Black Holes

What is a black hole? Well, it's difficult to answer this question, since the terms we would normally use to describe a scientific phenomenon are inadequate here. Astronomers and scientists think that a black hole is a region of space (not a thing) into which matter has fallen and from which nothing can escape - not even light. So we can't see a black hole. A black hole exerts a strong gravitational pull and yet it has no matter. It is only space - or so we think. How can this happen?

The theory is that some stars explode when their density increases to a particular point; they collapse and sometimes a supernova occurs. From earth, a supernova looks like a very bright light in the sky which shines even in the daytime. Supernovae were reported by astronomers in the seventeenth and eighteenth centuries. Some people think that the Star of Bethlehem could have been a supernova. The collapse of a star may produce a White Dwarf or neutron star - a star, whose matter is so dense that it continually shrinks by the force of its own gravity. But if the star is very large (much bigger than our sun) this process of shrinking may be so intense that a black hole results. Imagine the earth reduced to the size of a marble, but still having the same mass and a stronger gravitational pull, and you have some idea of the force of a black hole. Any matter near the black hole is sucked in. It is impossible to say what happens inside a black hole. Scientists have called the boundary area around the hole the "event horizon." We know nothing about events which happen once objects pass this boundary. But in theory, matter must behave very differently inside the hole.

For example, if a man fell into a black hole, he would think that he reached the center of it very quickly. However an observer at the event horizon would think that the man never reached the center at all. Our space and time laws don't seem to apply to objects in the area of a black hole. Einstein's relativity theory is the only one which can explain such phenomena. Einstein claimed that matter and energy are interchangeable, so that there is no "absolute" time and space. There are no constants at all, and measurements of time and space depend on the position of the observer. They are relative. We do not yet fully understand the implications of the relativity theory; but it is interesting that Einstein's theory provided a basis for the idea of black holes before astronomers started to find some evidence for their existence. It is only recently that astronomers have begun specific research into black hole. In august 1977, a satellite was launched to gather data about the 10 million black holes which are thought to be in the Milky Way. And astronomers are planning a new observatory to study the individual exploding stars believed to be black holes.

The most convincing evidence of black holes comes from research into binary star systems. Binary stars, as their name suggests, are twin stars whose position in space affects each other. In some binary systems, astronomers have shown that there is an invisible companion star, a "partner" to the one which we can see in the sky. Matter from the one which we can see is being pulled towards the companion star. Could this invisible star, which exerts such a great force, be a black hole? Astronomers have evidence of a few other stars too, which might have black holes as companions.

The story of black holes is just beginning. Speculations about them are endless. There might be a massive black hole at the center of our galaxy swallowing up stars at a very rapid rate. Mankind may one day meet this fate. On the other hand, scientists have suggested that very advanced technology could one day make use of the energy of black holes for mankind. These speculations sound like science fiction. But the theory of black holes in space is accepted by many serious scientists and astronomers. They show us a world which operates in a totally different way from our own and they question our most basic experience of space and time.

译文：

黑洞

什么是黑洞呢？这个问题很难回答，因为我们通常用来描述一种科学现象的术语用在这里来解释是不够的。

天文学家和科学家们认为黑洞是个空间区域，物体会掉进去，而没有物体能从中逃逸出来――即使是光也不能，所以我们看不到黑洞。黑洞产生很强的引力，而它却没有物质。它只是空间――或者我们认为是空间。这是怎样发生的呢？

理论是一些星球的密度增长到特定的时刻就会爆炸。它们崩溃时会产生超新星。在地球上看去，超新星就像天空中非常耀眼的灯，即使在白天也能看到其闪光。在17、18世纪，天文学家就有关于超新星的记录，一些人认为圣诞星可能是一颗超新星。一颗星崩溃可能产生吸引力，你就了解黑洞的力量。黑洞附近任何物质都会被吸进去，根本不可能说出黑洞里面发生了什么。科学家们把这个洞的边缘区域称为"事界"。一旦物体经过这个边界，我们对所发生的事一无所知。但是在理论上，在黑洞里的物质的运动肯定与洞外有很大区别。

例如：如果一个人掉进黑洞，他会认为自己很快就达到了其核心，但在"事界"的观察者则认为这个人根本不会到达黑洞的核心。我们的时空规律看起来不适于黑洞里的物体。爱因斯坦的相对论是唯一可以解释这种现象的理论。爱因斯坦声称物质和能量是可以互相转化的，因此就没有绝对的时间和空间，根本不存在永恒，时间和空间的衡量取决于观测者所在的位置，它们是相对的。我们还没有完全理解相对论的含义，但有意思的是，在天文学家的着手发现黑洞的存在证据之前，爱因斯坦就提供了黑洞这种想法的基础。只是近来科学家才开始对黑洞的具体研究。1977年8月，发射了一颗卫星去收集关于被认为是在银河系的一千万个黑洞的数据。天文学家正在计划一个新的天文台以研究个别的正在爆炸的被相信要变为黑洞的星球。

黑洞最有说服力的证据来自对双星系的研究。双星，正如它们的名字所表明的，是两颗在空间位置上互相影响的星球。在一些双星系里，天文学家已经表示这里有一颗看不到的伴星，即我们可以在天空中看到的一颗星球的伙伴。来自我们的看到的星球的物质正被吸引到伴星去。这颗产生如此巨大力量的看不见的星球会是黑洞吗？天文学家还有其他一些星球的证据，这些星球可能与黑洞相伴。

对黑洞的研究刚刚开始，各种推测会层出不穷。在我们银河系的中心很可能存在着一个巨大的黑洞正以极快的速度吞食着星球。人类有一天也会面临被吞食的命运。而科学家提出，有一天高科技利用轩洞的能量为人类服务。这些设想听起来像科幻小说，但空间中黑洞的理论被许多严谨的科学家和天文学家接受。他们向我们展示了一个以完全不同于我们理解的方式运行的世界，并对我们最基本的时空经验提出了疑问。

课文讲解：

一、复习，听写UNIT1-TEXT B 单词

二、单词部分

1.shrink （使）缩短，（使）收缩，畏缩

shrink+副词/介词短语 ：

That sweater shrank in the wash.

