The Center of the Universe|宇宙的中心

by William Ryan

What are black holes, and how do they form?

　　Contrary to what the term black hole seems to imply, black holes are not empty space. As a matter of fact, they are a _(1)_ amount of matter packed into a relatively tiny space. The result is a gravitational field so powerful that nothing, not even light, can _(2)_ its pull. If you can imagine a star 10 times larger than the sun squeezed into a sphere approximately the _(3)_ of New York City, you will understand the concept. Princeton University physicist John Wheeler _(4)_ the term in 1967, but black holes were considered just an abstract, mathematical idea at first. Even though their _(5)_ was predicted by Albert Einstein's theory of relativity, the genius himself thought they only existed in theory. Then in 1931, Nobel Prize-winning astronomer Subrahmanyan Chandrasekhar calculated that certain high-mass stars could actually collapse into black holes, and he turned _(6)_ to be right. Astronomers have subsequently found many examples of the phenomenon.

　　When a massive star dies, it leaves a small, dense core. If the mass of this core is more than approximately three times the mass of the sun, then the force of gravity overwhelms all other forces and produces a black hole. Most black holes are 10 to 24 times more massive than the sun. There are also supermassive black holes that are millions of times as large as the sun. Scientists believe that these _(7)_ giants lie at the center of all large galaxies, including the Milky Way.

1. (A) barbarian (B) descriptive (C) tremendous (D) sentimental

2. (A) shatter (B) corrupt (C) resist (D) disgrace

3. (A) size (B) number (C) depth (D) code

4. (A) compensated (B) coined (C) dedicated (D) exploited

5. (A) existence (B) endurance (C) fidelity (D) nomination

6. (A) over (B) down (C) away (D) out

7. (A) mediocre (B) mysterious (C) indifferent (D) applicable

 

宇宙的中心

什么是黑洞，而它们又是如何形成的呢？

　　与黑洞这个专有名词字面意义相反的是，它并非空洞的空间。事实上，黑洞是质量相当大的物质被塞进一个相当狭小的空间。其结果会产生一个相当强大的重力场，以致任何物质甚至光线都无法抵抗其拉力。如果你能够想象一颗比太阳还要大上十倍的恒星被硬塞进一个大约只有纽约市大小的球体中，你就会了解这个概念了。普林斯顿大学的物理学家约翰．惠勒在 1967 年创造了黑洞这个名词，但最初黑洞仅被视为一种抽象的数学概念。即使在艾伯特．爱因斯坦的相对论中已预测到黑洞的存在，但这位天才当时自己也认为黑洞只存在于理论之中。接着在 1931 年诺贝尔奖得主天文学家苏布拉马尼扬．钱德拉赛卡推算出某些高质量的恒星的确会崩坏而成为黑洞，最后也证明他的理论是正确的。后来天文学家发现许多这种现象的例子。

　　当巨大的恒星消失时，只留下一颗体积很小且密度很高的核心。如果这颗核心的质量超过太阳质量约三倍以上，那重力就会压过其他力量而形成黑洞。而大部份黑洞比太阳还要大上十到二十四倍。也有比太阳大上几百万倍的超大黑洞。科学家认为这些神祕的巨物位于广大银河的中心，这当然也包括了我们所处的银河系。

 

答案： 1. C 2. C 3. A 4. B 5. A

6. D 7. B