老托福听力30篇下载之天文学家(原文+翻译)

目录97.5 (2)97.8 (2)97.10 (3)98.1 (5)98.5 (7)98.8 (9)98.10 (11)99.1 (13)99.5 (15)99.8 (16)99.10 (19)00.1 (21)00.5 (23)00.8 (24)00.10 (25)01.1 (26)01.5 (27)01.8 (28)01.10 (29)PART C97.5很高兴，这么多人对外层空间生存的系列节目感兴趣。

别介意摄象机。

我们将为当地的电台录制节目。

今天晚上我将谈论生存的最基本条件：宇航服。

当你们大多数人想到宇航员时，这也许是首先被想到的事情，对吗？好，没有宇航服我们就不可能在太空生存。

例如，太空是真空的。

那里没有引力和气压。

没有保护，人的身体就会爆炸。

而且，我们会在太阳下灼烧，在荫凉处冻僵，那时气温从零上300华氏到零下300华氏度。

由(美国)国家航空和宇宙航行局研制开发的宇航服确实是一个奇迹。

这张将人放大的照片照的是(往返于地球和太空站之间运载人和物资的)航天飞机上的宇航员穿着的真正的宇航服。

这是躯干部分，它有7层极其耐用的层组成。

这层厚的绝缘层是防止极冷极热温度和射线的。

下一层是被我们称做氧气囊的装置。

它是可以冲气的带子，用来冲氧气模拟大气压。

这个带子给身体以在地球海平面上同样压力。

最里层提供液体冷却和通风。

尽管层数很多，但它很灵活，允许自由的活动，因此可以穿着走路。

宇航服另外一个很复杂的部分是头盔。

我带来了一个，展示给你们看。

有没有自愿上来展示的。

National Aeronautics and Space Administration[video tape recorder n.(磁带)录像机(=VTR)]由学生组织赞助主办的活动大家晚上好，我的名字叫Pan Joans, 代表现代舞俱乐部，我欢迎大家收看今晚的节目。

这个俱乐部很高兴为大家展示电视版的Catherine Wheel轮转烟火. Twyla Tharp 的摇滚芭蕾舞。

托福听力背景材料——天文学(1宇宙与星系随着更强大望远镜的发明和科学技术的进步, 人类开始逐步深入探索宇宙的奥秘。

宇宙有多老 ? 宇宙中是否还有其他生命体 ? 宇宙有多大 ? 根据哈勃望远镜测算到宇宙的年龄是:130亿年到 170亿年之间。

所来一个偶然的发明, 使人们接收到宇宙微波辐射背景, 这就推算出宇宙的年龄是 137亿年, 这项技术因此还得了诺贝尔奖。

而在学科上, 也出现了一个新的学科——天体生物学。

天体生物学(astrobiology是天文学和生物学的交叉学科。

这个学科主要研究陨石中的微生物。

而这些微生物是可以随着陨石在不同的行星 (Planets之间转移的。

宇宙过于浩瀚,故而,天文学家需要划分出一些区域进行研究。

星系、星云、星群、星族、星座都是被划分出来的研究区域。

其中, 星系是最大的区域, 比如我们地球所处的银河系就是众多星系中的一个。

然而, 早期望远镜没有现在这么发达, 科学家还常常把星系误判断为星云, 比如现在我们银河系的邻居——大、小麦哲伦星云其实是星系。

星系与星系之间存在互相作用并进行吞噬, 银河系吸引临近的星系就像地球和月亮间的潮汐力吸引一样。

银河系会以它强烈的引力进行吞噬。

银河系对这个星系是有影响的:一方面吸收了它的星球 ; 另一方面改变了它的形状, 拉长它的形状最终破坏它。

天文学家还发现银河系中的某些缺金属元素的“高速星云” , 这些高速星云中和了新星上形成的金属元素。

这些星云起着维持银河系中星云平衡以便生成新星的作用月球的南极艾特肯盆地 (TPO1. 南极 -艾特肯盆地 (South Pole-Aitken basin.简称为 SPAB月球上最大的环形山 , 同时也是太阳系内已知最大的 , 形成了 South Pole-Aitken basin(SPAB。

