Lesson 42 Recording an earthquake

歌曲 Lesson 42 Recording an earthquake
歌手 英语听力
专辑 新概念英语(第四册)

歌词

[00:01.47] Lesson 42
[00:03.45] Recording an earthquake
[00:11.47] What does a pen have to do to record on paper the vibrations generated by an earthquake?
[00:19.70] An earthquake comes like a thief in the night, without warning.
[00:24.83] It was necessary, therefore, to invent instruments that neither slumbered nor slept.
[00:31.38] Some devices were quite simple.
[00:33.83] One, for instance, consisted of rods of various lengths and thicknesses which would stand up on end like ninepins.
[00:41.76] When a shock came, it shook the rigid table upon which these stood.
[00:47.32] If it were gentle, only the more unstable rods fell.
[00:51.64] If it were severe, they all fell.
[00:54.65] Thus the rods, by falling, and by the direction in which they fell,
[00:59.67] recorded for the slumbering scientist the strength of a shock that was too weak to waken him,
[01:05.62] and the direction from which it came.
[01:09.39] But instruments far more delicate than that were needed if any really serious advance was to be made.
[01:17.67] The ideal to be aimed at was to devise an instrument that could record with a pen on paper,
[01:24.33] the movements of the ground or of the table as the quake passed by.
[01:29.99] While I write my pen moves, but the paper keeps still.
[01:35.03] With practice, no doubt, I could in time learn to write by holding the pen still while the paper moved.
[01:42.15] That sounds a silly suggestion,
[01:44.45] but that was precisely the idea adopted in some of the early instruments (seismometers) for recording earthquake waves.
[01:54.25] But when table, penholder and paper are all moving, how is it possible to write legibly?
[02:02.40] The key to a solution of that problem lay in an everyday observation.
[02:07.97] Why does a person standing in a bus or train tend to fall when a sudden start is made?
[02:15.73] It is because his feet move on, but his head stays still.
[02:21.17] A simple experiment will help us a little further.
[02:25.02] Tie a heavy weight at the end of a long piece of string.
[02:29.53] With the hand held high in the air, hold the string so that the weight nearly touches the ground.
[02:36.32] Now move the hand to and fro and around but not up and down.
[02:41.93] It will be found that the weight moves but slightly or not at all.
[02:47.50] Imagine a pen attached to the weight in such a way that its point rests upon a piece of paper on the floor.
[02:56.08] Imagine an earthquake shock shaking the floor, the paper, you and your hand.
[03:02.96] In the midst of all this movement, the weight and the pen would be still.
[03:08.48] But as the paper moved from side to side under the pen point, its movement would be recorded in ink upon its surface.
[03:16.83] It was upon this principle that the first instruments were made, but the paper was wrapped round a drum which rotated slowly.
[03:25.96] As long as all was still, the pen drew a straight line,
[03:30.63] but while the drum was being shaken, the line that the pen was drawing wriggled from side to side.
[03:38.00] The apparatus thus described, however,
[03:40.25] records only the horizontal component of the wave movement, which is, in fact, much more complicated.
[03:48.12] If we could actually see the path described by a particle,
[03:51.63] such as a sand grain in the rock,
[03:54.41] it would be more like that of a bluebottle buzzing round the room; it would be up and down, to and fro and from side to side.
[04:04.45] Instruments have been devised and can be so placed that all three elements can be recorded in different graphs.
[04:13.37] When the instrument is situated at more than 700 miles from the earthquake centre,
[04:18.83] the graphic record shows three waves arriving one after the other at short intervals.
[04:25.57] The first records the arrival of longitudinal vibrations.
[04:30.84] The second marks the arrival of transverse vibrations which travel more slowly and arrive several minutes after the first.
[04:39.70] These two have travelled through the earth.

