Is there any life out there
The second article is about the exploration of extraterrestrial life. The article is divided into five paragraphs, which respectively introduce the reasons for searching for life on other planets, the basic principles of searching, the possibility of life on other planets, the search for radio signals, and how to make appropriate responses. The following is the translation of each paragraph:
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IELTS True Question Reading Vocabulary Cambridge IELTS 9 test 1 passage 2 Is there life outside the planet
Is there any life out there
Cambridge IELTS 9 Test1 Passage2 Reading original translation
introduction
The question of whether we are alone in the Universe has haunted humanity for centuries, but we may now stand poised on the brick of the answer to that question, as the search for radio signals from other intelligent civilizations. This search, often known by the acronym SETI (search for extra-terrestrial intelligence), is a difficult one. Although groups around the world have been searching intermittently for three decades, it is only now that we have reached the level of technology where we can make a determined attempt to search all nearby stars for any sign of life.
The question whether we exist alone in the universe has puzzled mankind for hundreds of years. But with the search for radio signals from other civilizations, we may now be on the verge of solving the problem. This kind of search is usually known for the acronym SETI (search for external intelligence), which is a difficult task. Although groups around the world have searched intermittently for 30 years, we have not reached the corresponding technical level until now, so that we can firmly try to search all nearby stars for signs of life.
Part A
The primary reason for the search is basic curiosity—the same curiosity about the natural world that drives all pure science. We want to know whether life evolves naturally if given the right conditions, or whether there is something very special about the Earth to have fostered the variety of life forms that we see around us on the planet. The simple detection of a radio signal will be sufficient to answer this most basic of all the questions. In this sense, SETI is another cog in the machinery of pure science which is continually pushing out the horizon of our knowledge. However, there are other reasons for being interested in whether life exists elsewhere. For example, we have had civilization on Earth for perhaps only a few thousand years, and the threats of the nuclear war and pollution over the last few decades have told us that our survival may be tenuous. Will we last another two thousand years or will we wipe ourselves out? Since the lifetime of a planet like ours is several billion years, we can expect that, if other civilizations do survive in our galaxy, their ages will range from zero to several billion years. Thus any mere existence of such a civilization will tell us that long-term survival is possible, and gives us some cause for optimism. It is even possible that the older civilization may pass on the benefits of their experience in dealing with threats to survival such as nuclear war and global pollution, and other threats that we haven’t yet discovered.
The main reason for searching is basic curiosity - curiosity about the natural world drives all science forward. We want to know whether we exist alone in the universe; We want to know whether life will naturally evolve if the conditions are suitable, or whether there is something special on the earth, which has bred various life forms we see on the earth. The simple detection of radio signals is enough to answer all these basic questions. In this sense, SETI is another gear in the pure scientific machine, which is constantly promoting the development of our knowledge. But there are other reasons why we are interested in whether there is life elsewhere. For example, our civilization on the earth may have a history of only a few thousand years, but the threat of nuclear war and pollution in the past few decades tells us that our survival may be very fragile. Will we continue for another 2000 years, or will we lead to self destruction? Since planets like the Earth have a lifespan of billions of years, we can expect that if other civilizations do survive in our Milky Way, their ages will be between zero and billions of years. Therefore, any other civilization we hear may be much older than ourselves. Such a civilization itself can tell us that long-term survival is possible and give us some reasons for optimism. When dealing with survival threats (such as nuclear war and global pollution) and other threats that we have not yet discovered, older civilizations may even pass on some of their experiences.
Part B
In discussing whether we are alone, most SETI scientists adopt two ground rules. First, UFOs (Unidentified Flying Objects) are generally ignored since most scientists don’t consider the evidence for them to be strong enough to bear serious consideration although it is also important to keep an open mind in case any really convincing evidence emerges in the future. Second, we make a very conservative assumption that we are looking for a life form that is pretty well like us, since if it differs radically from us we may well not recognize it as a life form, quite apart from whether we are able to communicate with it. In other words, the life form we are looking for may well have two green heads and seven fingers, but it will nevertheless resemble us in that it should communicate with its fellows, be interested in the Universe, live on a planet orbiting a star like our Sun, and perhaps most restrictively, have a chemistry, like us, based on carbon and water.
When discussing whether we exist alone, most SETI scientists adopt two basic rules. First of all, UFOs (unidentified flying objects) are usually ignored, because most scientists believe that the articles are from the old roast duck IELTS, and the evidence they provide is not enough for serious consideration (although it is also important to keep an open attitude when there is any really convincing evidence in the future). Secondly, we make a very conservative assumption that we are looking for a life form that is very similar to us, because if it is completely different from us, we may not think it is a life form. It is not whether we can communicate with it. In other words, the life form we are looking for may have two green heads and seven fingers, but it is still similar to us, because it should communicate with its companions, be interested in the universe, live on a planet orbiting a star like the sun, and perhaps the most restrictive condition is that it has the same chemical structure as us, Built on carbon and water.
