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英语阅读文章长篇

2023-12-07 18:12 来源:学术参考网 作者:未知

英语阅读文章长篇

众所周知,阅读作为人类汲取知识的主要手段和认知世界的主要途径之一,一度成为语文、外语等文科类学科学习的主要方式,而倍受关注和青睐。下面是我带来的英语长篇 文章 阅读,欢迎阅读!

英语长篇文章阅读1

寒武纪大爆发 动物王国出现

Science and technology

The Cambrian explosion

Kingdom come

Chinese palaeontologists hope to explain the rise of the animals

AMONG the mysteries of evolution, one of the most profound is what exactly happened at the beginning of the Cambrian period.

Before that period, which started 541m years ago and ran on for 56m years, life was a modest thing.

Bacteria had been around for about 3 billion years, but for most of this time they had had the Earth to themselves.

Seaweeds, jellyfish-like creatures, sponges and the odd worm do start to put in an appearance a few million years before the Cambrian begins.

But red in tooth and claw the Precambrian was not—for neither teeth nor claws existed.

Then, in the 20m-year blink of a geological eye, animals arrived in force.

Most of the main groups of the animal kingdom—arthropods, brachiopods, coelenterates, echinoderms, molluscs and even chordates, the branch from which vertebrates went on to develop—are found in the fossil beds of the Cambrian.

The sudden evolution of this megafauna is known as the Cambrian explosion.

But two centuries after it was noticed, in the mountains of Wales after which the Cambrian period is named, nobody knows what detonated it.

A group of Chinese scientists, led by Zhu Maoyan of the Nanjing Institute of Geology and Palaeontology, plan to change that with a project called “From the Snowball Earth to the Cambrian explosion: the evolution of life and environment 600m years ago”.

The “Snowball Earth” refers to a series of ice ages that happened between 725m and 541m years ago.

These were, at their maxima, among the most extensive glaciations in the Earth’s history.

They alternated, though, with periods that make the modern tropics seem chilly: the planet’s average temperature was sometimes as high as 50C.

Add the fact that a supercontinent was breaking up at this time, and you have a picture of a world in chaos.

Just the sort of thing that might drive evolution.

Dr Zhu and his colleagues hope to find out exactly how these environmental changes correspond to changes in the fossil record.

The animals’ carnival

Fortunately, China’s fossil record for this period is rich.

Until recently, the only known fossils of Precambrian animals were what is called the Ediacaran fauna—a handful of strange creatures found in Australia, Canada and the English Midlands that lived in the Ediacaran period, between 635m and 541m years ago, and which bear little resemblance to what came afterwards.

In 1998, however, a team led by Chen Junyuan, also of the Nanjing Institute, and another led by Xiao Shuhai of the Virginia Polytechnic Institute, in America, discovered a 580m-year-old Lagersttte—a place where fossils are particularly well preserved—in a geological formation called the Doushantuo, which spreads out across southern China.

Portents of the modern world

This Lagersttte has yielded many previously unknown species, including microscopic sponges, small tubular organisms of unknown nature, things that look like jellyfish but might not be and a range of what appear to be embryos that show bilateral symmetry.

What these embryos would have grown into is unclear. But some might be the ancestors of the Cambrian megafauna.

To try to link the evolution of these species with changes in the environment, Chu Xuelei of the Institute of Geology and Geophysics in Beijing and his colleagues have been looking at carbon isotopes in the Doushantuo rocks.

They have found that the proportion of 12C—a light isotope of carbon that is more easily incorporated by living organisms into organic matter than its heavy cousin, 13C—increased on at least three occasions during the Ediacaran period.

They suggest these increases mark moments when the amount of oxygen in seawater went up, because more oxygen would mean more oxidisation of buried organic matter. That would liberate its 12C, for incorporation into rocks.

Each of Dr Chu’s oxidation events corresponds with an increase in the size, complexity and diversity of life, both plant and animal.

What triggered what, however, is unclear.

There may have been an increase in photosynthesis because there were more algae around.

Or eroded material from newly formed mountains may have buried organic matter that would otherwise have reacted with oxygen, leading to a build-up of the gas.

The last—and most dramatic—rise in oxygen took place towards the end of the Ediacaran.

