万物简史 第78期:事物的测定(26)

 Delicacy was the key word. Not a whisper of disturbance¹ could be allowed into the room containing the apparatus², so Cavendish took up a position in an adjoining room and made his observations with a telescope aimed through a peephole. The work was incredibly exacting³ and involved seventeen delicate, interconnected measurements, which together took nearly a year to complete. When at last he had finished his calculations, Cavendish announced that the Earth weighed a little over six billion trillion metric tons, to use the modern measure. (A metric ton is 1,000 kilograms or 2,205 pounds.)精密是个关键词。设备所在的屋子里，容不得半点儿干扰。因此，卡文迪许就待在旁边的一间屋里，用望远镜瞄准一个窥孔来进行观察。这项工作是极其费劲的，要做17次精密而又互不关联的测量，他总共花了将近一年时间才完成。卡文迪许终于计算完毕，宣布地球的重量略略超过6 000 000 000 000 000 000 000吨（1吨约等于2205磅）。

Today, scientists have at their disposal machines so precise they can detect the weight of a single bacterium⁴ and so sensitive that readings can be disturbed by someone yawning seventy-five feet away, but they have not significantly improved on Cavendish's measurements of 1797. The current best estimate for Earth's weight is 5.9725 billion trillion metric tons, a difference of only about 1 percent from Cavendish's finding. Interestingly, all of this merely confirmed estimates made by Newton 110 years before Cavendish without any experimental evidence at all.

今天科学家手里的仪器，其精确度之高，可以测定一个细菌的重量；其灵敏度之高，有人在25米以外打个呵欠都会干扰读数。但是，他们对卡文迪许1797年的测量结果没有重大改动。目前对地球重量的最准确估计数是59725亿亿吨，与卡文迪许的结果只相差1％左右。有意思的是，这一切都只是证实了在卡文迪许110年之前牛顿的估计，而且没有迹象表明牛顿做过任何试验。

So, by the late eighteenth century scientists knew very precisely⁵ the shape and dimensions of the Earth and its distance from the Sun and planets; and now Cavendish, without even leaving home, had given them its weight. So you might think that determining the age of the Earth would be relatively⁶ straightforward⁷. After all, the necessary materials were literally⁸ at their feet. But no. Human beings would split the atom and invent television, nylon, and instant coffee before they could figure out the age of their own planet.

无论如何，到18世纪末，科学家们已经知道地球的确切形状和大小，以及地球到太阳和各个行星的距离。连足不出户的卡文迪许都已算出了它们的重量。于是，你或许会认为，确定地球的年龄会是一件相对容易的事。毕竟，他们实际上已经掌握一切必要的资料。然而，实际情形并非如此。人类要等到能够分裂原子、发明电视、尼龙和速溶咖啡以后，才算得出我们自己这颗行星的年龄。

To understand why, we must travel north to Scotland and begin with a brilliant and genial⁹ man, of whom few have ever heard, who had just invented a new science called geology.

若要知道其中的原因，我们必须北上去一趟苏格兰，先去拜访一位杰出而又可亲的人。这个人很少有人听说过，他刚刚发明了一门新学科：地质学。

 

1 disturbance   

n.动乱，骚动；打扰，干扰；(身心)失调

参考例句：

• He is suffering an emotional disturbance.他的情绪受到了困扰。
• You can work in here without any disturbance.在这儿你可不受任何干扰地工作。

2 apparatus   

n.装置，器械；器具，设备

参考例句：

• The school's audio apparatus includes films and records.学校的视听设备包括放映机和录音机。
• They had a very refined apparatus.他们有一套非常精良的设备。

3 exacting   

adj.苛求的，要求严格的

参考例句：

• He must remember the letters and symbols with exacting precision.他必须以严格的精度记住每个字母和符号。
• The public has been more exacting in its demands as time has passed.随着时间的推移，公众的要求更趋严格。

4 bacterium   

n.(pl.)bacteria 细菌

参考例句：

• The bacterium possibly goes in the human body by the mouth.细菌可能通过口进入人体。
• A bacterium is identified as the cause for his duodenal ulcer.一种细菌被断定为造成他十二指肠溃疡的根源。

5 precisely   

adv.恰好，正好，精确地，细致地

参考例句：

• It's precisely that sort of slick sales-talk that I mistrust.我不相信的正是那种油腔滑调的推销宣传。
• The man adjusted very precisely.那个人调得很准。

6 relatively   

adv.比较...地，相对地

参考例句：

• The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
• The operation was relatively painless.手术相对来说不痛。

7 straightforward   

adj.正直的，坦率的；易懂的，简单的

参考例句：

• A straightforward talk is better than a flowery speech.巧言不如直说。
• I must insist on your giving me a straightforward answer.我一定要你给我一个直截了当的回答。

8 literally   

adv.照字面意义，逐字地；确实

参考例句：

• He translated the passage literally.他逐字逐句地翻译这段文字。
• Sometimes she would not sit down till she was literally faint.有时候，她不走到真正要昏厥了，决不肯坐下来。

9 genial   

adj.亲切的，和蔼的，愉快的，脾气好的

参考例句：

• Orlando is a genial man.奥兰多是一位和蔼可亲的人。
• He was a warm-hearted friend and genial host.他是个热心的朋友，也是友善待客的主人。