Math lovers celebrate Pi Day on March 14, or 3/14. Around the world, many people even mark the day by eating a tasty piece of pie. 

数学爱好者会在 3 月 14 日（即 3 月 14 日）庆祝圆周率日。 在世界各地，许多人甚至通过吃一块美味的馅饼来纪念这一天。 

For those who do not know, pi is a mathematical constant, a value that never changes. It expresses the ratio of a circle’s circumference (the distance around the circle) to its diameter (the distance across the circle, passing through its center.) 

对于那些不知道的人来说，圆周率是一个数学常数，一个永远不会改变的值。 它表示圆的周长（围绕圆的距离）与其直径（穿过圆的距离，穿过圆心的距离）的比率。 

The approximate value of this mathematical constant is 3.1415926535. But those are just the first 10 digits of pi. The numbers go on infinitely, or forever. 

该数学常数的近似值为3.1415926535。 但这些只是 pi 的前 10 位数字。 这些数字无限地持续下去，或者永远持续下去。 

Pi can calculate the circumference of a circle by measuring the diameter and multiplying that by the 3.14-plus number. The formula has been used in physics, astronomy, engineering and other fields, dating back thousands of years. 

Pi 可以通过测量直径并将其乘以 3.14+ 的数字来计算圆的周长。 该公式已被应用于物理学、天文学、工程学等领域，其历史可以追溯到数千年前。 

Long before computers, scientists such as Isaac Newton spent many hours calculating decimal places by hand. But today, researchers use computers to come up with trillions of digits for pi. But there is no end. 

早在计算机出现之前，艾萨克·牛顿等科学家就花了很多时间手工计算小数位。 但今天，研究人员使用计算机计算出数万亿位的圆周率。 但没有尽头。

There are many uses for pi. 

pi 有很多用途。 

The number helps calculate the size of paper rolls used in printers. And it helps decide the necessary size of a container that serves heating and air conditioning systems in buildings of different sizes. 

该数字有助于计算打印机中使用的纸卷的尺寸。 它有助于确定为不同规模的建筑物中的供暖和空调系统提供服务的容器的必要尺寸。 

Scientists use the number to point an antenna toward a satellite and calculate the orbits and positions of planets and other space bodies. 

科学家利用这个数字将天线指向卫星，并计算行星和其他空间物体的轨道和位置。 

Scientists with the American space agency NASA use pi to calculate when parachutes should open as a vehicle splashes down on Earth or lands on Mars. 

美国航天局 NASA 的科学家使用 pi 来计算当飞行器降落在地球或登陆火星时降落伞应该打开的时间。

In 1706, British mathematician William Jones began using the Greek letter pi for the number 3.14… It is the first Greek letter in the words “periphery” and “perimeter.” Both words have similar meanings as circumference. 

1706年，英国数学家威廉·琼斯开始使用希腊字母pi来表示数字3.14……它是“外围”和“周长”一词中的第一个希腊字母。 这两个词与周长具有相似的含义。 

Pi Day itself dates back to the year 1988. That was when physicist Larry Shaw began celebrations at the Exploratorium, a science museum in San Francisco, California. 

圆周率日本身可以追溯到 1988 年。当时物理学家拉里·肖 (Larry Shaw) 在加利福尼亚州旧金山的科学博物馆探索博物馆 (Exploratorium) 开始庆祝活动。 

The so-called holiday did not gain national recognition until more than 20 years later. In 2009, the U.S. Congress declared every March 14 to be Pi Day as a way to bring more interest in math and science. 

这个所谓的节日直到20多年后才得到全国的认可。 2009 年，美国国会宣布每年 3 月 14 日为圆周率日，以提高人们对数学和科学的兴趣。 

The San Francisco museum that started the holiday organizes events, including a walk around a circular sign, called the Pi Shrine, 3.14 times. Of course, there is also plenty of pie to eat. 

节日开始的旧金山博物馆组织了一些活动，包括绕着一个名为“Pi 神社”的圆形标志散步 3.14 次。 当然，还有很多馅饼可以吃。

Many Pi Day events take place at colleges in the United States. For example, Nova Southeastern University (NSU) in Florida holds the “Mental Math Bingo” game with free pizza pies. 

许多圆周率日活动在美国的大学举行。 例如，佛罗里达州诺瓦东南大学（NSU）举办“心理数学宾果”游戏，并提供免费披萨饼。 

Jason Gershman oversees NSU’s math department. He said, “Every year, Pi Day provides us with a way to celebrate math, have some fun and recognize how important math is in all our lives.” 

贾森·格什曼 (Jason Gershman) 负责管理新西伯利亚州立大学 (NSU) 的数学系。 他说：“每年，圆周率日都为我们提供了一种庆祝数学、享受乐趣并认识到数学在我们生活中的重要性的方式。” 

NASA has its yearly “Pi Day Challenge” online. The space agency offers games and puzzles, such as calculating the orbit of an asteroid or the distance a moon rover would need to travel each day to study a certain lunar area. 

美国宇航局 (NASA) 在网上举办了一年一度的“圆周率日挑战”。 该航天局提供游戏和谜题，例如计算小行星的轨道或月球车每天需要行驶以研究月球某个区域的距离。 

If you still wonder why Pi Day is such an important day for math lovers, here are two more reasons: Albert Einstein, possibly the world’s best-known scientist, was born on March 14, 1879. And famed physicist Stephen Hawking died on March 14, 2018, at age 76. 

如果您仍然想知道为什么圆周率日对数学爱好者来说如此重要，这里还有两个原因：阿尔伯特·爱因斯坦，可能是世界上最著名的科学家，出生于 1879 年 3 月 14 日。著名物理学家斯蒂芬·霍金于 3 月 14 日去世 ，2018年，76岁。 

Although pi is not a perfect number. Hawking once had this to say: “One of the basic rules of the universe is that nothing is perfect. Perfection simply doesn’t exist. Without imperfection, neither you nor I would exist.” 

虽然 pi 不是一个完美数。 霍金曾经说过：“宇宙的基本规则之一就是没有什么是完美的。 完美根本不存在。 如果没有不完美，你和我都不会存在。”