大学英语精读听力第四册 unit3

[00:00.00]Unit Three Text
[00:22.65]Can you prove that the earth is round?
[00:25.31]Go ahead and try!
[00:27.19]Will you rely on your senses or will you have to draw on the opinions of experts?
[00:27.25]WHY DO WE BELIEVE THAT THE EARTH IS ROUND?     George Orwell
[00:32.29]Somewhere or other--I think it is in the preface to Saint Joan--
[00:37.36]Bernard Shaw remarks that we are more gullible and superstitious today
[00:41.80]than we were in the Middle Ages,
[00:43.44]and as an example of modern credulity
[00:46.18]he cites the widespread belief that the earth is round.
[00:49.87]The average man,says Shaw,
[00:52.32]can advance not a single reason for thinking that the earth is round.
[00:56.27]He merely swallows this theory because there is something about it
[01:00.45]that appeals to the twentieth-century mentality.
[01:03.43]Now,Shaw is exaggerating,but there is something in what he says,
[01:08.88]and the question is worth following up,
[01:10.92]for the sake of the light it throws on modern knowledge.
[01:14.03]Just why do we believe that the earth is round?
[01:17.32]I am not speaking of the few thousand astronomers,
[01:21.68]geographers and so forth who could give ocular proof,
[01:25.13]or have a theoretical knowledge of the proof,
[01:27.67]but of the ordinary newspaper-reading citizen,such as you or me.
[01:32.81]As for the Flat Earth theory, I believe I could refute it.
[01:36.68]If you stand by the seashore on a clear day,
[01:39.58]you can see the masts and funnels of invisible ships passing along the horizon.
[01:44.67]This phenomenon can only be explained by assuming that the earth's surface is curved.
[01:50.32]But it does not follow that the earth is spherical.
[01:53.89]Imagine another theory called the Oval Earth theory,
[01:52.89]which claims that the earth is shaped like an egg.
[01:55.74]What can I say against it?
[01:57.88]Against the Oval Earth man,
[01:56.88]the first card I can play is the analogy of the sun and moon.
[02:01.61]The Oval Earth man promptly answers that I don't know,
[02:05.19]by my own observation, that those bodies are spherical.
[02:09.13]I only know that they are round,
[02:11.51]and they may perfectly well be flat discs.
[02:14.67]I have no answer to that one.
[02:16.81]Besides,he goes on,
[02:18.46]what reason have I for thinking that the earth must be the same shape as the sun and moon?
[02:23.95]I can't answer that one either.
[02:26.35]My second card is the earth's shadow:
[02:29.75]when cast on the moon during eclipses,
[02:32.38]it appears to be the shadow of a round nobject.
[02:35.65]But how do I know, demands the Oval Earth man,
[02:39.12]that eclipses of the moon are caused by the shadow of the earth?
[02:42.88]The answer is that I don't know,
[02:45.47]but have taken this piece of information blindly from newspaper articles and science booklets
[02:51.92]Defeated in the minor exchanges,
[02:54.22]I now play my queen of trumps:
[02:54.29]the opinion of the experts.
[02:56.49]The Astronomer Royal, who ought to know, tells me that the earth is round.
[03:01.95]The Oval Earth man covers the queen with his king.
[03:00.95]Have I tested the Astronomer Royal's statement,
[03:04.19]and would I even know a way of testing it?
[03:06.67]Here I bring out my ace.
[03:08.55]Yes, I do know one test.
[03:10.74]The astronomers can foretell eclipses,
[03:13.43]and this suggests that their opinions about the solar system are pretty sound.
[03:18.29]I am,to my delight,
[03:20.07]justified in accepting their say-so about the shape of the earth.
[03:23.78]If the Oval Earth man answers--what I believe is true --
[03:28.06]that the ancient Egyptians, who thought the sun goes round the earth,
[03:31.93]could also predict eclipses,then bang goes my ace.
[03:36.47]I have only one card left:navigation.
[03:35.47]People can sail ships round the world,
[03:38.82]and reach the places they aim at,
[03:40.70]by calculations which assume that the earth is spherical.
[03:44.59]I believe that finishes the Oval Earth man,
[03:43.59]though even then he may possibly have some kind of counter.
[03:47.33]It'll be seen that my reasons for thinking that the earth is round are rather precarious ones
[03:46.33]Yet this is an exceptionally elementary piece of information.
[03:50.40]On most other questions I should have to fall back on the expert much earlier,
[03:55.23]and would be less able to test his pronouncements.
[03:58.29]And much the greater part of our knowledge is at this level.
[04:01.95]It does not rest on reasoning or on experiment,but on authority.
[04:06.70]And how can it be otherwise,
[04:08.71]when the range of knowledge is so vast that the expert himself
[04:12.42]is an ignoramus as soon as he strays away from his own specialty?
[04:17.05]Most people,if asked to prove that the earth is round,
[04:20.81]would not even bother to produce the rather weak arguments I have outlined above.
[04:25.35]They would start off by saying that "everyone knows" the earth to be round,
[04:30.29]and if pressed further, would become angry.
[04:30.34]In a way Shaw is right.
[04:33.01]This is a credulous age,
[04:34.34]and the burden of knowledge which we now have to carry is partly responsible.