这个环形山位于月球的背面, 接近南极的 Aitken 盆地, 直径约 2, 500 千米, 深 12千米。

该盆地层略有升高丰度的铁,钛,和钍等化学元素。

今天，环球托福为备考托福听力的考友们带来托福TPO听力文本翻译Lecture1Astronomy （上），帮助大家复习托福听力以及分析听力文章的重点通常出现在哪些关键词后。

下面，请看环球托福分享的托福TPO听力文本：Geocentric&Heliocentric theoryNarrator Listen to part of a lecture in a history of science class. Aristarchus-Heliocentric Theory ProfessorOk, we have been talking about how throughout history, it was often difficult for people to give up ideas which have long been taken for granted as scientific truth, even if those ideas were false. In Astronomy, for example, the distinction between the solar system and the universe wasn’t clear until modern times. The ancient Greeks believed that what we called the solar system was in fact the entire universe, and that the universe was geocentric. Geocentric means Earth-centered, so the geocentric view holds that the Sun, the planets, and the stars, all revolve around the Earth, which is stationary. Of course, we now know that the planets, including Earth, revolve around the Sun, and that the solar system is only a tiny part of the universe.托福TPO听力文本翻译我们已经讨论过，纵观历史，当人们要放弃长久以来已经被理所当然地视为科学真理的观点，是如何的困难，即使这些观点是错的。