Part C
Even when we make these assumptions, our understanding of other life forms is still severely limited. We do not even know, for example, how many stars have planets, and we certainly do not know how likely it is that life will arise naturally, given the right conditions. However, when we look at the 100 billion stars in our galaxy (the milky way), and 100 billion galaxies in the observable Universe, it seems inconceivable that at least one of these planets does not have a life form on it: in fact, the best educated guess we can make, using the little we do know about the conditions for carbon-based life, leads us to estimate that perhaps one in 100,000 stars might have a life-bearing planet orbiting it. That means that our nearest neighbours are perhaps 100 light years away, which is almost next door in astronomical terms.
Even if we make these assumptions, our understanding of other life forms is still severely limited. For example, we don't even know how many stars have planets, and we certainly don't know the possibility of natural life under appropriate conditions. However, when we observe 100 billion stars in the Milky Way and 100 billion galaxies in the observable universe, it seems impossible to imagine that none of these planets has life: in fact, we know very little about the birth conditions of carbon based life, and the best guess we can make makes us estimate that, Every 100000 stars may have a living planet orbiting it. This means that we may be 100 light years away from our nearest neighbor. Astronomically, this is almost the next door.
Part D
An alien civilization could choose many different ways of sending information across the galaxy, but many of these either require too much energy, or else are severely attenuated while traversing the vast distances across the galaxy. It turns out that, for a given amount of transmitted power, radio waves in the frequency range 1000 to 3000 MHz travel the greatest distance, and so all searches to date have concentrated on looking for radio waves in this frequency range. So far there have been a number of searches by various groups around the world, including Australian searches using the radio telescope at Parkes, New South Wales. Until now there have not been any detections from the few hundred stars which have been searched. The scale of the searches has been increased dramatically since 1992, when the US Congress NASA 110 million per year for ten years to conduct a thorough search for extra terrestrial life. Much of the money in this project is being spent on the developing the special hardware needed to search many frequencies at once. The project has two parts. One part is a targeted search using the world’s largest radio telescopes, the America-operated telescope in Arecibo, Puerto Rico and the French telescope in Nancy in France. This part of the project is searching the nearest 1000 likely stars with high sensitivity for signals in the frequency range 1000 to 3000 MHz. The other part of the project is an undirected search which is monitoring all of space with a lower sensitivity, using the smaller antennas of NASA’s Deep Space Network.
Alien civilizations can choose many different ways to send messages between galaxies, but many of them either need too much energy, or will seriously decay when crossing the huge distance of galaxies. It has been proved that for a given transmission power, the distance of radio wave propagation in the frequency range of 1000 to 3000 MHz is the farthest. So far, all searches have focused on finding radio waves within the frequency range. At present, various groups around the world have carried out many searches, including Australia's use of the radio telescope in Parks, New South Wales. So far, no discovery has been found from the hundreds of stars that have been searched. Since 1992, the scale of search has increased dramatically. At that time, the United States Congress gave NASA $100 million annually to conduct in-depth search for extraterrestrial life for ten consecutive years. Most of the money in this project is spent on developing special hardware that can search multiple frequencies at the same time. The project is divided into two parts. One part is to use the world's largest radio telescope for targeted search. This part of the project is searching the nearest 1000 stars with high sensitivity to find signals in the frequency range of 1000 to 3000 MHz. The other part of the project is the non directed search. It uses small antennas from NASA's Deep Space Network to monitor all spaces with low sensitivity.
Part E
There is considerable debate over how we should react if we detect a signal from an alien civilization. Everybody agrees that we should not reply immediately. Quite apart from the impracticality of sending a reply over such large distances at short notice, it raises a host of ethical questions that would have to be addressed by the global community before any reply could be sent. Would the human race face the culture shock if faced with a superior and much older civilization? Luckily, there is no urgency about this. The stars being searched are hundreds of light years away, so it takes hundreds of years for their signal to reach us, and a further few hundreds for our reply to reach them. It’s not important, then, if there’s a delay of a few years, or decades. While the human race debates the question of whether to reply, and perhaps carefully drafts a reply.
There are many arguments about how we should respond if we detect signals from foreign civilizations. Everyone agrees that we should not answer immediately. In addition to the impracticality of sending replies across such a huge distance in such a short time, it also raises many ethical issues that the international community must address before sending any reply. If human beings are faced with superior and ancient civilizations, will they face the impact of culture? Fortunately, this issue is not urgent. The stars searched are hundreds of light years away from us, so it will take hundreds of years for their signals to reach us, and it will take hundreds of years for our replies to reach them. Therefore, a delay of several years or decades is not important. When human beings debate whether to answer the question, they may have to carefully draft the answer.
William Henry Perkin, inventor of synthetic dyes
The history of the tortoise
