Su Song was a Chinese polymath and statesman who lived during the Song dynasty, from 1020 to 1101. Renowned for his contributions to various fields, he is particularly known for his work in astronomy, engineering, and cartography. Su Song's most famous achievement was the design and construction of his Astronomical Clock Tower in the city of Kaifeng.

This impressive device incorporated numerous intricate instruments that many in the Western world assumed had not made it to China, including an early escapement mechanism and the oldest known chain drive (called the “celestial ladder” by Su Song), to track movements of celestial bodies and tell time accurately, all of which were detailed in his 1092 treatise Xinyi Xiangfayao.