Mathematical Astronomy1.A brief history of cosmologyFour thousand years ago the Babylonians were skilled astronomers who were able to predict the apparent motions of the moon and the stars and the planets and the Sun upon the sky, and could even predict eclipses. But it was the Ancient Greeks who were the first to build a cosmological model within which to interpret these motions. In the fourth century BC, they developed the idea that the stars were fixed on a celestial sphere which rotated about the spherical Earth every 24 hours, and the planets, the Sun and the Moon, moved in the ether between the Earth and the stars. This model was further developed in the following centuries, culminating in the second century AD with Ptolemy's great system. Perfect motion should be in circles, so the stars and planets, being heavenly objects, moved in circles. However, to account for the complicated motion of the planets, which appear to periodically loop back upon themselves, epicycles had to be introduced so that the planets moved in circles upon circles about the fixed Earth.Despite its complicated structure, Ptolemy produced a model so successful at reproducing the apparent motion of the planets that when, in the sixteenth century, Copernicus proposed a heliocentric system, he could not match the accuracy of Ptolemy's Earth-centred system. Copernicus constructed a model where the Earth rotated and, together with the other planets, moved in a circular orbit about the Sun. But the observational evidence of the time favoured the Ptolemaic system!There were other practical reasons why many astronomers of the time rejected the Copernican notion that the Earth orbited the Sun. Tycho Brahe was the greatest astronomer of his the sixteenth century. He realised that if the Earth was moving about the Sun, then the relative positions of the stars should change as viewed from different parts of the Earth's orbit. But there was no evidence of this shift, called parallax. Either the Earth was fixed, or else the stars would have to be fantastically far away.It was only with the aid of the newly-invented telescope in the early seventeenth century that Galileo could deal a fatal blow to the notion that the Earth was at the centre of the Universe. He discovered moons orbiting the planet Jupiter. And if moons could orbit another planet, why could not the planets orbit the Sun?At the same time, Tycho Brahe's assistant Kepler discovered the key to building a heliocentric model. The planets moved in ellipses, not perfect circles, about the Sun. Newton later showed that elliptical motion could be explained by his inverse-square law for the gravitational force.But the absence of any observable parallax in the apparent positions of the stars as the Earth rotated the Sun, then implied that the stars must be at a huge distance from the Sun. The cosmos seemed to be a vast sea of stars. With the aid of his telescope, Galileo could resolve thousands of new stars which were invisible to the naked eye. Newton concluded that the Universe must be an infinite and eternal sea of stars, each much like our own Sun.It was not until in the nineteenth century that the astronomer and mathematicianBessel finally measured the distance to the stars by parallax. The nearest star (other than the Sun) turned out to be about 25 million, million miles away! (By contrast the Sun is a mere 93 million miles away from the Earth.)Most of the stars we can see are contained in the Milky Way - the bright band of stars that stretches across our night sky. Kant and others proposed that our Milky Way was in fact a lens shaped "island universe'' or galaxy, and that beyond our own Milky Way must be other galaxies.As well as stars and planets, astronomers had noted fuzzy patches of light on the night sky, which they called nebulae. Some astronomers thought these could be distant galaxies. It was only in the 1920's that the American astronomer Hubble established that some of these nebulae were indeed distant galaxies comparable in size to our own Milky Way.Hubble also made the remarkable discovery that these galaxies seemed to be moving away from us, with a speed proportional to their distance from us. It was soon realised that this had a very natural explanation in terms of Einstein's recently discovered General Theory of Relativity: our Universe is expanding!In fact, Einstein might have predicted that the Universe is expanding after he first proposed his theory in 1915. Matter tends to fall together under gravity so it was impossible to have a static universe. However, Einstein realised he could introduce a arbitrary constant into his mathematical equations, which could balance the gravitational force and keep the galaxies apart. This became known as the cosmological constant. After it was discovered that the Universe wa s actually expanding, Einstein declared that introducing the cosmological constant was the greatest blunder of his life!The Russian mathematician and meteorologist Friedmann had realised in 1917 that Einstein equations could describe an expanding universe. This solution implied that the Universe had been born at one moment, about ten thousand million years ago in the past and the galaxies were still travelling away from us after that initial burst. All the matter, indeed the Universe itself, was created at just one instant. The British astronomer Fred Hoyle dismissively called it the "Big Bang'', and the name stuck. There was a rival model, called the Steady State theory - advocated by Bondi, Gold and Hoyle - developed to explain the expansion of the Universe. This required the continuous creation of matter to produce new galaxies as the universe expanded, ensuring that the Universe could be expanding, but still unchanging in time.For many years it seemed a purely academic point, whether the universe was eternal and unchanging, or had only existed for a finite length of time. But a decisive blow was dealt to the Steady State model when in 1965 Penzias and Wilson discovered a cosmic microwave background radiation. This was interpreted as the faint afterglo w of the intense radiation of a Hot Big Bang, which