Follow-up work by Dr Zhu, in nine other sections of the Doushantuo formation, suggests this surge started just after the final Precambrian glacial period about 560m years ago, and went on for 9m years.

These dates overlap with those of signs of oxidation found in rocks in other parts of the world, confirming that whatever was going on affected the entire planet.

Dr Zhu suspects this global environmental shift propelled the evolution of complex animals.

Dr Zhu also plans to push back before the Ediacaran period.

Other researchers have found fossils of algae and wormlike creatures in rocks in northern China that pre-date the end of the Marinoan glaciation, 635m years ago, which marks the boundary between the Ediacaran and the Cryogenian period that precedes it.

Such fossils are hard to study, so Dr Zhu will use new imaging technologies that can look at them without having to clean away the surrounding rock, and are also able to detect traces of fossil organic matter invisible to the eye.

Besides digging back before the Ediacaran, the new project’s researchers also intend to analyse the unfolding of the Cambrian explosion itself by taking advantage of other Lagersttten—for China has several that date from the Cambrian.

Dr Chen, indeed, first made his name in 1984, when he excavated one at Chengjiang in Yunnan province.

It dates from 525m years ago, which make it 20m years older than the most famous CambrianLagersttte in the West, the Burgess shale of British Columbia, in Canada.

The project’s researchers plan to see how, evolutionarily speaking, the various Lagerst?tten relate to one another, to try to determine exactly when different groups of organisms emerged.

They will also look at the chemistry of elements other than carbon and oxygen—particularly nitrogen and phosphorous, which are essential to life, and sulphur, which often indicates the absence of oxygen and is thus antithetical to much animal life.

Dr Zhu hopes to map changes in the distribution of these chemicals across time and space.

He will assess how these changes correlate, whether they are related to weathering, mountain building and the ebb and flow of glaciers, how they could have affected the evolution of life, and how plants and animals might themselves have altered the chemistry of air and sea.

Most ambitiously, Dr Zhu, Dr Xiao and their colleagues hope to drill right through several fossiliferous sites in southern China where Ediacaran rocks turn seamlessly into Cambrian ones.

Such places are valuable because in most parts of the world there is a gap, known as an unconformity, between the Ediacaran and the Cambrian.

Unconformities are places where rocks have been eroded before new ones are deposited, and the widespread Ediacaran-Cambrian unconformity has been a big obstacle to understanding the Cambrian explosion.

With luck, then, a mystery first noticed in the Welsh mountains in the early 19th century will be solved in the Chinese ones in the early 21st.

If it is, the origin of the animal kingdom will have become clear, and an important gap in the history of humanity itself will have been filled.

英语长篇文章阅读2

巴西水资源 无水可喝

Water in Brazil

Nor any drop to drink

Dry weather and a growing population spell rationing

BRAZIL has the world's biggest reserves of fresh water. That most of it sits in the sparsely populated Amazon has not historically stopped Brazilians in the drier, more populous south taking it for granted. No longer. Landlords in S?o Paulo, who are wont to hose down pavements with gallons of potable water, have taken to using brooms instead. Notices in lifts and on the metro implore paulistanos to take shorter showers and re-use coffee mugs.

S?o Paulo state, home to one-fifth of Brazil's population and one-third of its economic activity, is suffering the worst drought since records began in 1930. Pitiful rainfall and high rates of evaporation in scorching heat have caused the volume of water stored in the Cantareira system of reservoirs, which supplies 10m people, to dip below 12% of capacity. This time last year, at the end of what is nominally the wet season, it stood at 64%.

On April 21st the governor, Geraldo Alckmin, warned that from May consumers will be fined for increasing their water use. Those who cut consumption are already rewarded with discounts on their bills. The city will tap three basins supplying other parts of the state, but since these reservoirs have also been hit by drought and supply hydropower plants, fears of blackouts are rising.

Without a downpour, Sabesp, the state water utility, expects Cantareira's levels to sink beneath the pipes which link reservoirs to consumers a week after S?o Paulo hosts the opening game of the football World Cup on June 12th. To tide the city over until rains resume in November, it is installing kit to pump half of the 400 billion litres of reserves beneath the pipes, at a cost of 80m reais. The company says this “dead volume”, never before used, is perfectly treatable. Some experts have expressed concerns about its quality.