歌词大意

[00:01.47] dì 42 kè
[00:03.45] jì lù dì zhèn
[00:11.47] zài zhǐ shàng jì lù dì zhèn suǒ yǐn qǐ de zhèn dòng shí, gāng bǐ xū yào zuò shí mǒ?
[00:19.70] dì zhèn jiù xiàng yè jiān de xiǎo tōu, bù dǎ zhāo hū jiù lái le.
[00:24.83] yīn cǐ, yǒu bì yào fā míng yī zhǒng yí qì, jì bù dǎ dǔn, yě bù shuì jiào.
[00:31.38] yǒu xiē zhuāng zhì fēi cháng jiǎn dān.
[00:33.83] lì rú, yǒu yī zhǒng zhuāng zhì shì yóu yī xiē cháng duǎn cū xì bù tóng de mù bàng zǔ chéng, jiù xiàng jiǔ zhù xì de mù bàng yí yàng shù lì zhe.
[00:41.76] yī dàn yǒu dì zhèn, jiù huì zhèn dòng shù lì zài jiān yìng zhuō zi shàng de mù bàng.
[00:47.32] rú guǒ dì zhèn qīng wēi, zhǐ yǒu bù wěn dìng de mù bàng dǎo xià.
[00:51.64] rú guǒ dì zhèn jù liè, suǒ yǒu de mù bàng dōu huì dǎo xià.
[00:54.65] yīn cǐ, tōng guò qí dǎo xià de fāng xiàng,
[00:59.67] zài dì zhèn de qiáng dù tài ruò bù zú yǐ jīng xǐng shú shuì zhōng de kē xué jiā de shí hòu,
[01:05.62] zhèi xiē mù bàng jì lù le dì zhèn fā shēng de fāng xiàng.
[01:09.39] dàn shì, rú guǒ yào qǔ de zhēn zhèng de zhòng dà jìn zhǎn, xū yào bǐ zhè zhǒng zhuāng zhì jīng xì dé duō de yí qì.
[01:17.67] lǐ xiǎng de mù biāo shì shè jì chū zhè yàng yī zhǒng yí qì:
[01:24.33] dāng dì zhèn fā shēng shí, tā néng yòng bǐ zài zhǐ shàng jì lù xià dà dì hé zhuō zi de yùn dòng qíng kuàng.
[01:29.99] dāng wǒ xiě zì shí, bǐ shì yí dòng de, zhǐ shì jìng zhǐ de.
[01:35.03] háo wú yí wèn, tōng guò xùn liàn, wǒ zuì zhōng néng xué huì zài bǐ bù dòng ér zhǐ yí dòng de qíng kuàng xià xiě zì.
[01:42.15] zhè tīng qǐ lái sì hū shì yī zhǒng yú chǔn de xiǎng fǎ,
[01:44.45] dàn shì zǎo qī jì lù dì zhèn bō de yí qì cè zhèn yí zhèng shì cǎi yòng le zhè zhǒng sī lù.
[01:54.25] kě shì, dāng zhuō zi bǐ gǎn zhǐ dōu zài yí dòng shí, zěn me néng shū xiě de qīng chǔ ne?
[02:02.40] kě yǐ cóng wǒ men de rì cháng shēng huó guān chá zhōng zhǎo dào zhè gè wèn tí de dá àn.
[02:07.97] dāng chē tū rán kāi dòng shí, zhàn zài gōng gòng qì chē huò huǒ chē shàng de rén wéi shén me huì yǒu yào shuāi dǎo de qīng xiàng ne?
[02:15.73] zhè shì yīn wèi tā de jiǎo dòng le, ér tā de tóu bǎo chí zhe jìng zhǐ.
[02:21.17] yí gè jiǎn dān de shí yàn kě yǐ bāng zhù wǒ men jìn yī bù lǐ jiě zhè gè wèn tí.
[02:25.02] bǎ yí gè zhòng wù shuān zài yī gēn zhǎng shéng zi de yī duān,
