【词汇】雅思阅读常用词(025)- Let’s Go Bats

Cambridge 07 Test 1 – Passage1: Let’s Go Bats

Bats have a problem: how to find their way around in the dark. They hunt at night, and cannot use light to help them find prey and avoid obstacles. You might say that this is a problem of their own making, one that they could avoid simply by changing their habits and hunting by day. But the daytime economy is already heavily exploited by other creatures such as birds. Given that there is a living to be made at night, and given that alternative daytime trades are thoroughly occupied, natural selection has favoured bats that make a go of the night-hunting trade. It is probable that the nocturnal trades go way back in the ancestry of all mammals. In the time when the dinosaurs dominated the daytime economy, our mammalian ancestors probably only managed to survive at all because they found ways of scraping a living at night. Only after the mysterious mass extinction of the dinosaurs about 65 million years ago were our ancestors able to emerge into the daylight in any substantial numbers.

  • prey 英 [preɪ] 美 [pre] n. 捕食;牺牲者;被捕食的动物

  • obstacle 英 [‘ɒbstək(ə)l] 美 [‘ɑbstəkl] n. 障碍,干扰;妨害物

  • exploit 英 [ˈeksplɔɪt;ɪkˈsplɔɪt] 美 [ɛksplɔɪt; ɪkˈsplɔɪt] vt. 开发,开拓;剥削;开采

  • alternative 英 [ɔːl’tɜːnətɪv; ɒl-] 美 [ɔl’tɝnətɪv] n. 二中择一;供替代的选择 adj. 供选择的;选择性的;交替的

  • nocturnal 英 [nɒk’tɜːn(ə)l] 美 [nɑk’tɝnl] adj. 夜的;夜曲的;夜间发生的

  • ancestry 英 [‘ænsestrɪ] 美 [‘ænsɛstri] n. 祖先;血统

  • mammal 英 [‘mæm(ə)l] 美 [‘mæml] n. [脊椎] 哺乳动物

  • scrape 英 [skreɪp] 美 [skrep] vi. 刮掉;刮出刺耳声

  • extinction 英 [ɪk’stɪŋ(k)ʃ(ə)n; ek-] 美 [ɪk’stɪŋkʃən] n. 灭绝;消失;消灭;废止

Bats have an engineering problem: how to find their way and find their prey in the absence of light. Bats are not the only creatures to face this difficulty today. Obviously the night-flying insects that they prey on must find their way about somehow. Deep-sea fish and whales have little or no light by day or by night. Fish and dolphins that live in extremely muddy water cannot see because, although there is light, it is obstructed and scattered by the dirt in the water. Plenty of other modern animals make their living in conditions where seeing is difficult or impossible.

Given the questions of how to manoeuvre in the dark, what solutions might an engineer consider? The first one that might occur to him is to manufacture light, to use a lantern or a searchlight. Fireflies and some fish (usually with the help of bacteria) have the power to manufacture their own light, but the process seems to consume a large amount of energy. Fireflies use their light for attracting mates. This doesn’t require a prohibitive amount of energy: a male’s tiny pinprick of light can be seen by a female from some distance on a dark night, since her eyes are exposed directly to the light source itself. However, using light to find one’s own way around requires vastly more energy, since the eyes have to detect the tiny fraction of the light that bounces off each part of the scene. The light source must therefore be immensely brighter if it is to be used as a headlight to illuminate the path, than if it is to be used as a signal to others. In any event, whether or not the reason is the energy expense, it seems to be the case that, with the possible exception of some weird deep-sea fish, no animal apart from man uses manufactured light to find its way about.

  • obstruct 英 [əb’strʌkt] 美 [əb’strʌkt] vt. 妨碍;阻塞;遮断 vi. 阻塞;设障碍

  • scatter 英 [‘skætə] 美 [‘skætɚ] vt. 使散射;使散开,使分散

  • manoeuvre 英 [mə’nuːvə] 美 [mə’nu:və] n. 策略(等于maneuvre) vt. 诱使;操纵;耍花招 vi. 调动;演习;用策略

  • lantern 英 [‘læntən] 美 [‘læntɚn] n. 灯笼;提灯;灯笼式天窗

  • bacteria 英 [bæk’tɪərɪə] 美 [bæk’tɪrɪə] n. [微] 细菌

  • prohibitive 英 [prə(ʊ)’hɪbɪtɪv] 美 [prə’hɪbətɪv] adj. 禁止的,禁止性的;抑制的;(费用,价格等)过高的;类同禁止的

