On August 24th, Professor Sun Xiaochun, Executive Deputy Dean of School of Humanities of University of Chinese Academy of Sciences, was invited to deliver an   online academic lecture. The title of this lecture is " The Way of Heaven and Man: Characteristics of Astronomy in Han Dynasty", presided by Professor Zhang Ligang, Executive Deputy Dean of the School of History and Culture of Henan University.

Professor Sun Xiaochun discussed the astronomy of the Han Dynasty from the perspective of the relationship between heaven and man. When explaining the ancient Chinese tradition of telling the people seasons by observing celestial phenomena, he first introduced its importance. Furthermore, through literature and archaeological achievements, he elaborated on the three observation methods. Professor Sun said, the development of astronomy and calendrical system in the Han Dynasty was closely related to the long-term accumulation in the early period. At that time, some previous records reorganized and standardized. Then, Sun Xiaochun added, to some extent, the calendar embodies the unity of the Books of Changes and Spring and Autumn Annals, and it was a model of Union of Heaven and Man. Apart from that, he sorted out the paradigm of the astronomical calendar in the Han Dynasty in detail. Also, Professor Sun Xiaochun gave an account of the corresponding pattern of the heaven and man in the Han Dynasty. Different from the western understanding of the constellation, there was a unique traditional cognition—the constellation was the corresponding pattern to heaven and man. Professor Sun analyzed the correspondence between heaven and man reflected in the documents and unearthed relics of the Han Dynasty from many aspects, and referred to the characteristic of "the unity of heaven and man". In the end, he concluded that astronomy in the Han Dynasty was a typical model of science in ancient China, and the "unity of man and nature" was the most important and distinctive feature of astronomy in the Han Dynasty.

After the lecture, Professor Zhang Ligang made a brief summary. Professor Zhang said that Professor Sun Xiaochun's lecture clearly and concisely expounded on the main contents and characteristics of astronomy in the Han Dynasty, and he also expressed his gratitude to Professor Sun. Professor Sun Xiaochun's lecture was precise in information, rich in content, and the teachers and students benefited a lot. The lecture was a big success.