had been predicted by Alpher and Hermann back in 1949.Following on from earlier work by Gamow, Alpher and Herman in the 1940's, theorists calculated the relative abundances of the elements hydrogen and helium that might be produced in a Hot Big Bang and found it was in good agreement with the observations. When the abundance of other light elements was calculated these toowere consistent with the values observed.Since the 1970's almost all cosmologists have come to accept the Hot Big Bang model and have begun asking more specific, but still fundamental, questions about our Universe. How did the galaxies and clusters of galaxies that we observe today form out of the primordial expansion. What is most of the matter in the Universe made of? How do we know that there are not black holes or some kind of dark matter out there which does not shine like stars? General relativity tells us that matter curves space-time, so what shape is the Universe? Is there a cosmological constant after all? We are only beginning to find answers to some of these questions. The cosmic microwave background radiation plays a key role as it gives us a picture of the universe as it was only a hundred thousand years after the Big Bang. It turns out to be so remarkably uniform, that it was only in 1992 that NASA's Cosmic Background Explorer satellite detected the first anisotropies in this background radiation. There are slight fluctuations in the temperature of the radiation, about one part in a hundred thousand, which may be the seeds from which galaxies formed.Since the early 1980's there has been an explosion of interest in the physics of the early universe. New technology and satellite experiments, such as the Hubble Space Telescope, have brought us an ever improving picture of our Universe, inspiring theorists to produce ever more daring models, drawing upon the latest ideas in relativity and particle physics.2.Greek astronomyToday the study of astronomy requires a deep understanding of mathematics and physics. It is important to realise that Greek astronomy (we are interested in the topic during the 1000 years between 700 BC and 300 AD) did not involve physics. Indeed, as Pannekoek points out in [7], a Greek astronomer aimed only to describe the heavens while a Greek physicist sought out physical truth. Mathematics provided the means of description, so astronomy during the 1000 years that interest us in this article was one of the branches of mathematics.The Greeks began to think of philosophy from the time of Thales in about 600 BC. Thales himself, although famed for his prediction of an eclipse, probably had little knowledge of astronomy, yet he brought back from Egypt knowledge of mathematics into the Greek world and possibly also some knowledge of Babylonian astronomy. It is reasonable to begin by looking at what 'astronomy' was in Greece around this time. However we begin by looking further back than this to around 700 BC.Basically at this time astronomy was all to do with time keeping. It is natural that astronomical events such as the day would make a natural period of time and likewise the periodic phases of the moon make the next natural time span. Indeed these provided the basic methods of time keeping around the period of 700 BC yet, of course, another important period of time, the year, was not easy to determine in terms of months. Y et a knowledge of the approximate length of the year was vital for food production and so schemes had to be devised. Farmers at this time would base their planting strategies on the rising and setting of the constellations, that is the times when certain constellations would first become visible before sunrise or were last visible after sunset.Hesiad, one of the earliest Greek poets, often called the "father of Greek didactic poetry" wrote around 700 BC. Two of his complete epics have survived, the one relevant to us here is Works and Days describing peasant life. In this work Hesiad writes that (see [5], also [1] and [7]):-... when the Pleiades rise it is time to use the sickle, but the plough when they are setting; 40 days they stay away from heaven; when Arcturus ascends from the sea and, rising in the evening, remain visible for the entire night, the grapes must be pruned; but when Orion and Sirius come in the middle of heaven and the rosy fingered Eos sees Arcturus, the grapes must be picked; when the Pleiades, the Hyades, and Orion are setting, then mind the plough; when the Pleiades, fleeing Orion, plunge into the dark sea, storms may be expected; 50 days after the sun's turning is the right time for man to navigate; when Orion appears, Demeter's gift has to be brought to the well-smoothed threshing floor.For many hundreds of years astronomers would write works on such rising and setting of constellations indicating that the type of advice given by Hesiad continued to be used.An early time scale based on 12 months of 30 days did not work well since the moon rapidly gets out of phase with a 30 day month. So by 600 BC this had bee n replaced by a year of 6 'full' months of 30 days and 6 'empty' months of 29 days. This improvement in keeping the moon in phase with the month had the unfortunate effect of taking the year even further out of phase with the period of the recurring seasons. About the same time as Thales was making the first steps in philosophy, Solon, a statesman in Athens who became known as one of the Seven Wise Men of Greece, introduced an improved calendar.Solon's calendar was based on a two yearly cycle. There were 13 months of 30 days and 12 months of 29 days in each period of two years so this gave a year of about 369 days and a month of 291/2days. However, the Greeks relied mainly on the moon as their time-keeper and frequent adjustments to the calendar were necessary to keep it in phase with the moon and the seasons. Astronomy was clearly a subject of major practical importance in sorting out the mess of these calendars and so observations began to be made to enable better schemes to be devised.Pythagoras, around 500 BC, made a number of important advances in astronomy. He recognised that the earth was a