Guo Shoujing (1231~1316) was a Chinese astronomer, engineer, and mathematician.

郭守敬(1231~1316)，天文学家、数学家。

His grandfather was Guo Yang, a noted scholar.

其祖父郭荣是著名学者。

By the age of fourteen Guo Shoujing designed a water clock and at sixteen he was studying mathematics.

14岁郭守敬发明了水钟，16岁学习数学，改进了日晷和圭表。在忽必烈的天文台工作，他编制了《授时历》，计算出每年有365.2425天。

He worked on improving the Chinese gnomon and worked at Kublai Khan's observatory. There he formulated the Shoushi calendar and calculated the year to be 365. 2425 days.

这与《格利高里历》是一样的，但是早了将近300年。

This is the Same as the Gregorian calendar, but almost three centuries earlier.

接下来的364年用的都是《授时历》。

It would be used for the next 364 years.

郭守敬还做了与球面三角有关的工作。

He also did work relating to spherical trigonometry.

郭守敬是中国古代著名的水利工程师和数学家。

He is a famous ancient Chinese hydraulic engineer and mathematician.

郭守敬改进了历法，算出每年有365天5小时36分11秒，与精确值只错了50秒。

He improved the calendar and was off by only 50 seconds. He calculated a year was 365 days 5 hours 36 minutes and 11 seconds.

尽管郭守敬在历法上做出很大的成绩，但是他却认为圆周率是3，而不像祖冲之的3.14159265和张衡的3. 142那么精确。

Although he did a great deal on the modern calendar, he suggested pi 3, unlike Zu Chongzhi's 3. 14159265 and Zhang Heng's 3. 142. In engineering he is best known for constructing the artificial Kunming Lake in Beijing as a reservoir and part of a new waterway for grain transport.

在工程学上，郭守敬最著名的是修建了北京昆明湖，用作水库和运粮水路的一部分。

Asteroid 2012 Guo Shou-Jing was named after him.

编号为2012号小行星被命名为“郭守敬星”。