万物简史 第363期:进入对流层(4)

 　　Even so, spaceships have to take care in the outer atmosphere, particularly on return trips to Earth, 即使这样，宇宙飞船在外层大气也不得不小心翼翼，尤其是在重返地球的过程中。

　　as the space shuttle Columbia demonstrated all too tragically¹ in February 2003. 2003年2月发生的“哥伦比亚”号航天飞机的悲剧就说明了这一点。

　　Although the atmosphere is very thin, if a craft comes in at too steep an angle—more than about 6 degrees, or too swiftly 虽然大气很薄，但要是飞船进入大气层的角度太大——大约6度以上，或者速度太快，

　　it can strike enough molecules² to generate drag of an exceedingly combustible³ nature. 它就会撞击大量分子，产生极易引起燃烧的拉力。

　　Conversely, if an incoming vehicle hit the thermosphere at too shallow an angle, 反之，如果返程的飞行器进入大气层的角度太小，

　　it could well bounce back into space, like a pebble⁴ skipped across water. 它很可能会弹回空间，就像掠过水面的卵石那样。

　　But you needn't venture to the edge of the atmosphere to be reminded of what hopelessly ground-hugging beings we are. 若要知道自己是如何离不开地面，你不必冒险去大气层的边缘，

　　As anyone who has spent time in a lofty city will know, 在任何地势很高的城市里生活过的人都会知道，

　　you don't have to rise too many thousands of feet from sea level before your body begins to protest. 你无须登上海拔几百米的高处，你的身体就会开始觉得不舒服。

　　Even experienced mountaineers, with the benefits of fitness, training, and bottled oxygen, quickly become vulnerable at height to confusion, 即使是有经验的登山运动员，虽然他们身体健壮、受过训练、带着氧气瓶，也很快会有高原反应：

　　nausea⁵, exhaustion⁶, frostbite, hypothermia, migraine, loss of appetite, and a great many other stumbling dysfunctions. 头脑不清呀，恶心呀，疲劳呀，冻伤呀，体温过低呀，没有胃口呀，以及许多别的机能障碍。

　　In a hundred emphatic⁷ ways the human body reminds its owner that it wasn't designed to operate so far above sea level. 人体会以各种强有力的方式提醒它的主人，它不适于在海拔太高的地方运转。

　　Even under the most favorable circumstances, the climber Peter Habeler has written of conditions atop Everest, “即使在最有利的情况下，”登山运动员彼得·晗伯勒在写到珠穆朗玛峰顶上的情况时说，

　　"every step at that altitude demands a colossal⁸ effort of will. “在那个高度，每走一步都需要极大的意志力。

　　You must force yourself to make every movement, reach for every handhold. 你必须强迫自己往前走，抓住能抓住的地方。

　　You are perpetually threatened by a leaden, deadly fatigue⁹." 你永远有一种极度的按劳感。”

1 tragically   

adv. 悲剧地，悲惨地

参考例句：

• Their daughter was tragically killed in a road accident. 他们的女儿不幸死于车祸。
• Her father died tragically in a car crash. 她父亲在一场车祸中惨死。

2 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

3 combustible   

a. 易燃的,可燃的; n. 易燃物,可燃物

参考例句：

• Don't smoke near combustible materials. 别在易燃的材料附近吸烟。
• We mustn't take combustible goods aboard. 我们不可带易燃品上车。

4 pebble   

n.卵石，小圆石

参考例句：

• The bird mistook the pebble for egg and tried to hatch it.这只鸟错把卵石当蛋，想去孵它。
• The pebble made a ripple on the surface of the lake.石子在湖面上激起一个涟漪。

5 nausea   

n.作呕，恶心；极端的憎恶(或厌恶)

参考例句：

• Early pregnancy is often accompanied by nausea.怀孕期常有恶心的现象。
• He experienced nausea after eating octopus.吃了章鱼后他感到恶心。

6 exhaustion   

n.耗尽枯竭，疲惫，筋疲力尽，竭尽，详尽无遗的论述

参考例句：

• She slept the sleep of exhaustion.她因疲劳而酣睡。
• His exhaustion was obvious when he fell asleep standing.他站着睡着了，显然是太累了。

7 emphatic   

adj.强调的，着重的；无可置疑的，明显的

参考例句：

• Their reply was too emphatic for anyone to doubt them.他们的回答很坚决，不容有任何人怀疑。
• He was emphatic about the importance of being punctual.他强调严守时间的重要性。

8 colossal   

adj.异常的，庞大的

参考例句：

• There has been a colossal waste of public money.一直存在巨大的公款浪费。
• Some of the tall buildings in that city are colossal.那座城市里的一些高层建筑很庞大。

9 fatigue   

n.疲劳，劳累

参考例句：

• The old lady can't bear the fatigue of a long journey.这位老妇人不能忍受长途旅行的疲劳。
• I have got over my weakness and fatigue.我已从虚弱和疲劳中恢复过来了。