  • pinprick 英 [‘pɪnprɪk] 美 [‘pɪnprɪk] n. 针刺;针孔;令人烦恼的小事

  • fraction 英 [‘frækʃ(ə)n] 美 [‘frækʃən] n. 分数;部分;小部分;稍微

  • bounce 英 [baʊns] 美 [baʊns] vi. 弹跳;弹起,反跳;弹回

  • immensely 英 [ɪ’menslɪ] 美 [i’mensli] adv. 极大地;无限地;广大地;庞大地

  • illuminate 英 [ɪ’l(j)uːmɪneɪt] 美 [ɪ’lumɪnet] vt. 阐明,说明;照亮;使灿烂;用灯装饰

  • expense 英 [ɪk’spens; ek-] 美 [ɪk’spɛns] n. 损失,代价;消费;开支

What else might the engineer think of? well, blind humans sometimes seem to have an uncanny sense of obstacles in their path. It has been given the name ‘facial vision’, because blind people have reported that it feels a bit like the sense of touch, on the face. One report tells of a totally blind boy who could ride his tricycle at good speed round the block near his home, using facial vision. Experiments showed that, in fact, facial vision is nothing to do with touch or the front of the face, although the sensation may be referred to the front of the face, like the referred pain in a phantom limb. The sensation of facial vision, it turns out, really goes in through the ears. Blind people, without even being aware of the fact, are actually using echoes of their own footsteps and of other sounds, to sense the presence of obstacles. Before this was discovered, engineers had already built instruments to exploit the principle, for example to measure the depth of the sea under a ship. After this technique had been invented, it was only a matter of time before weapons designers adapted it for the detection of submarines. Both sides in the Second world war relied heavily on these devices, under such codenames as Asdic (British) and Sonar (American), as well as Radar (American) or RDF (British), which uses radio echoes rather than sound echoes.

The Sonar and Radar pioneers didn’t know it then, but all the world now knows that bats, or rather natural selection working on bats, had perfected the system tens of millions of years earlier, and their ‘radar’ achieves feats of detection and navigation that would strike an engineer dumb with admiration. It is technically incorrect to talk about bat ‘radar’, since they do not use radio waves. It is sonar. But the underlying mathematical theories of radar and sonar are very similar, and much of our scientific understanding of the details of what bats are doing has come from applying radar theory to them. The American zoologist Donald Griffin, who was largely responsible for the discovery of sonar in bats, coined the term ‘echolocation’ to cover both sonar and radar, whether used by animals or by human instruments.

  • uncanny 英 [ʌn’kænɪ] 美 [ʌn’kæni] adj. 神秘的;离奇的;可怕的

  • sensation 英 [sen’seɪʃ(ə)n] 美 [sɛn’seʃən] n. 感觉;轰动;感动

  • refer 英 [rɪ’fɜː] 美 [rɪ’fɝ] vt. 涉及;委托;归诸于;使…求助于 vi. 参考;涉及;提到;查阅

  • phantom 英 [‘fæntəm] 美 [‘fæntəm] n. 幽灵;幻影;虚位 adj. 幽灵的;幻觉的;有名无实的

  • sonar 英 [‘səʊnɑː] 美 [‘sonɑr] n. 声纳;声波定位仪(等于asdic)

  • radar 英 [‘reɪdɑː] 美 [‘redɑr] n. [雷达] 雷达,无线电探测器

  • feat 英 [fiːt] 美 [fit] n. 功绩,壮举;技艺表演 adj. 合适的;灵巧的

  • coin 英 [kɒɪn] 美 [kɔɪn] n. 硬币,钱币 vt. 铸造(货币);杜撰,创造






工程师们还能想到什么呢?比如盲人,他们好像对路上的障碍有着不可思议的直觉。人们把这叫做“面感视觉”,因为据盲人说感觉到有障碍物的时候就像脸部被触摸一样。一则报道称一位完全失明的男孩能凭借面感视觉绕着附近街区快速骑三轮车。实验表明面感视觉实际上与“感”和“面”没有任何关系,尽管这种感觉可能被认为源自面部正前方,正如幻肢中的牵涉性痛感一样。事实上,面感视觉是通过耳朵传输的。尽管盲人并没有意识到这一点,但实际生活中他们的确在运用自己的步伐以及其他声音的回声来感觉路上障碍物的存在。在这个事实没有被发现之前,其实工程师们已经利用这条原理制造了很多设备。比如用回声来测量船底海洋的深度。在这项技术发明之后,武器制造者很快就将其改良来侦测潜水艇。二战期间,交战双方都充分运用了这些设备,代号分别是英国的Asdic和美国Sonar以及美国的Radar或是英国的 RDF,后两者使用了雷达回声技术而非声波回声技术。

当时的雷达声呐技术先驱们毫不知情,但现在所有人都明白了正是蝙蝠,或者说是自然选择在蝙蝠身上的鬼斧神工,早在几百万年前就已经使这种技术达到完美境界,而蝙蛹的“雷达”在探测及导航方面取得的完美成果足以让人类工程师佩服到哑口无言。从技术角度讲,说蝙蝠有雷达功能是不准确的,因为它们并没有运用无线电波,而只是运用声呐系统。但实际上雷达和声呐的基本原理是非常相似的,而且大多数关于蝙蝠行为细节的科学理解都是利用雷达理论完成的。美国动物学家Donald Griffin教授第一个发现蝙蝠利用声呐技术,由此,他创造出了一个新的词汇:回声定位。这个词涵盖了动物和人类所利用的雷达及声呐系统。