大学英语精读_第四册_Unit_Three.doc

Unit Three:Why Do We Believe That the Earth Is Round TextCan you prove that the earth is round? Go ahead and try! Will you rely on your senses or will you have to draw on the opinions of experts?WHY DO WE BELIEVE THAT THE EARTH IS ROUND? George OrwellSomewhere or other — I think it is in the preface to saint Joan — Bernard Shaw remarks that we are more gullible and superstitious today than we were in the Middle Ages, and as an example of modern credulity he cites the widespread belief that the earth is round. The average man, says Shaw, can advance not a single reason for thinking that the earth is round. He merely swallows this theory because there is something about it that appeals to the twentieth-century mentality.Now, Shaw is exaggerating, but there is something in what he says, and the question is worth following up, for the sake of the light it throws on modern knowledge. Just why do we believe that the earth is round? I am not speaking of the few thousand astronomers, geographers and so forth who could give ocular proof, or have a theoretical knowledge of the proof, but of the ordinary newspaper-reading citizen, such as you or me.As for the Flat Earth theory, I believe I could refute it. If you stand by the seashore on a clear day, you can see the masts and funnels of invisible ships passing along the horizon. This phenomenon can only be explained by assuming that the earths surface is curved. But it does not follow that the earth is spherical. Imagine another theory called the Oval Earth theory, which claims that the earth is shaped like an egg. What can I say against it?Against the Oval Earth man, the first card I can play is the analogy of the sun and moon. The Oval Earth man promptly answers that I dont know, by my own observation, that those bodies are spherical. I only know that they are round, and they may perfectly well be flat discs. I have no answer to that one. Besides, he goes on, what reason have I for thinking that the earth must be the