Yi Xing
The Song Dynasty astronomers of Wei's day still retained the lunar theory and coordinates of the earlier Tang astronomer, mathematician, and mechanical engineer Yi Xing (683-727 AD), which after 350 years had devolved into a state of considerable error. To fix this, Shen and Wei kept similar astronomical records, three times a night over five years, for the orbital path of the moon. Wei and Shen's work was deeply opposed by the officials and fellow astronomers at court, who were offended by their insistence that the coordinates of the renowned Yi Xing were inaccurate. The elite, well-educated ministers and leading astronomers were also insulted by the fact that Wei Pu was born a commoner, yet held more expertise in his field than many of them. When Wei and Shen made a public demonstration using the gnomon to prove the doubtful wrong, the other ministers reluctantly agreed to correct the lunar error. Although correcting the lunar error was a success, the other ministers and officials eventually dismissed Wei and Shen's recorded course plotting of planetary motions, while the court relied upon the inefficient and older model. This meant that only the very worst errors were corrected for planetary motion, and in his disappointment, Shen wrote, "How sad that the backbiting of that bunch of calendar-makers could have kept him from bringing his art to fruition!"