Mr Alckmin has not ruled out tightening the spigots. Flow from taps in parts of S?o Paulo has already become a trickle, for which Sabesp blames maintenance work. Widespread cuts could hurt the governor's re-election bid in October. Hours after he announced the latest measures, a thirsty mob set fire to a bus.

Paulistanos use more water than most Brazilians, but lose less of it to leaks: 35%, compared with a national average of 39%. Sabesp, listed on the New York Stock Exchange but majority-owned by the state government, is a paragon of good governance, says John Briscoe, a water expert at Harvard and a former head of the World Bank mission in Brazil.

The problem exposed by the drought is that supply has not kept pace with the rising urban population. Facing a jumble of overlapping municipal, state and federal regulations, investment in storage, distribution and treatment has lagged behind. And not just in S?o Paulo; the national water regulator has warned that 16 projects in the ten biggest cities must be completed by 2015 to prevent chronic water shortages over the next decade. So far only five are finished; work on some has not begun. Short-term measures should keep the water trickling for now. But the well of temporary solutions will eventually run dry.

英语长篇文章阅读3

德国公司的管理 董事会的多元化

Business

Corporate governance in Germany

Diversifying the board

German boards have long been cosy men's clubs. But things are changing

HERMANN JOSEF ABS liked to joke, What's the difference between a doghouse and the supervisory board?

The doghouse is for the dog; the supervisory board is for the cat.

For those unfamiliar with the nuances of German humour, for the cat is slang for something like trash.

The late banker would know: while running Deutsche Bank from 1957 to 1967, he also sat on dozens of supervisory boards.

This was the peak of Deutschland AG, a clique of long-serving bosses, autocratic chairmen, do-nothing board members and their financier friends.

Big German companies' supervisory boards are supposed to act as a check on their management boards.

But in practice their relations were too cosy for this.

This past year the stumbles of two titans seemed to highlight how much corporate power is still concentrated in few hands in the Germanspeaking world.

As 2013 began Gerhard Cromme was chairman of the supervisory boards of both Siemens, an industrial conglomerate, and ThyssenKrupp, a steelmaker.

But big losses at foreign mills and heavy fines over a cartel case cost him the chairmanship at ThyssenKrupp.

Then in July, a boardroom bunfight at Siemens ended with the departure of Peter Lscher, the chief executive.

Mr Cromme belatedly called for his firing—but only after hiring him and protecting him for years.

Josef Ackermann, a Swiss former boss of Deutsche Bank and a Siemens board member, had defended Mr Lscher.

When Mr Lscher went, so did he.

Shortly before this he had quit as chairman of Zurich, a Swiss insurer, whose chief financial officer had committed suicide, leaving a note berating Mr Ackermann.

Now he has no big corporate job, there have been reports that Mr Ackermann may have to step down as a trustee of the World Economic Forum after its gabfest in Davos this week.

At first glance, corporate power in Germany still looks male, German and concentrated.

But its boardrooms are slowly getting more diverse.

In 2003 the average supervisory-board member at a public company sat on 1.9 boards; now the figure is 1.6.

A 2001 cut in tax on sales of shares let banks and insurance companies, which played big roles as lenders and part-owners, start disentangling themselves from companies.

Into the gaps, and onto the boards, has come a new generation of more active members.

Boards have little choice but to be sharper, says Christoph Schalast of Frankfurt School of Finance and Management.

Many companies are now paying fines and settlements for their behaviour before the financial crisis.

A 2010 change in the law doubled the statute of limitations for such misdeeds to ten years.

Progress on making boards more international is slower.

Eight of the largest 30 public companies have foreign bosses, but the rest of their boards' members are predominantly German, even at the country's most multinational firms.

But Burkhard Schwenker, the boss of Roland Berger, a consulting firm, says that counting passports is simplistic: what matters more is international experience, which German firms increasingly look for when recruiting both management-and supervisory-board members.

If boards are becoming more professional and diverse, is accumulation of board seats a bad thing in itself?

Jrg Rocholl, the president of the European School for Management and Technology, says that studies disagree on whether busy board members are better or worse for profits.

But he agrees that boards are becoming more capable, and says this has been a factor in Germany's economic revival.

Pay for German board members is going up; but these days, members are earning it.

