Tag Archives: Pi

Zu Chongzhi’s birthday

Zu Chongzhi (429-501) is one of the greatest ancient Chinese mathematicians. He was taught Mathematics from Liu Hui’s commentary on the Nine Chapters on the Mathematical Art. He was appointed as an officer in the city of Yang-chou and during this time he worked in Arithmetic and Geometry. He gave the rational 355/113 as an approximation of pi in his Zhui shu (“Method of interpolation”) and proved that:

3,1415926 < pi < 3,1415927

Zu also proposed a new calendar (the “Calendar of Great Brightness”) in 462 based on a cycle of 391 years with 144 extra months inserted (=4.836 months).

In the Wikimedia Commons there is this photo of a statue dedicated to him in Tinglin Park in Kunshan.

Source: Wikimedia Commons

Google dedicated this doodle five years ago to celebrate his birthday.

Location: Tinglin Park in Kunshan (map)


Pi Day’s doodle

Today is Pi Day!

Google published this doodle four years ago. We can see some formulas in it related with circles, spheres, trigonometry and the Archimedian value of pi.

Pi is the guest star

Monument dedicated to Pi in Seatle
Source: Google Street View

One day by chance I discovered a Micajah Bienvenu’s sculptural work and I suppose that the picture that I had is due to the will of Destiny… I noticed that Pi was the great guest star of one of his sculptures! Reminding that discovery, I began to search in the net and I found that this Pi is or was installed at Harbor Steps in Seattle, near the corner of University St. and the 1st Avenue. However, I have not been able to discover whether the monument is still there or has been moved to another place because the author’s website says nothing about it.