Zu Chongzhi

Zu Chongzhi

Zu Chongzhi (429-500) was an outstanding mathematician and astronomer during the Northern and Southern dynasties (420-589). He devoted his life to the study of natural sciences and made remarkable contributions to mathematics, astronomy, calendrical calculations, and mechanical engineering.

Zu was the first to calculate the value of pi to an accuracy of seven decimal places, between 3.1415926 and 3.1415927, which was a major contribution to China and the world. His calculation of Pi was later named after him as "Zu Chongzhi's Pi", and this record in accuracy was not surpassed until the 16th century. In addition, the "Daming calendar" Zu compiled was the most accurate calendar at that time. His calculation of the length of a tropical year differs from the modern value by only 46 seconds; it laid solid foundations for astronomical research worldwide.

To celebrate Zu Chongzhi's remarkable contributions to science and culture, the Purple Mountain Observatory named an asteroid – which was discovered in 1964 and given the international permanent number 1888 – "Zu Chongzhi Star".

祖冲之

祖冲之（429—500）是南北朝时期杰出的数学家、天文学家。他一生钻研自然科学，在数学、天文历法和机械制造等方面都作出了卓越的贡献。

祖冲之首次将圆周率精算到小数点后第七位，即在3.1415926和3.1415927之间。他对圆周率数值的精确推算值，对于中国乃至世界是一个重大贡献，后人将“这个精确推算值”用他的名字命名为“祖冲之圆周率”。直到16世纪，这一精算纪录才被打破。此外，由祖冲之撰写的《大明历》是当时最科学、先进的历法。按照他的推算，一个回归年的长度和今时的推算值仅相差46秒，这为世界天文研究奠定了坚实基础。

为了纪念祖冲之对中国和世界科学文化作出的杰出贡献，紫金山天文台将1964年发现的国际永久编号为1888的小行星命名为“祖冲之星”。