长篇英语阅读

有很多
Astronomers have witnessed the biggest bang since the big bang—the moment about 15 billion years ago when the universe was created in a massive explosion. The huge burst of energy from the edge of the universe is estimated to be second only to the moment of creation in its explosive force, releasing more energy in two seconds than the sun will give out in it lifetime. Scientists hope the explosion—known as a gamma-ray burst because it emits energy in the form of gamma radiation—will shed light on the earliest stages in the evolution of the stars and galaxies. Gamma-ray bursts cannot be seen by the human eye, but if they could the sky would light up like a camera flash each time they occurred. They are by far the most energetic events in the universe and, until now, have remained largely a mystery.
The latest gamma-ray burst to be detected accurately occurred last December. Using a network of telescopes and satellites, the astronomers were able to calculate its distance from Earth at about 15 billion light years. This means it must have happened soon after the big bang itself, while the intensity of the radiation revealed it to be the biggest bang recorded by man. Scientists from the American National Aeronautics and Space Administration and the California Institute of Technology are to announce details of their analysis this week. The huge distance between the source of the explosion and the Earth suggests gamma-ray bursts are up to 10 times larger than previously thought, said Jonathan Katz, professor of physics at Washington University in St Louis.
“Gamma-ray bursts may be the most distant things we will ever see and as such will act as beacons to probe into the very distant regions of the universe when stars and galaxies were first formed.”
American spy satellites looking for the radiation released from Soviet nuclear tests first detected gamma-ray bursts in 1967 but the details were kept classified until 1973. For nearly 25 years scientists were hampered in their efforts to find an explanation for the huge explosions because they lasted no longer than a few seconds. The inability to explain them led to speculation that gamma-ray bursts were the remnants of nuclear battles between alien civilizations, or even the exhaust energy of extraterrestrial spaceships going into warp drive. Two satellites, the American Compton gamma-ray observatory and the Italian-Dutch Bepposax satellite, have now been able to locate the precise direction of gamma-ray bursts within seconds of them occurring. John Quenby, professor of physics at Imperial College of Science, Technology and Medicine in London, said the most likely explanation for gamma-ray burst is that they result from the enormous energy released when two very dense objects—called neutron stars—collide

英语文章阅读带翻译3篇

  在世界经济全球化及中国加入WTO的形势下,社会需要大量能够用英语在国际上进行科技、经贸、法律和 文化 等方面交流的专业人才。下面是我带来的英语 文章 阅读带翻译,欢迎阅读!

  英语文章阅读带翻译篇一
  In the public interest

  The Scandinavian countries are much admired all over the world for their enlightened social policies. Sweden has evolved an excellent system for protecting the individual citizen from high-handed or incompetent public officers. The system has worked so well, that it has been adopted in other countries like Denmark, Norway, Finland, and New Zealand. Even countries with large populations like Britain and the United States are seriously considering imitating the Swedes.

  The Swedes were the first to recognize that public officials like civil servants, collectors can make mistakes or act over-zealously in the belief that they are serving the public. As long ago as 1809, the Swedish Parliament introduced a scheme to safeguard the interest of the individual. A parliamentary committee representing all political parties appoints a person who is suitably qualified to investigate private grievances against the State. The official title of the person is 'Justiteombudsman', but the Swedes commonly refer to him as the 'J.O.' or 'Ombudsman'. The Ombudsman is not subject to political pressure. He investigates complaints large and small that come to him from all levels of society. As complaints must be made in writing, the Ombudsman receives an average of 1200 letters a year. He has eight lawyer assistants to help him and he examines every single letter in detail. There is nothing secretive about the Ombudsman's work, for his correspondence is open to public inspection. If a citizen's complaint is justified, the Ombudsman will act on his behalf. The action he takes varies according to the nature of the complaint. He may gently reprimand an official or even suggest to parliament that a law be altered. The following case is a typical example of the Ombudsman's work.