[02:29.53] bǎ shǒu gāo jǔ zài kōng zhōng wò zhù shéng zi, shǐ zhòng wù jī hū jiē chù dì miàn.
[02:36.32] xiàn zài bǎ shǒu lái huí yǐ jí xuán zhuǎn bǎi dòng, dàn bú yào shàng xià bǎi dòng,
[02:41.93] jié guǒ huì fā xiàn, zhòng wù yùn dòng de fú dù hěn xiǎo, shèn zhì gēn běn méi dòng.
[02:47.50] jiǎ dìng àn zhào zhè yàng yī zhǒng fāng shì bǎ bǐ shuān zài zhòng wù shàng, shǐ bǐ jiān xuán tíng zài dì bǎn shàng yī zhāng zhǐ shàng fāng.
[02:56.08] jiǎ dìng dì zhèn fā shēng le, dì bǎn zhǐ nǐ hé nǐ de shǒu dōu huì fā shēng zhèn dòng,
[03:02.96] zài zhèi xiē yùn dòng fā shēng shí, zhòng wù hé bǐ bǎo chí jìng zhǐ.
[03:08.48] dàn shì yóu yú bǐ jiān xià fāng de zhǐ zhāng zuò wǎng fù yùn dòng, qí yùn dòng qíng kuàng jiù huì bèi mò shuǐ jì lù zài zhǐ zhāng shàng.
[03:16.83] gēn jù zhè yī yuán lǐ, zhì zào chū le zuì chū de dì zhèn yí qì, dàn shì zhǐ zhāng shì juǎn zài huǎn màn xuán zhuǎn de yuán tǒng shàng de.
[03:25.96] zhǐ yào yī qiè dōu shì jìng zhǐ de, bǐ jiù huì huà yī tiáo zhí xiàn
[03:30.63] dàn shì dāng yuán tǒng shòu dào zhèn dòng shí, bǐ suǒ huà chū lái de xiàn jiù huì zuǒ yòu bǎi dòng.
[03:38.00] rán ér, zhè lǐ suǒ miáo shù de zhè zhǒng yí qì,
[03:40.25] jì lù xià lái de zhǐ shì dì zhèn bō de shuǐ píng fèn liàng, dì zhèn bō de yùn dòng shí jì bǐ zhè yào fù zá dé duō.
[03:48.12] jiǎ rú wǒ men zhēn néng kàn dào suǒ miáo shù de yí gè lì zǐ de yùn dòng guǐ jī,
[03:51.63] bǐ fāng shuō yán shí zhōng de shā lì,
[03:54.41] qí yùn dòng guǐ jī jiù xiàng yì zhī wēng wēng jiào de lǜ tóu cāng yíng zài wū nèi de fēi xíng guǐ jī, chéng xiàn chū shàng shàng xià xià lái lái huí huí zuǒ zuǒ yòu yòu sān zhǒng yùn dòng xíng shì.
[04:04.45] yǐ jīng shè jì chū le yī xiē yí qì, bǎ tā men àn zhào yí dìng de fāng shì ān fàng jiù kě yǐ jì lù xià zhè sān zhǒng yùn dòng xíng shì de qū xiàn tú.
[04:13.37] rú guǒ bǎ zhè zhǒng yí qì ān fàng zài jù lí zhèn zhōng 700 duō yīng lǐ yuǎn de dì fāng,
[04:18.83] qí jì lù de qū xiàn biǎo míng, zhè sān zhǒng xíng shì de bō huì zài bǐ jiào duǎn de shí jiān jiàn gé nèi xiān hòu dào dá.
[04:25.57] shǒu xiān jì lù xià lái de zòng xiàng bō de dào dá.
[04:30.84] rán hòu jì lù xià lái de shì héng xiàng bō de dá dào, héng xiàng bō bǐ zòng xiàng bō chuán bō dé màn, zài zòng xiàng bō dào dá jǐ fēn zhōng hòu cái néng dào dá.
[04:39.70] zhè liǎng zhǒng bō dōu shì chuān guò dì qiú ér lái de.