时差N小时:圆周率的奥妙

00:00

00:00

MP3下载 文本下载

https://online2.tingclass.net/lesson/shi0529/0009/9697/6.mp3

https://image.tingclass.net/statics/js/2012

Y: Don. Don?

D: What?

Y: What are you doing?

D: I was trying to break the record for memorizingpi. Now I'll have to start over.

Y: Memorize pi? Oh yeah, I remember that from 7th grade geometry. But how can youmemorize pi? We usually abbreviate it as 3.14, but the numbers just keep going after thedecimal point.

D: I'm trying to memorize as many numbers as I can. The record is 42,000 decimal places.

Y: Wow. You're really going to try to memorize that much? Why? What is pi, anyway.

D: It's only one of the most fascinating numbers in the history of mathematics. It soundssimple: Pi equals the circumference of a circle divided by its diameter. No matter how largeor small the circle, the ratio always equals pi.

Y: That's interesting.

D: Yes, and it has been for over 4000 years. The Babylonians were the first to approximate pi,and ever since, mathematicians have come up with ways of figuring it more accurately. Inmodern times we've used supercomputers to calculate pi to billions of decimal places.

Y: That's really something. But what's all the excitement about? I mean, what is pi used for?

D: It's used to measure the length of arcs and other curves and to determine the area ofsectors and other curves. It's also used to measure the volume of solids. For instance, if you'rea rocket scientist trying to calculate the fuel capacity of a cylindrical fuel tank, pi's your guy.

Y: Cool.

D: Now, if you'll excuse me, I've got a record to break.

Y: Good luck.

D: 3.1415 9265 3589 7932 3846 . . .

【生词注释】

memorize v.记住, 记下

pi n.圆周率

start over 重新开始

geometry n. 几何学

decimal point 小数点

fascinating adj.迷人的

curve n.曲线

sector n.扇形

D: 3.1415926535 . . .

Y: Don. Don?

D: 什么事?

Y: 你在干吗?

D: 我正努力背圆周率来打破纪录。现在我必须重新开始。

Y: 背圆周率?我记得在7年级学几何时背的。你是如何背的?我们通常缩进至3.14，但是小数点后还有很多数。

D: 我正努力尽量多背些。纪录是背到小数点后第42,000位。

Y: 你真准备背那么多?为什么?到底什么是圆周率。

D: 圆周率是数学史上最吸引人的数字。它听起来很简单，圆的直径除以周长就等于圆周率。无论圆多大或多小，结果都是一样的。

Y: 很有意思。

D: 圆周率已经有4千年历史了啦。巴比伦人首个得到的数字接近圆周率，从那以后，数学家用各种方法来准确计算。现在我们用超级计算机来计算元中旅到小数点上亿后。

Y: 真有意思。有什么值得高兴的?圆周率用来干什么?

D:用来计算弓形和各种曲线的长度来决定扇形的面试和其他曲线。圆周率也用来测量固体的体积。比如，如果你是火箭专家，正准备计算圆柱形燃料容器的燃料体积，就得用到圆周率。

D: 酷。

Y：打不起，我得准备打破记录了。

D: 好运。

Y：3.1415 9265 3589 7932 3846 . . .