Wat Phra Ngam，大城府历史公园，泰国 Wat Phra Ngam, Ayutthaya Historical Park, Thailand (© boonchai wedmakawand/Alamy Stock Photo)

Wat Phra Ngam，大城府历史公园，泰国 Wat Phra Ngam, Ayutthaya Historical Park, Thailand (© boonchai wedmakawand/Alamy Stock Photo)

一个π A piece of pi

圆周率日快乐!

有人这样说过，世界上唯一不变的是变化。然而，在数学里却有许多固定不变的常数，今天，我们要庆祝的也许是其中最著名的一个：π。圆周率是圆的周长与直径之比，约为3.14159。每年的3月14日，全世界的数学爱好者都会用烘焙来庆祝圆周率π日——这既是对数学常数π的庆祝，也是对其同音字，美味的“派”的庆祝。它始于1988年，当时物理学家拉里·肖将日期（3/14）与这个常数的前三位数联系起来。今天，数学家和爱好者们用吃派和背诵π来庆祝圆周率日。你知道吗，当你的时钟敲响1:59时，表示你离圆周率的实际值又近了三位小数。圆周率无处不在，甚至在大自然中也是如此。图中是泰国大城府寺庙的一棵菩提树，其形状就像圆周率的符号。无论你是数学怪才，还是只是为了享受美食，每个人都可以享受“派”节！

Happy Pi Day!

They say the only constant in life is change. In mathematics, however, there are many constants and today, we're celebrating perhaps the most famous of them all: pi. Represented by the symbol π, this tasty-sounding number is the ratio of a circle's circumference to its diameter, approximately 3.14159. Every March 14, mathematics fans across the world get baking to mark Pi Day with a pie. It began in 1988, when physicist Larry Shaw connected the date (3/14) with the first three digits of π. Today, mathematicians and enthusiasts celebrate Pi Day with pie eating and pi reciting. Did you know that when your clock strikes 1:59 today, you will be three decimal places closer to the real value of pi? Pi is everywhere, even in nature. Pictured here is a bodhi tree which has grown over an arch into the shape of the pi symbol at Wat Phra Ngam, a temple in Ayutthaya, Thailand. Whether you're a math geek or just in it for the treats, Pi Day is for everyone to enjoy!