How taking a bath led to Archimedes' principle - Mark Salata

翻译人员: Minji Seo 校对人员: Claire Zhang

Some of the best opportunities to learn

一些学习的最好机会

are the moments in which we are perplexed.

是在我们觉得困惑的时刻。

Those moments in which you begin to wonder and question.

就是你开始疑惑及质疑的那些时刻。

These moments have happened throughout history.

这些时刻曾在历史上发生多次。

and have led to some truly amazing discoveries.

这些时刻也曾导致一些惊人的发现。

Take this story, for example.

举这个故事为例：

There once was a fellow named Archimedes.

曾经有个叫阿基米德的人。

He was born in 287 B.C. in the city of Syracuse in Sicily.

他于公元前287年，在西西里岛上的叙拉古城出生。

He was a Greek mathematician, physicist, engineer,

是古希腊的一名数学家、物理学家、工程师、

inventor, and astronomer.

发明家、及天文学家。

One day, Archimedes was summoned by the king of Sicily

有一天，西西里王宣召阿基米得

to investigate if he had been cheated by a goldsmith.

来调查金匠是否欺骗了他。

The king said he had given a goldsmith the exact amount of gold

国王说他已经给了金匠所需确切数量的金子

needed to make a crown.

来打造一顶皇冠。

However, when the crown was ready, the king suspected that the goldsmith cheated

但是，当皇冠完成时，国王怀疑这个金匠骗了他，

and slipped some silver into the crown,

在皇冠里掺了银，

keeping some of the gold for himself.

污了一些金子留给自己。

The king asked Archimedes to solve the problem.

国王要求阿基米得解决这个问题。

But there was a catch: he couldn't do any damage to the crown.

但有个前提：他不能破坏这顶皇冠。

One day, while taking his bath,

有一天，当阿基米得在洗澡的时候，

Archimedes noticed that the water level in the bathtub rose

他注意到当他浸到澡盆里时，

and overflowed as he immersed himself into the tub.

洗澡盆的水并上升及溢出。

He suddenly realized that how much water was displaced

他突然了解到水的排出量

depended on how much of his body was immersed.

跟他身体浸入多少有关。

This discovery excited him so much that he jumped out of the tub

这个发现使他非常兴奋。他甚至跳出澡盆，

and ran through the streets naked, shouting "Eureka!"

裸体跑到街上大喊 “Eureka!”

Which comes from the ancient Greek meaning "I found it."

即古希腊文 "我发现了" 的意思。

What did he find?

他发现了什么？

Well, he found a way to solve the king's problem.

他发现了解决国王的问题的方法。

You see, Archimedes needed to check the crown's density

就是，阿基米得需要查一下皇冠的密度

to see if it was the same as the density of pure gold.

看看它是否与纯金的密度相符

Density is a measure of an object's mass divided by its volume.

密度测量法是把物体质量除以体积

Pure gold is very dense, while silver is less dense.

纯金的密度非常高，而银的密度稍低

So if there was silver in the crown, it would be less dense than if it were made of pure gold.

所以如果皇冠里掺了银，其密度会比纯金打造的要低一些

But no matter what it was made of, the crown would be the same shape,

但不论此皇冠是什么做的，它的形状还是一样

which means the same volume.

也就是说体积相同

So if Archimedes could measure the mass of the crown first,

所以如果阿基米德先测量皇冠的质量

and then measure its volume,

再测量其体积

he could find out how dense it was.

他就可以找到其密度

But it is not easy to measure a crown's volume - it has an irregular shape,

但是要量皇冠的体积也不容易—— 它是不规则形状

that's different from a simple box or ball.

跟一个形状简单的盒子或球不一样

You can't measure its size and multiply like you might for other shapes.

你不能先测量尺寸然后乘起来， 像你量其他形状的东西一样，

The solution, Archimedes realized,

而其解决方法，阿基米得想到

was to give the crown a bath.

是让这个皇冠‘洗个澡’

by placing it in water and seeing how much water was displaced,

把它放在水里看它排出多少水量

he could measure the volume,

他可以测量水量

and he'd calculate the density of the crown.

然后他就能计算出这顶皇冠的密度

If the crown was less dense than pure gold,

如果这顶皇冠的密度小于纯金

then the goldsmith most definitely cheated the king.

那么这个金匠可断定是欺骗了国王

When Archimedes went back to the king and did his test,

当阿基米得回到国王面前做这项试验时

the story says, he found that the goldsmith had indeed cheated the king,

故事是这么说的，他发现这金匠的确骗了国王

and slipped some silver in. These days,

掺了一些银进去。

using the way an object displaces water to measure volume is called

现在使用物体的排水量来测体积被称为

Archimedes' principle. The next time you take a bath,

‘阿基米得原理’，所以下回你洗澡的时候

you can see Archimedes' principle in action,

你就可以观察到阿基米得原理的实际运用

and maybe you'll have a genius idea of your own.

说不定你还会发现一些天才点子呢！