[originaltext] Today most astronomers accept the notion that groups of stars

游客2023-08-28  24

问题  
Today most astronomers accept the notion that groups of stars that make up the universe are all moving farther and farther away from each other, but until very recently this idea of an expanding universe was not a theory most European scholars believed in since ancient times. And up to about the 17th century most of these scholars thought the size of the universe has remained unchanged since the moment of its creation or perhaps forever, with all the stars remaining more or less in place in relation to each other, but that was challenged in the late 17th century by Issac Newton’s idea of gravity as a force of attraction, which contradicted the idea of a universe that is static, unchanging. If gravity causes all the stars out there in space to attract each other as Newton said, then they couldn’t remain motionless. Sooner or later all the stars will fall in towards each other. Well, scientists then propose a new model. Taking Newton’s theory into account, they didn’t want to abandon the idea of motionless status, but for this model to work, they had to modify Newton’s law of gravity, so they theorized that for distance as large as those between stars, the gravitation force repels rather than attracts. As you might guess, there are other contradictions. But this is pretty resolved by the currently accepted theory, which says the universe is continuously expanding. You’ll be reading all about that as your homework tonight.
26. What does the speaker say about most astronomers today?
27. What did most European scholars believe about the size of the universe before 17th century?
28. What did some scientists try to explain by suggesting that stars repel each other?

选项 A、Why stars are moving farther apart.
B、Why stars attract each other.
C、Why stars don’t fall in towards each other.
D、Why stars remain motionless.

答案 C

解析 短文提到,根据牛顿的万有引力法则,星球迟早会与其他星球聚集。一些科学家提出了一个新的模式,他们不愿摒弃宇宙不运动的想法,因而不得不修改牛顿的万有引力法则。他们认为星球之间相互排斥而不是吸引。这么一来,他们需要对这一理论进行解释了。C为答案。
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