普通高中课程标准实验教科书 英语必修5 Unit 1 Great scientists（在线收听）

   Nicolaus Copernicus was frightened and his mind was confused. Although he had tried to ignore them, all his mathematical calculations led to the same conclusion: that the earth was not the centre of the solar system. Only if you put the sun there did the movements of the other planets in the sky make sense. Yet he could not tell anyone about his theory as the powerful Christian Church would have punished him for even suggesting such an idea. They believed God had made the world and for that reason the earth was special and must be the centre of the solar system.
The problem arose because astronomers had noticed that some planets in the sky seemed to stop, move backward and then go forward in a loop. Others appeared brighter at times and less bright at others. This was very strange if the earth was the centre of the solar system and all planets went round it.
        Copernicus had thought long and hard about these problems and tried to find an answer. He had collected observations of the stars and used all his mathematical knowledge to explain them. But only his new theory could do that. So between 1510 and 1514 he worked on it, gradually improving his theory until he felt it was complete.
         In 1514 he showed it privately to his friends. The changes he made to the old theory were revolutionary. He placed a fixed sun at the centre of the solar system with the planets going round it and only the moon still going round the earth. He also suggested that the earth was spinning as it went round the sun and this explained changes in the movement of the planets and in the brightness of the stars. His friends were enthusiastic and encouraged him to publish his ideas, but Copernicus was cautious. He did not want to be attacked by the Christian Church, so he only published it as he lay dying in 1543.
Certainly he was right to be careful. The Christian Church rejected his theory, saying it was against God's idea and people who supported it would be attacked. Yet Copernicus' theory is now the basis on which all our ideas of the universe are built. His theory replaced the Christian idea of gravity, which said things fell to earth because God created the earth as the centre of the universe. Copernicus showed this was obviously wrong. Now people can see that there is a direct link between his theory and the work of Isaac Newton, Albert Einstein and Stephen Hawking.