sphere, probably more because he believed that a sphere was the most perfect shape than for genuine scientific reasons. He also recognised that the orbit of the Moon was inclined to the equator of the Earth and he was one of the first to realise that V enus as an evening star was the same planet as V enus as a morning star. There is a pleasing appeal to observational evidence in these discoveries, but Pythagoras had a philosophy based on mathematical 'perfection' which tended to work against a proper scientific approach. On the other side there is an important idea in the Pythagorean philosophy which had a lasting impact, namely the idea that all complex phenomena must reduce to simple ones. One should not underestimate the importance of this idea which has proved so powerful throughout the development of science, being a fundamental driving force to the great scientists such as Newton and particularly Einstein.Around 450 BC Oenopides is said to have discovered the ecliptic made an angle of 24° with the equator, which was accepted in Greece until refined by Eratosthenes in around 250 BC. Some scholars accept that he discovered that the ecliptic was at an angle but doubt that he measured the angle. Whether he learnt of the 12 signs of the zodiac from scholars in Mesopotamia or whether his discoveries were independent Greek discoveries is unknown. Oenopides is also credited with suggesting a calendar involving a 59 year cycle with 730 months. Other schemes proposed were 8 year cycles, with extra months in three of the eight years and there is evidence that this scheme was adopted.About the same time as Oenopides proposed his 59 year cycle, Philolaus who was a Pythagorean, also proposed a 59 year cycle based on 729 months. This seemed to owe more to the numerology of the Pythagoreans than to astronomy since 729 is 272, 27 being the Pythagorean number for the moon, while it is also 93, 9 being the Pythagorean number associated with the earth. Philolaus is also famed as the first person who we know to propose that the earth moves. He did not have it orbiting the sun, however, but rather all the heavenly bodies went in circles round a central fire which one could never see since there was a counter earth between the earth and the fire. This model, certainly not suggested by any observational evidence, is more likely to have been proposed so that there were 10 heavenly bodies, for 10 was the most perfect of all numbers to the Pythagoreans.Meton, in 432 BC, introduced a calendar based on a 19 year cycle but again this is similar to one devised in Mesopotamia some years earlier. Meton worked in Athens with another astronomer Euctemon, and they made a series of observations of the solstices (the points at which the sun is at greatest distance from the equator) in order to determine the length of the tropical year. Again we do not know if the 19 year cycle was an independent discovery or whether Greek advances were still based on earlier advances in Mesopotamia. Meton's calendar never seems to have been adopted in practice but his observations proved extremely useful to later Greek astronomers such as Hipparchus and Ptolemy.That Meton was famous and widely known is seen from the play Birds written by Aristopenes in about 414 BC. Two characters are speaking, one is Meton [see D Barrett (trs.), Aristophanes, Birds (London, 1978)]:-Meton: I propose to survey the air for you: it will have to be marked out in acres. Peisthetaerus: Good lord, who do you think you are?Meton: Who am I? Why Meton. THE Meton. Famous throughout the Hellenic world - you must have heard of my hydraulic clock at Colonus?Meton and Euctemon are associated with another important astronomical invention of the time, namely a parapegma. A parapegma was a stone tablet with movable pegs and an inscription to indicate the approximate correspondence between, for example, the rising of a particular star and the civil date. Because the calendar had to be changed regularly to keep the civil calendar in phase with the astronomical one, the parapegma had movable pegs which could be adjusted as necessary. A parapegma soon also contained meteorological forecasts associated with the risings and settings of the stars and not only were stone parapegma constructed but also ones on papyri.Meton and Euctemon are usually acknowledged as the inventors of parapegmata and certainly many later astronomers compiled the data nessary for their construction. There is evidence for other observational work being undertaken around this time, for Vitruvius claims that Democritus of Abdera, famed for his atomic theory, devised a star catalogue. We have no knowledge of the form this catalogue took but Democritus may well have described the major constellations in some way.The beginning of the 4th century BC was the time that Plato began his teachings and his writing was to have a major influence of Greek thought. As far as astronomy is concerned Plato had a negative effect, for although he mentions the topic many times, no dialogue is devoted to astronomy. Worse still, Plato did not believe in astronomy as a practical subject, and condemned as lowering the spirit the actual observation of the heavenly bodies. Plato only believed in astronomy to the extent that it encouraged the study of mathematics and suggested beautiful geometrical theories.Perhaps we should digress for a moment to think about how the ideas of philosophy which were being developed by Plato and others affected the development of astronomy. Neugebauer [6] feels that philosophy had a detrimental affect:-I see no need for considering Greek philosophy as an early stage in the development of science ... One need only read the gibberish of Proclus's introduction to his huge commentary on Book I of Euclid's Elements to get a vivid picture of what would have become of science in the hands of philosophers. The real "Greek miracle" is the fact that a scientific methodology was developed, and survived, in spite of a widely admired dogmatic philosophy.Although there is some truth in what Neugebauer writes here, I [EFR] feel that he has overstated his case. It is true that