  A foreigner living in a Swedish village wrote to the Ombudsman complaining that he had been ill-treated by the police, simply because he was a foreigner. The Ombudsman immediately wrote to the Chief of Police in the district asking him to send a record of the case. There was nothing in the record to show that the foreigner's complaint was justified and the Chief of Police stoutly denied the accusation. It was impossible for the Ombudsman to take action, but when he received a similar complaint from another foreigner in the same village, he immediately sent one of his lawyers to investigate the matter. The lawyer ascertained that a policeman had indeed dealt roughly with foreigners on several occasions. The fact that the policeman was prejudiced against foreigners could not be recorded in he official files. It was only possible for the Ombudsman to

  find this out by sending one of his representatives to check the facts. The policeman in question was severely reprimanded and was informed that if any further complaints were lodged against him, he would be prosecuted. The Ombudsman's prompt action at once put an end to an unpleasant practice which might have gone unnoticed.

  斯堪的纳维亚半岛各国实行开明的社会政策,受到全世界的推崇。在瑞典,已逐渐形成了一种完善的制度以保护每个公民不受专横的和不称职的政府官员的欺压。由于这种制度行之有效,已被其他国家采纳。

  是瑞典人首先认识到政府工作人员如文职人员、警官、卫生稽查员、税务人员等等也会犯错误或者自以为在为公众服务而把事情做过了头。早在1809年,瑞典论会就建立一个保护公民利益的制度。议会内有一个代表各政党利益的委员会,由它委派一位称职的人选专门调查个人对国家的意见。此人官衔为“司法特派员”,但瑞典人一般管他叫“J.O.”,即“司法特派员”。司法特派员不受任何政治压力的制约。他听取社会各阶层的各种大小意见,并进行调查。由于意见均需用书面形式提出,司法特派员每年平均收到1,200封信。他有8位律师作他的助手协助工作,每封信都详细批阅。司法特派员的工作没有什么秘密可言,他的信件是公开的,供公众监督。如果公民的意见正确,司法特派员便为他伸张正义。司法特员采取的行动因意见的性质不同而有所不同。他可以善意地批评某位官员,也可以甚至向议会提议修改某项法律。下述事件是司法特派员工作的一个典型例子。

  一个住在瑞典乡村的外国人写信给司法特派员,抱怨说他受到警察的虐待,原因就是因为他是个外国人。司法特派员立即写信给当地警察局长,请他寄送与此事有关的材料。材料中没有任何文字记载证明外国人所说的情况符合事实,警察局长矢口否认这一指控。司法特派员难以处理。但是,当他又收到住在同一村庄的另一个外国人写的一封内容类似的投诉信时,他立即派出一位律师前去调查。律师证实有个警察确实多次粗鲁地对待外国人。警察歧视外国人的事在官方档案中不可能加以记载,司法特派员只有派他的代表去核对事实才能了解真相。当事的警察受到严厉的斥责,并被告知,如果再有人投诉他,他将受到起诉。司法特派员及时采取的行动,迅速制止了这一起不愉快的事件,不然这件事可能因未得到人们注意而不了了之。
  英语文章阅读带翻译篇二
  Instinct or cleverness?

  We have been brought up to fear insects. We regard them as unnecessary creatures that do more harm than good. Man continually wages war on item, for they contaminate his food, carry diseases, or devour his crops. They sting or bite without provocation; they fly uninvited into our rooms on summer nights, or beat against our lighted windows. We live in dread not only of unpleasant insects like spiders or wasps, but of quite harmless ones like moths. Reading about them increases our understanding with out dispelling our fears. Knowing that the industrious ant lives in a highly

  organized society does nothing to prevent us from being filled with revulsion when we find hordes of them crawling over a carefully prepared picnic lunch. No matter how much we like honey, or how much we have read about the uncanny sense of direction which bees possess, we have a horror of being stung. Most of our fears are unreasonable, but they are impossible to erase. At the same time, however, insects are strangely fascinaing. We enjoy reading about them, especially when we find that, like the praying mantis, they lead perfectly horrible lives. We enjoy staring at them entranced as they go about their business, unaware (we hope) of our presence. Who has not stood in awe at the sight of a spider pouncing on a fly, or a column of ants triumphantly bearing home an enormous dead beetle ?