The girl shrank back in fear.

Shrink+名词：

This detergent won’t shrink wool 这种洗洁剂不会使毛料收缩。

2．Continually 屡次地、频繁地

It is raining continually.

派生词： continual 不断的、连续的

He had continual complaints about our manner.

近义词： continuously 不断地、连续地

He continuously made mistakes.

3．Result

1)result+from+名词 ：由。。。造成。。。结果、 由。。。引起

The terrible accident resulted from his carelessness. 那桩可怕的事故是因他的疏忽大意引起的。

2)result+in+名词：导致、引起

His attempt resulted in failure. 他的尝试终于失败了。

4．Reduce

1)reduce+名词：把。。。减少、下降、减弱

She reduced her weight by 5 kilograms.

2)Reduce+名词＋to+名词/动名词 ：使。。。变为/成为（可用于被动语态）

The bobs reduced the city to ruins炸弹使那座城市变为废墟

She was reduced to tears at the sight. 她看到那情景就哭了起来。

5．Basis 基础、根据（复数为bases）

His theory has a solid basis in facts. 他的理论有很多事实根据。

6. speculation

1)speculation+about/on upon+名词： 深思、揣想、推测

He made speculations on the purpose of life. 他对人生的目的进行深思。

2)peculation +in+名词： 对。。。投机

Speculation in stocks is a dangerous way of making a fortune. 股票投机是一种危险的发财方式。

7．Swallow

1)swallow+up+名词 ：吞没、吞。。。。

He swallowed up the medicine with water.

2)Swallow+名词： （口语）轻信、忍受

She couldn’t swallow his insults.

三、课文讲解

1、Astronomers and scientists think that a black hole is a region of space (not a thing) into

which matter has fallen and from which nothing can escape – not even light. 天文科学家和科学家认为黑洞是一个空间地带（不是物体），物质掉进去就难逃罗网，甚至连光也跑不了。

关系代词在从句中作介词宾语时，若介词随着关系代词提前，关系代词不能使用that,若介词不提前，则不受此限制。 例如：I didn’t know the matter that/which you referred to. 我不知道你说的那件事。

2、From earth, a supernova looks like a very bright light in the sky which shines even in the daytime. 从地球上看，超新星就像是天空中一盏明亮的灯，即使在白昼中也闪闪发光

1)supernova的复数形式是supernovae.

2)in the daytime 与at night 相反，表示“在白昼” Stars are invisible in the daytime.

3.But if the star is very large （much bigger than our sun）this process of shrinking may be so in tense that a black hole results. 如果恒星非常大（比太阳还大的多），那么其收缩过程就极为剧烈，以至产生了黑洞。

So…that在此引导一个结果状语从句，从句谓语动词用陈述语气，若引导目的状语从句，从句谓语动词则用虚拟语气（can/could/may/might+动词原形）。例如：The writer explained so carefully that the reader could understand better.

Result 在这里是不及物动词，表示“作为结果发生”，经常与介词in和from搭配分别表示“导致”和“是由。。。引起的”。例如：His illness resulted from eating bad food.

4.It is only recently that astronomers have begun specific research into black holes. 只是最近天文学家才真正开始研究黑洞。

这里的强调句式强调的是一个副词短语only recently.

名词research与介词into 搭配表示“对。。。的研究”，与for搭配表示“寻找。。。” 例

如：Scientists carry out a research into the causes of cancer.

Their search for the lost child ended in failure.

5. Binary stars, as their name suggests, are twin stars whose position in space affects each other 顾名思义，双星就是一对恒星，其空间位置相互影响。

As在这里是一个关系代词，as their/its name suggests/ implies表示“顾名思义”。例如：Watchdog, as its name suggests, is kept to guard property.看家狗，顾名思义，是用来看家的。

6．In some binary systems, astronomers have shown that there is an invisible companion star, a “partner” to the one which we can see in the sky. 在一些双星系中，天文学家证明有一种看不见的伴星，即我们能够在天空中看到的那颗星的“伙伴”

a partner to..表示“是。。。的伙伴” He is a good partner to me in business.

7.on the other hand, scientists have suggested that very advanced technology could one day make use of the energy of black holes for mankind. 而科学家们认为，有朝一日高度发达的技术或许能利用黑洞的能量造福人类。

1)one day既可指（过去）有一天，也可以指（将来）总会有一天。 例如：one day we’ll get ourselves a new car.

2)Make use of 表示“利用”，与put…to use意思相同，use前可以有形容词修饰。例如： We should make full use of our natural resources.

8. They show us a world which operates in a totally different way from our own and they question our most basic experience of space and time..他们向我们展示了一个与我们这个世界运行方式完全不同的世界，并对我们最基本的时空体验提出了质疑。

1)Totally 是副词修饰different, 相当于completely.

2)A totally different way from our own 也可以说成a way totally different from our own.Question作及物动词用，表示“向某人提问，质问” She openly questioned the truth of this statement. 她公开对这件事的真实性表示怀疑。