philosophers came up with ideas about the universe which were not based on what we would call today the scientific method. However, the very fact that theories were proposed which could be shown to be false by making observations, must have provided a climate where the scientific approach could show its strength. Also the fact the philosophy taught that one should question all things, even "obvious" truths, was highly beneficial. Another important philosophical idea which had important consequences from the time of Pythagoras, and was emphasised by Plato, was that complex phenomena must be consequences of basic simple phenomena. As Theon of Smyrna expressed it, writing in the first century AD:-The changing aspects of the revolution of the planets is because, being fixed in their own circles or in their own shperes whose movements they follow, they are carried across the zodiac, just as Pythagoras had first understood it, by a regulated simple and equal revolution but which results by combination in a movement that appears variable and unequal.This led Theon to write:-It is natural and necessary that all the heavenly bodies have a uniform and regular movement.Perhaps the most telling argument against the above claim by Neugebauer is that our present idea of space-time, as developed from Einstein's theory of relativity, was suggested more by the basic philosophy of simplicity than by experimental evidence. The advances made not long after the time of Plato by Eudoxus, incorporating theidea of basic simplicity as expressed in Pythagorean and Platonic philosophy, were made by an outstanding mathematician and astronomer. In fact Eudoxus marks the beginning of a new phase in Greek astronomy and must figure as one of a small number of remarkable innovators in astronomical thought. Eudoxus was the first to propose a model whereby the apparently complex motions of the heavenly bodies did indeed result from simple circular motion. He built an observatory on Cnidus and from there he observed the star Canopus. The star Canopus played an important role in early astronomy, for it is seen to set and rise in Cnidus yet one does no have to go much further north from there before it can never be seen. The observations made at Eudoxus's observatory in Cnidus, as well as those made at an observatory near Heliopolis, formed the basis of a book concerning the rising and setting of the constellations. Eudoxus, another who followed Pythagorean doctrines, proposed a beautiful mathematical theory of concentric spheres to describe the motion of the heavenly bodies. It is clear that Eudoxus thought of this as a mathematical theory, and did not believe in the spheres as physical objects.Although a beautiful mathematical theory, Eudoxus's model would not have stood the test of the simplest of observational data. Callippus, who was a pupil of Polemarchus himself a pupil of Eudoxus, refined this system as presented by Eudoxus. The reason that we have so much information about the spheres of Eudoxus and Callippus is that Aristotle accepted the theory, not not as a mathematical model as originally proposed, but rather as spheres which have physical reality. He discussed the interactions of one sphere on another, but there is no way that he could have had enough understanding of physics to get anywhere near describing the effects of such an interaction. Although in many areas Aristotle advocated a modern scientific approach and he collected data in a scientific way, this was unfortunately not the case in astronomy. As Berry writes [2]:- There are also in Aristotle's writings a number of astronomical speculations, founded on no solid evidence and of little value ... his original contributions are not comparable with his contributions to the mental and moral sciences, but are inferior in value to his work in other natural sciences ...As Berry goes on to say, this was very unfortunate for astronomy since the influence of the writings of Aristotle had an authority for many centuries which meant that astronomers had a harder battle than they might otherwise have had in getting the truth accepted.The next development which was absolutely necessary for progress in astronomy took place in geometry. Spherical geometry was developed by a number of mathematicians with an important text being written by Autolycus in Athens around 330 BC. Some claim that Autolycus based his work on spherical geometry On the Moving Sphere on an earlier work by Eudoxus. Whether or not this is the case there is no doubt that Autolycus was strongly influenced by the views of Eudoxus on astronomy. Like so many astronomers, Autolycus wrote a work On Risings and Settings which is a book on observational astronomy.After Autolycus the main place for major developments in astronomy seemed to move to Alexandria. There Euclid worked and wrote on geometry in general but also making an important contribution to spherical geometry. Euclid also wrotePhaenomena which is an elementary introduction to mathematical astronomy and gives results on the times stars in certain positions will rise and set.Aristarchus, Timocharis and Aristyllus were three astronomers who all worked at Alexandria and their lives certainly overlapped. Aristyllus was a pupil of Timocharis and in Maeyama [23] analyses 18 of their observations and shows that Timocharis observed around 290 BC while Aristyllus observed a generation later around 260 BC. He also reports an astounding accuracy of 5' for Aristyllus' observations. Maeyama writes [23]:- The order of accuracy is an essential measure for the development of natural sciences. accuracy is in fact more than the mere operation of measuring. Accuracy increases only by virtue of active measuring. There cannot exist a high order of observational accuracy which is not connected with a high order of observations. Hence my assumption is that there must have been abundant accurate observations of the fixed stars made at least at the epochs 300 BC - 250 BC in Alexandria. They must have disappeared in the fires which frequently raged there. Maeyama also points out that this is the period when the coordinate systems for