  Last summer I spent days in the garden watching thousands of ants crawling up the trunk of my prize peach tree. The tree has grown against a warm wall on a sheltered side of the house. I am especially proud of it, not only because it has survived several severe winters, but because it occasionally produces luscious peaches. During the summer, I noticed that the leaves of the tree were beginning to wither. Clusters of tiny insects called aphides were to be found on the underside of the leaves. They were visited by a laop colony of ants which obtained a sort of honey from them. I immediately embarked on an experiment which, even though it failed to get rid of the ants, kept me fascinated for twenty-four hours. I bound the base of the tree with sticky tape , making it impossible for the ants to reach the aphides. The tape was so sticky that they did not dare to cross it. For a long time, I watched them scurrying around the base of the tree in bewilderment. I even went out at midnight with a torch and noted with satisfaction (and surprise) that the ants were still swarming around the sticky tape without being able to do anything about it. I got up early next morning hoping to find that the ants had given up in despair. Instead, I saw that they had discovered a new route. They were climbing up the wall of the house and then on to the leaves of

  the tree. I realized sadly that I had been completely defeated by their ingenuity. The ants had been quick to find an answer to my thoroughly unscientific methods!

  我们自幼就在对昆虫的惧怕中长大。我们把昆虫当作害多益少的无用东西。人类不断同昆虫斗争,因为昆虫弄脏我们的食物,传播疾病,吞噬庄稼。它们无缘无故地又叮又咬;夏天的晚上,它们未经邀请便飞到我们房间里,或者对着露出亮光的窗户乱扑乱撞。我们在日常生活中,不但憎恶如蜘蛛、黄蜂之类令人讨厌的昆虫,而且憎恶并无大害的飞蛾等。阅读有关昆虫的书能增加我们对它们的了解,却不能消除我们的恐惧的心理。即使知道勤奋的蚂蚁生活具有高度组织性的社会里,当看到大群蚂蚁在我们精心准备的午间野餐上爬行时,我们也无法抑制对它们的反感。不管我们多么爱吃蜂蜜,或读过多少关于蜜蜂具有神秘的识别方向的灵感的书,我们仍然十分害怕被蜂蜇。我们的恐惧大部分是没有道理的,但去无法消除。同时,不知为什么昆虫又是迷人的。我们喜欢看有关昆虫的书,尤其是当我们了解螳螂等过着一种令人生畏的生活时,就更加爱读有关昆虫的书了。我们喜欢入迷地看它们做事,它们不知道(但愿如此)我们就在它们身边。当看到蜘蛛扑向一只苍蝇时,一队蚂蚁抬着一只巨大的死甲虫凯旋归时,谁能不感到敬畏呢?

  去年夏天,我花了好几天时间站在花园里观察成千只蚂蚁爬上我那棵心爱的桃树的树干。那棵树是靠着房子有遮挡的一面暖墙生长的。我为这棵树感到特别自豪,不仅因为它度过了几个寒冬终于活了下来,而且还因为它有时结出些甘甜的桃子来。到了夏天,我发现树叶开始枯萎,结果在树叶背面找到成串的叫作蚜虫小虫子。蚜虫遭到一窝蚂蚁的攻击,蚂蚁从它们身上可以获得一种蜜。我当即动手作了一项试验,这项试验尽管没有使我摆脱这些蚂蚁,却使我着迷了24小时。我用一条胶带把桃树底部包上,不让蚂蚁接近蚜虫。胶带极粘,蚂蚁不敢从上面爬过。在很长一段时间里,我看见蚂蚁围着大树底部来回转悠,不知所措。半夜,我还拿着电筒来到花园里,满意地(同时惊奇地)发现那些蚂蚁还围着胶带团团转。无能为力。第二天早上,我起床后希望看见蚂蚁已因无望而放弃了尝试,结果却发现它们又找到一条新的路径。它们正在顺着房子的外墙往上爬,然后爬上树叶。我懊丧地感到败在了足智多谋的蚂蚁的手下。蚂蚁已很快找到了相应的对策,来对付我那套完全不科学的办法!
  英语文章阅读带翻译篇三
  From the earth: greatings

  Radio astronomy has greatly increased our understanding of the universe. Radio telescopes have one big advantage over conventional telescopes in that they can operate in all weather conditions and can pick up signals coming from very distant stars. These signals are produced by colliding stars or nuclear reactions in outer space. The most powerful signals that have been received have been emitted by what seem to be truly colossal stars which scientists have named 'quasars'.

