Biography:Li Fan (Han dynasty)
Li Fan (Chinese: 李梵; pinyin: Lǐ Fàn) was a Chinese astronomer during the Han Dynasty (202 BC-220 AD). He noticed that the Moon does not move uniformly through its phases by using background stars as reference.[citation needed] In 85 Li Fan and Bian Xin (Chinese: 編訢) were tasked by Emperor Zhang to resolve inaccuracies in the Taichu calendar.[1][2] He is also known to have worked with inflow clepsydras as opposed to earlier, typically less accurate outflow clepsydras.[3]
The measurements of synodic periods of the planets given in the following table are attributed to him.[4]
| Planet | True value (days) | Li Fan's value (days) |
|---|---|---|
| Mercury | 115.877 | 115.881 |
| Venus | 583.921 | 584.024 |
| Mars | 779.936 | 779.532 |
| Jupiter | 398.884 | 398.846 |
| Saturn | 378.092 | 378.059 |
An impact crater that is located at the Phaethontis quadrangle, Mars, 47.2°S Latitude and 153.2°W Longitude was named in his honor. The diameter of the impact crater is approximately 104.8 km.
References
- ↑ Crespigny, Rafe de (2007) (in en). A Biographical Dictionary of Later Han to the Three Kingdoms (23-220 AD). Leiden: Brill. pp. 410. ISBN 9789047411840. https://books.google.com/books?id=49OvCQAAQBAJ&pg=PR9.
- ↑ Cullen, Christopher (2017) (in en). The Foundations of Celestial Reckoning: Three Ancient Chinese Astronomical Systems. Routledge. pp. 139, 377. ISBN 9781138101173. https://books.google.com/books?id=IT9DjwEACAAJ.
- ↑ Needham, Joseph (1959) (in en). Science and Civilisation in China: Volume 3, Mathematics and the Sciences of the Heavens and the Earth. Cambridge University Press. pp. 320. ISBN 9780521058018. https://books.google.com/books?id=jfQ9E0u4pLAC.
- ↑ 4.0 4.1 Needham, Joseph (1959) (in en). Science and Civilisation in China: Volume 3, Mathematics and the Sciences of the Heavens and the Earth. Cambridge University Press. pp. 401. ISBN 9780521058018. https://books.google.com/books?id=jfQ9E0u4pLAC.
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