黑洞

　　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?

　　什么是黑洞?說(shuō)起來(lái)，很難回答這個(gè)問(wèn)題，因?yàn)橥ǔＮ覀冇脕?lái)描述科學(xué)現(xiàn)象的這個(gè)術(shù)語(yǔ)在這里就不恰當(dāng)了。天文學(xué)家和科學(xué)家認(rèn)為，黑洞是一片空間區(qū)域(而不是某個(gè)東西)，物質(zhì)掉落其中，但什么也不能從中逃逸――甚至連光也不能。所以，我們看不見(jiàn)黑洞。黑洞產(chǎn)生很強(qiáng)的引力，但卻不具有物質(zhì);它只是空間，或者說(shuō)我們這樣認(rèn)為。黑洞是怎樣產(chǎn)生的呢?

　　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 a 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.

　　從理論上講，一些恒星的密度增加到某一程度就會(huì)爆炸;這些恒星崩潰瓦解，有時(shí)產(chǎn)生超新星。從地球上看，超新星像天空中一盞明亮的燈，白天也能發(fā)光。天文學(xué)家在十七、十八世紀(jì)對(duì)超新星就有所報(bào)道。有些人認(rèn)為，圣誕星可能是一顆超新星。恒星的崩潰瓦解可能產(chǎn)生白矮星或中子星，這種星的物質(zhì)密度極大，使它在自身引力的作用下不停地收縮。如果這種星體非常大(遠(yuǎn)比太陽(yáng)大)，它的收縮非常劇烈，就會(huì)產(chǎn)生黑洞。試想一下，如果地球縮小到彈子球那么大，但仍具有同樣的質(zhì)量和更強(qiáng)的引力，你就會(huì)對(duì)黑洞的引力有所認(rèn)識(shí)。任何靠近黑洞的物質(zhì)會(huì)被吸了進(jìn)去，卻不能說(shuō)明在黑洞內(nèi)部發(fā)生了什么。科學(xué)家們稱黑洞邊緣地區(qū)為“事界”。對(duì)于通過(guò)這個(gè)邊界時(shí)物體究竟發(fā)生了些什么事件，我們一無(wú)所知。從理論上講，物質(zhì)在黑洞里面的屬性一定會(huì)截然不同。

　　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 holes. 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.

　　打個(gè)比方，如果一個(gè)人落入黑洞，他會(huì)想自己很快就到達(dá)了黑洞中心，而在世界上的觀察者會(huì)認(rèn)為這個(gè)人根本沒(méi)有到達(dá)黑洞中心。看來(lái)我們的時(shí)空觀念并不適用于黑洞區(qū)域的物體。只有愛(ài)因斯坦的相對(duì)論才能解釋這種現(xiàn)象。他說(shuō)，物質(zhì)與能量是相互轉(zhuǎn)換的，因此不存在“絕對(duì)”的時(shí)間與空間，不存在常量;時(shí)間與空間的測(cè)量取決于觀測(cè)者的位置，它們二者是相對(duì)的。我們?nèi)晕赐笍氐乩斫庀鄬?duì)論的意義，但有趣的是，在天文學(xué)家開(kāi)始尋找黑洞存在的證據(jù)之前，愛(ài)因斯坦的理論就為黑洞學(xué)說(shuō)提供了理論基礎(chǔ)。直到最近，天文學(xué)家才開(kāi)始對(duì)黑洞進(jìn)行專門的研究。1997年8月發(fā)射了一顆衛(wèi)星，搜集關(guān)于人們認(rèn)為存在于銀河系中的一千萬(wàn)個(gè)黑洞的數(shù)據(jù)資料。天文學(xué)家還計(jì)劃建一個(gè)新的天文觀測(cè)站，對(duì)那些正在爆炸的、人們認(rèn)為可能會(huì)成為黑洞的恒星分別進(jìn)行研究。

　　The most convincing evidence of black holes comes frown 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.

　　對(duì)雙星星系的研究為黑洞的存在提供了最令人信服的證據(jù)。雙星，顧名思義就是兩顆恒星，其空間位置相互影響。天文學(xué)家們已經(jīng)表明，在一些雙星系中都有一顆看不見(jiàn)的“伴星”，陪伴著天空中我們能夠看得見(jiàn)的星。那顆可見(jiàn)的恒星上的物質(zhì)一直被一顆看不見(jiàn)的另一顆恒星吸引著。這顆產(chǎn)生如此之大引力的不可見(jiàn)恒星會(huì)不會(huì)是個(gè)黑洞呢?天文學(xué)家們已有幾顆其他恒星的證據(jù)，證明它們可能會(huì)有黑洞作為陪伴。

　　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.

　　黑洞理論僅僅是個(gè)開(kāi)始，關(guān)于黑洞的猜測(cè)卻是不勝枚舉。在我們銀河系中心可能有一個(gè)巨大的黑洞，高速吞噬著恒星，人類可能會(huì)在某一天要面臨這一命運(yùn)。另一方面，科學(xué)家們已經(jīng)提出，也許有一天高科技會(huì)利用黑洞的能量為人類造福。這些假想聽(tīng)起來(lái)像科幻故事，然而，空間黑洞的理論已為許多嚴(yán)謹(jǐn)?shù)目茖W(xué)家和天文學(xué)家所接受。他們向我們展示了一個(gè)運(yùn)轉(zhuǎn)方式完全不同于我們這個(gè)世界的世界，他們對(duì)我們關(guān)于時(shí)空的最基本認(rèn)識(shí)提出了質(zhì)疑。

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