  A better understanding of these phenomena may completely alter our conception of the nature of the universe. The radio telescope at Jodrell Bank in England was for many years the largest in the world. A new telescope, over twice the size, was recently built at Sugar Grove in West Virginia. Astronomers no longer regard as fanciful the idea that they may one day pick up signals which have been sent by intelligent beings on other worlds. This possibility gives rise to interesting speculations. Highly advanced civilizations may have existed on other planets long before intelligent forms of life evolved on the earth. Conversely, intelligent being which are just beginning to develop on remote worlds may be ready to pick up our signals in thousands of years' time, or when life on earth has become extinct. Such speculations no longer belong to the realm of science fiction, for astronomers are now exploring the chances of communicating with living creatures (if they exist) on distant planets. This undertaking which has been named Project Ozma was begun in 1960, but it may take a great many years before results are obtained.

  Aware of the fact that it would be impossible to wait thousands or millions of years to receive an answer from a distant planet, scientists engaged in Project Ozma are concentrating their attention on stars which are relatively close. One of the most likely stars is Tau Ceti which is eleven light years away. If signals from the earth were received by intelligent creatures on a planet circling this

  star, we would have to wait twenty-two years for an answer. The Green Bank telescope in West Virginia has been specially designed to distinguish between random signals and signals which might be in code. Even if contact were eventually established, astronomers would not be able to rely on language to communicate with other beings. They would use mathematics as this is the

  only truly universal language. Numbers have the same value anywhere. For this reason, intelligent creatures in any part of the universe would be able to understand a simple arithmetical sequence. They would be able to reply to our signals using similar methods. The next step would be to try to develop means for sending television pictures. A single picture would tell us more than thousands of words. In an age when anything seems to be possible, it would be narrow-minded in the extreme to ridicule these attempts to find out if there is life in other parts of the universe.

  天文学方面最新发展使得我们能够在银河系和其他星系发现行星。这是一个重要的成就,因为相对来说,行星很小,而且也不发光。寻找行星证明相当困难,但是要在行星上发现生命会变得无比艰难。第一个需要解答的问题是一颗行星是否有能够维持生命的条件。举例来说,在我们的太阳系里,对于生命来说,金星的温度太高,而火星的温度则太低。只有地球提供理想的条件,而即使在这里,植物和动物的进化也用了40亿年的时间。

  一颗行星是否能够维持生命取决于它的恒星——即它的“太阳”——的大小和亮度。设想一下,一颗恒星比我们的太阳还要大,还要亮,还要热20倍,那么一颗行星为了维持生命就要离开的它的恒星非常远。反之,如果恒星很小,维持生命的行星就要在离恒星很近的轨道上运行,而且要有极好的条件才能使生命得以发展,但是,我们如何才能找到这样一颗行星呢?现在,没有一台现存的望远镜可以发现生命的存在。而开发这样一台望远镜将会是21世纪天文学的一个重要的研究课题。

  使用放置在地球上的望远镜是无法观察到其他行星的生命的。地球周围温暖的大气层和望远镜散出的热量使得我们根本不可能找到比行星更小的物体。即使是一台放置在围绕地球的轨道上的望远镜——如非常成功的哈勃望远镜——也因为太阳系中的尘埃微粒而无法胜任。望远镜要放置在木星那样遥远的行星上才有可能在外层空间搜寻生命。因为我们越是接近太阳系的边缘,尘埃就越稀薄。一旦我们找到这样一颗行星,我们就要想办法将它的恒星射过来的光线遮暗,这样我们就能彻底“看见”这颗行星,并分析它的大气层。首先我们要寻找植物,而不是那种“小绿人”。行星上最容易生存下来的是细菌。正是细菌生产出我们在地球上呼吸的氧气。在地球上发展的大部分进程中,细菌是地球上唯一的生命形式。作为地球上的居民,我们总存有这样的希望:小绿人来 拜访 我们,而我们可以和他们交流。但是,这种希望总是只在科幻小说中存在。如果我们能够在另一颗行星上找到诸如细菌的那种低等生命,那么这个发现将彻底改变我们对我们自己的看法。正如美国国家航空和宇宙航空局的丹尼尔.戈尔丁指出的“在其他地方发现生命会改变一切。任何人类的努力和想法都会发生变化。”

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