Chapter 44 Section 4 The North Pole Is Moving, Too

The movement of the solar terms on the ecliptic was indeed discovered and recognized by ancient Chinese astronomers.However, most Chinese astronomers have not paid attention to whether the North Pole is also moving. This is really a major negligence, and it is related to whether people can make scientific explanations and applications for the precession phenomenon. It has long been discovered that several abandoned pole stars can be found in ancient Chinese literature.The first to be abandoned was the right pivot star (α Draconis), the pivotal axis.From its star name, it can be deduced that it served as a pole star.It can be deduced from the modern precession theory that in the third and fourth millennium BC, the right pivot star happened to be located near the North Pole.

Around the 10th century BC, that is, in the Western Zhou Dynasty, the position of the North Pole had moved to the vicinity of Tiandi star (beta Ursa Minor), which is what the "Historical Records·Tianguanshu" said: "Tianji star, one of the bright ones, Taiyi often lives Also." Emperor Star is Taiyi, which is located in the center and is the supreme ruler of the universe.At this time, the Big Dipper is not only the pointer of the construction season, but also the vehicle on which the Tiandi star rides. It runs in the center and travels in all directions. Around 500 A.D., the position of the North Pole was moved to Tianshu (also known as Nius, a certain star in the Camelopard constellation). At that time, people regarded Niu as the true North Pole.But at that time, Chinese astronomy had made great progress, and the instruments used for observation became more and more sophisticated. In the 6th century A.D., the astronomer Zu Wei determined that the distance from the North Celestial Pole to the North Celestial Pole was more than one degree.This discovery is very meaningful. It corrects the previous misunderstanding that the pole star is the north celestial pole, and it also arouses the attention of later generations to the observation of the position of the pole star.

During the Xining period of the Northern Song Dynasty (AD 1068-1077), the astronomer Shen Kuo once presided over the careful observation of Polaris. In order to measure accurate values, he specially calibrated the pivot of the instrument.What he found was that Polaris was more than three degrees away from the North Pole.This observation just shows that the north celestial pole is moving. However, Shen Kuo did not link this discovery with the phenomenon of precession.He once noticed that Zu's observations 500 years ago were inconsistent with his own, but he did not think that the North Pole had moved, but criticized Zu's observations for being imprecise.Shen Kuo's observation results failed to draw the correct conclusion in the end. He just believed that the precession is due to the movement of the ecliptic on the equator, which is exactly the opposite of the fact that the precession is the movement of the equator along the ecliptic.Therefore, although ancient Chinese astronomers have recognized the phenomenon of precession, they have not yet found out the real reason for the precession, nor have they realized that the North Pole is moving, so they have not established the concept of the Yellow Pole, so that the calendar calculation used Yellow longitude and yellow latitude are actually like yellow longitude and yellow latitude.Ancient Chinese astronomers only understood half of the concept of precession, although the other half has been observed, but they have not been able to explain it scientifically.

This historical fact shows that although scientific inventions and creations also have certain contingencies, they are not unrelated to the limitations of the era in which scientists lived.In order to complete the royal mission of astrology and calendar making, ancient Chinese astronomers had to focus on observation and application, and lacked theoretical derivation and research. This is an important reason why they failed to make further progress.The scientific concept of precession was not established until the Ming Dynasty.