesy name Cunzhong and pseudonym Mengqi Weng, was a polymathic Chinese scientist and statesman of the Song dynasty. Excelling in many fields of study and statecraft, he was a mathematician, astronomer, meteorologist, geologist, zoologist, botanist, pharmacologist, agronomist, archaeologist, ethnographer, cartographer, encyclopedist, general, diplomat, hydraulic engineer, inventor, academy chancellor, finance minister, governmental state inspector, poet, and musician. He was the head official for the Bureau of Astronomy in the Song court, as well as an Assistant Minister of Imperial Hospitality. At court his political allegiance was to the Reformist faction known as the New Policies Group, headed by Chancellor Wang Anshi.

In his Dream Pool Essays of 1088, Shen was the first to describe the magnetic needle compass, which would be used for navigation. Shen discovered the concept of true north in terms of magnetic declination towards the north pole, with experimentation of suspended magnetic needles and "the improved meridian determined by Shen's [astronomical] measurement of the distance between the polestar and true north".