What is the oldest existing observatory in China?

According to the rich astronomical historical records in China, Dengfeng Stargazing Observatory is the oldest existing observatory in China.

Dengfeng Stargazing Observatory, located in Dengfeng City, Henan Province, is a multifunctional observatory. It was designed and manufactured by the outstanding astronomer Guo Shoujing. Ancestors not only used it to measure shadows, but also used it for astronomical research such as stargazing and timing. It was built in the early Zhou Dynasty, about 1 1 century BC, and it is still preserved by the "Guo Gong Pian". This observatory has a history of more than 365,438+000 years, which is earlier than the oldest existing observatories abroad, namely the Alexandria Observatory and the Rhodes Stargazing Observatory. Therefore, it is the oldest existing observatory in the world, not only in China.

The main purpose of the stargazing platform is to measure shadows, which is similar to the standard function of measuring sun shadows. The tower building is regarded as a pole standing upright on the ground, and the "ruler" used to measure the length of the sun shadow is represented by the "long embankment" just north of the stage. There is also a beam above the stargazing platform on the top of the two small houses, which contains a leaky kettle and an armillary sphere. Every noon, the sun will cast the shadow of the beam on the top of the platform on the "ruler". It can be seen that the noon projection from winter to Sunday is the longest, and that from summer to Sunday is the shortest. From the solstice of one winter (or the solstice of summer) to the next winter is the length of a tropical year. This is the method used by China to measure the length of a year in ancient times, and this method also laid the foundation for specifying the calendar.

According to the historical data "History of the Yuan Dynasty", Polaris was observed here during the "Four Seas Examination" in the early Yuan Dynasty, so the observatory can not only measure the sun shadow, but also have other functions, such as observing images. There may have been some facilities for observing images on the observatory in those days.

In addition, its designer Guo Shoujing and others have made great achievements through field experiments on the stargazing platform. He not only mastered the running laws of the sun, the moon, the stars and the earth, but also clearly summed up that there are 24 solar terms in a year, which has made important contributions to human production and life.

It can be said that the stargazing platform is an important legacy of astronomy in China and a symbol of the Chinese nation.