万物简史 第53期:埃文斯牧师的宇宙(17)

 At this point, about 4.5 billion years ago, an object the size of Mars crashed into Earth, blowing out enough material to form a companion sphere, the Moon. Within weeks, it is thought, the flung material had reassembled itself into a single clump¹, and within a year it had formed into the spherical² rock that companions us yet. Most of the lunar material, it is thought, came from the Earth’s crust, not its core, which is why the Moon has so little iron while we have a lot. The theory, incidentally, is almost always presented as a recent one, but in fact it was first proposed in the 1940s by Reginald Daly of Harvard. The only recent thing about it is people paying any attention to it.

在这个时刻，大约在45亿年以前，一个火星大小的物体撞上了地球，炸飞了足够的材料来形成一颗伴星--月球。据认为，不出几个星期，被炸飞的材料已经重新聚成一团；不出一年，它变成了那个现在还陪伴着我们的岩石球体。据认为，构成月球的大部分材料来自地壳，不是地核，这就是月球上极少有铁的原因，而地球上铁却很多。顺便说一句，这个理论几乎总是被说成是最近提出的，而事实上，它最初由哈佛大学的雷金纳德?戴利于20世纪40年代提出。关于这个理论，惟一最近的事儿就是人们已经不大重视它了。

When Earth was only about a third of its eventual³ size, it was probably already beginning to form an atmosphere, mostly of carbon dioxide, nitrogen, methane⁴, and sulfur⁵. Hardly the sort of stuff that we would associate with life, and yet from this noxious⁶ stew⁷ life formed. Carbon dioxide is a powerful greenhouse gas. This was a good thing because the Sun was significantly dimmer back then. Had we not had the benefit of a greenhouse effect, the Earth might well have frozen over permanently⁸, and life might never have gotten a toehold. But somehow life did.

当地球还是它最终大小的大约三分之一的时候，它很可能已经开始形成大气，主要由二氧化碳、氮、甲烷和硫组成。我们几乎不会把这些东西与生命联系起来；然而，在这有毒的混杂物中，生命形成了。二氧化碳是一种强有力的温室气体。它是一样好东西，因为当时太阳已经弱多了。要是我们没有受益于温室效应，地球很可能已经永久被冰雪覆盖。生命也许永远找不到一块立足之地。但是，生命以某种方式出现了。

For the next 500 million years the young Earth continued to be pelted⁹ relentlessly¹⁰ by comets, meteorites¹¹, and other galactic debris¹², which brought water to fill the oceans and the components¹³ necessary for the successful formation of life. It was a singularly hostile environment and yet somehow life got going. Some tiny bag of chemicals twitched¹⁴ and became animate¹⁵. We were on our way.

在之后的5亿年里，年轻的地球继续受到彗星、陨石和银河系里其他碎块的无情撞击。这个过程产生了蓄满海洋的水，产生了成功形成生命所必不可少的成分。这是个极不友好的环境，然而生命还是以某种方式开始了。有一小袋化学物质抽动一下，变成了活的。我们快要来到这个世界上了。

Four billion years later people began to wonder how it had all happened. And it is there that our story next takes us.

40亿年以后，人们开始想，这一切到底是怎么发生的？下面，我们就来讲讲这个故事。

 

1 clump   

n.树丛，草丛；vi.用沉重的脚步行走

参考例句：

• A stream meandered gently through a clump of trees.一条小溪从树丛中蜿蜒穿过。
• It was as if he had hacked with his thick boots at a clump of bluebells.仿佛他用自己的厚靴子无情地践踏了一丛野风信子。

2 spherical   

adj.球形的；球面的

参考例句：

• The Earth is a nearly spherical planet.地球是一个近似球体的行星。
• Many engineers shy away from spherical projection methods.许多工程师对球面投影法有畏难情绪。

3 eventual   

adj.最后的，结局的，最终的

参考例句：

• Several schools face eventual closure.几所学校面临最终关闭。
• Both parties expressed optimism about an eventual solution.双方对问题的最终解决都表示乐观。

4 methane   

n.甲烷，沼气

参考例句：

• The blast was caused by pockets of methane gas that ignited.爆炸是由数袋甲烷气体着火引起的。
• Methane may have extraterrestrial significance.甲烷具有星际意义。

5 sulfur   

n.硫，硫磺（=sulphur）

参考例句：

• Sulfur emissions from steel mills become acid rain.炼钢厂排放出的硫形成了酸雨。
• Burning may produce sulfur oxides.燃烧可能会产生硫氧化物。

6 noxious   

adj.有害的，有毒的；使道德败坏的，讨厌的

参考例句：

• Heavy industry pollutes our rivers with noxious chemicals.重工业产生的有毒化学品会污染我们的河流。
• Many household products give off noxious fumes.很多家用产品散发有害气体。

7 stew   

n.炖汤，焖，烦恼；v.炖汤，焖，忧虑

参考例句：

• The stew must be boiled up before serving.炖肉必须煮熟才能上桌。
• There's no need to get in a stew.没有必要烦恼。

8 permanently   

adv.永恒地，永久地，固定不变地

参考例句：

• The accident left him permanently scarred.那次事故给他留下了永久的伤疤。
• The ship is now permanently moored on the Thames in London.该船现在永久地停泊在伦敦泰晤士河边。

9 pelted   

（连续地）投掷( pelt的过去式和过去分词 )； 连续抨击； 攻击； 剥去…的皮

参考例句：

• The children pelted him with snowballs. 孩子们向他投掷雪球。
• The rain pelted down. 天下着大雨。

10 relentlessly   

adv.不屈不挠地；残酷地；不间断

参考例句：

• The African sun beat relentlessly down on his aching head. 非洲的太阳无情地照射在他那发痛的头上。
• He pursued her relentlessly, refusing to take 'no' for an answer. 他锲而不舍地追求她，拒不接受“不”的回答。

11 meteorites   

n.陨星( meteorite的名词复数 )

参考例句：

• Small meteorites have left impact craters all over the planet's surface. 这个行星的表面布满了小块陨石留下的撞击坑。 来自《简明英汉词典》
• One theory about the existence of extraterrestrial life rests on the presence of carbon compounds in meteorites. 地球外存在生命的理论是基于陨星上存在碳化合物质这一事实的。 来自《简明英汉词典》

12 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。

13 components   

（机器、设备等的）构成要素，零件，成分； 成分( component的名词复数 )； [物理化学]组分； [数学]分量； （混合物的）组成部分

参考例句：

• the components of a machine 机器部件
• Our chemistry teacher often reduces a compound to its components in lab. 在实验室中化学老师常把化合物分解为各种成分。

14 twitched   

vt.& vi.（使）抽动，（使）颤动（twitch的过去式与过去分词形式）

参考例句：

• Her lips twitched with amusement. 她忍俊不禁地颤动着嘴唇。
• The child's mouth twitched as if she were about to cry. 这小孩的嘴抽动着，像是要哭。 来自《简明英汉词典》

15 animate   

v.赋于生命，鼓励；adj.有生命的，有生气的

参考例句：

• We are animate beings,living creatures.我们是有生命的存在，有生命的动物。
• The girls watched,little teasing smiles animating their faces.女孩们注视着，脸上挂着调皮的微笑，显得愈加活泼。