万物简史 第352期:孤独的行星(17)

 　　The Moon's steady gravitational influence keeps the Earth spinning at the right speed and angle 由于月球持久的引力影响，地球能以合适的速度、合适的角度自转，

　　to provide the sort of stability necessary for the long and successful development of life. 为生命的长久和成功的发展提供一个必需的稳定环境。

　　This won't go on forever. 这种情况不会永远下去。

　　The Moon is slipping from our grasp at a rate of about 1.5 inches a year. 月球在以每年大约4厘米的速度脱离我们的控制。

　　In another two billion years it will have receded¹ so far that it won't keep us steady and we will have to come up with some other solution, 再过20亿年，它会退缩到很远的地方，无法再维持我们的稳定，我们不得不像个别的解决办法。

　　but in the meantime you should think of it as much more than just a pleasant feature in the night sky. 但是，与此同时，你该认识到，它远不只是夜空中一道悦目的风景线。

　　For a long time, astronomers² assumed that the Moon and Earth either formed together or that the Earth captured the Moon as it drifted by. 很久以来，天文学家一直有两种看法：一、月球和地球是同时形成的；二、是地球在月球飘过时把它抓住的。

　　We now believe, as you will recall from an earlier chapter, 我们在前面有一章已经谈到，现在我们认为，

　　that about 4.5 billion years ago a Mars-sized object slammed into Earth, blowing out enough material to create the Moon from the debris³. 大约44亿年以前，一个火星大小的物体撞击了地球，撞飞了足够的材料来形成月球。

　　This was obviously a very good thing for us—but especially so as it happened such a long time ago. 这对我们来说显然是一件好事情——尤其是因为这件事恰好发生在遥远的过去。

　　If it had happened in 1896 or last Wednesday clearly we wouldn't be nearly so pleased about it. 要是它发生在1896年或者上个星期三，我们肯定不会很高兴的。

　　Which brings us to our fourth and in many ways most crucial consideration: Timing⁴. 于是，我们就谈到第四个因素，在许多方面也是最重要的因素：合适的时间。

　　The universe is an amazingly fickle⁵ and eventful place, and our existence within it is a wonder. 宇宙是个变幻无常、变化多端的地方，我们在宇宙里的存在是个奇迹。

　　If a long and unimaginably complex sequence of events stretching back 4.6 billion years or so hadn't played out in a particular manner at particular times, 假如在过去的46亿年时间里发生的一长串极其复杂的事件没有在特定的时间以特定的方式告一段落，

　　if, to take just one obvious instance, the dinosaurs⁶ hadn't been wiped out by a meteor when they were, 举一个最明显的例子，假如恐龙当时不是因为一块陨石的撞击而灭绝，

　　you might well be six inches long, with whiskers and a tail, and reading this in a burrow⁷. 你很可能只有几厘米长，长着触角和尾巴，趴在哪个洞穴里看这本书。

1 receded   

v.逐渐远离( recede的过去式和过去分词 )；向后倾斜；自原处后退或避开别人的注视；尤指问题

参考例句：

• The floodwaters have now receded. 洪水现已消退。
• The sound of the truck receded into the distance. 卡车的声音渐渐在远处消失了。

2 astronomers   

n.天文学者，天文学家( astronomer的名词复数 )

参考例句：

• Astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自《简明英汉词典》
• Astronomers used to ask why only Saturn has rings. 天文学家们过去一直感到奇怪，为什么只有土星有光环。 来自《简明英汉词典》

3 debris   

n.瓦砾堆，废墟，碎片

参考例句：

• After the bombing there was a lot of debris everywhere.轰炸之后到处瓦砾成堆。
• Bacteria sticks to food debris in the teeth,causing decay.细菌附着在牙缝中的食物残渣上，导致蛀牙。

4 timing   

n.时间安排，时间选择

参考例句：

• The timing of the meeting is not convenient.会议的时间安排不合适。
• The timing of our statement is very opportune.我们发表声明选择的时机很恰当。

5 fickle   

adj.(爱情或友谊上)易变的，不坚定的

参考例句：

• Fluctuating prices usually base on a fickle public's demand.物价的波动往往是由于群众需求的不稳定而引起的。
• The weather is so fickle in summer.夏日的天气如此多变。

6 dinosaurs   

n.恐龙( dinosaur的名词复数 )；守旧落伍的人，过时落后的东西

参考例句：

• The brontosaurus was one of the largest of all dinosaurs. 雷龙是所有恐龙中最大的一种。 来自《简明英汉词典》
• Dinosaurs have been extinct for millions of years. 恐龙绝种已有几百万年了。 来自《简明英汉词典》

7 burrow   

vt.挖掘(洞穴)；钻进；vi.挖洞；翻寻；n.地洞

参考例句：

• Earthworms burrow deep into the subsoil.蚯蚓深深地钻进底土。
• The dog had chased a rabbit into its burrow.狗把兔子追进了洞穴。