giving stellar positions originated. Both the equatorial and the ecliptic systems appear at this time. But why were these observations being made? This is a difficult question to answer for on the face of it there seems little point in the astronomers of Alexandria striving for observational accuracy at this time. In [34] van der Waerden makes an interesting suggestion related to the other important astronomer who worked in Alexandria around this time, namely Aristarchus.We know that Aristarchus measured the ratio of the distances to the moon and to the sun and, although his methods could never yield accurate results, they did show that the sun was much further from the earth than was the moon. His results also showed that the sun was much larger than the earth, although again his measurements were very inaccurate. Some historians believe that this knowledge that the sun was the largest of the three bodies, earth, moon and sun, led him to propose his heliocentric theory. Certainly it is for this theory, as reported by Archimedes, that Aristarchus has achieved fame. His sun-centred universe found little favour with the Greeks, however, who continued to develop more and more sophisticated models based on an earth centred universe.Now Goldstein and Bowen in [16] attempt to answer the question of why Timocharis and Aristyllus made their accurate observations. These authors do not find a clear purpose for the observations, such as the marking of a globe. However van der Waerden in [34] suggests that the observations were made to determine the constants in the heliocentric theory of Aristarchus. Although this theory has strong attractions, and makes one want to believe in it, all the evidence suggests that Timocharis certainly began his observations some time before Aristarchus proposed his heliocentric universe.Goldstein and Bowen in [16] make other interesting suggestions. They believe that the observations of Timocharis and Aristyllus recorded the distance from the pole, and the distances between stars. They argued that the observations were made by means of an instrument similar to Heron's dioptra. These are interesting observations since the work of Timocharis and Aristyllus strongly influenced the most important of all of theGreek astronomers, namely Hipparchus, who made his major contribution about 100 years later. During these 100 years, however, there were a number of advances. Archimedes measured the apparent diameter of the sun and also is said to have designed a planetarium. Eratosthenes made important measurements of the size of the earth, accurately measured the angle of the ecliptic and improved the calendar. Apollonius used his geometric skills to mathematically develop the epicycle theory which would reach its full importance in the work of Ptolemy.The contributions of Hipparchus are the most important of all the ancient astronomers and it is fair to say that he made the most important contribution before that of Copernicus in the early sixteenth century. As Berry writes in [2]:- An immense advance in astronomy was made by Hipparchus, whom all competent critics have agreed to rank far above any other astronomers of the ancient world, and who must stand side by side with the greatest astronomers of all time.It is Hipparchus's approach to science that ranks him far above other ancient astronomers. His approach, based on data from accurate observations, is essentially modern in that he collected his data and then formed his theories to fit the observed facts. Most telling regarding his understanding of the scientific method is the fact that he proposed a theory of the motion of the sun and the moon yet he was not prepared to propose such a theory for the planets. He realised that his data was not sufficiently good or sufficiently plentiful to allow him to base a theory on it. However, he made observations to help his successors to develop such a theory. Delambre, in his famous work on the history of astronomy, writes:- When we consider all that Hipparchus invented or perfected, and reflect upon the number of his works and the mass of calculations which they imply, we must regard him as one of the most astonishing men of antiquity, and as the greatest of all in the sciences which are not purely speculative, and which require a combination of geometrical knowledge with a knowledge of phenomena, to be observed only by diligent attention and refined instruments. Although a great innovator, Hipparchus gained important understanding from the Babylonians. As Jones writes in [21]:- For Hipparchus, the availability of the Babylonian predictive methods was a boon.We will not describe the contributions of Hipparchus and Ptolemy in detail in this article since these are given fully in their biographies in our archive. Suffice to end this article with a quotation from [6]:- Alexandria in the second century AD saw the publication of Ptolemy's remarkable works, the 'Almagest' and the 'Handy Tables', the 'Geography', the 'Tetrabiblos', the 'Optics', the 'Harmonics', treatises on logic, on sundials, on stereographic projection, all masterfully written, products of one of the greatest scientific minds of all times. The eminence of these works, in particular the 'Almagest', had been evident already to Ptolemy's contemporaries. this caused an almost total obliteration of the prehistory of the Ptolemaic astronomy.Ptolemy had no successor. What is extant from the later Roman times is rather sad.....3.Mathematical discovery of planetsThe first planet to be discovered was Uranus by William and Caroline Herschel on 13 March 1781. It was discovered by the fact that it showed a disk when viewed through even a fairly low powered telescope. The only other planets which have been。

astronomy 天文学astronomical 天文的astronomical observatory 天文台astronomer 天文学家astrophysics 天文物理学astrology 占星学pseudoscience 伪科学cosmos 宇宙cosmology 宇宙学infinite 无限的cosmic 宇宙的cosmic radiation 宇宙辐射cosmic rays 宇宙射线celestial 天的celestial body 天体celestial map 天体图celestial sphere 天球dwarf 矮星quasar 类星体，类星射电源constellation 星座galaxy 新河系cluster 星团solar system 太阳系solar corona 日冕solar eclipse 日食solar radiation 太阳辐射planet 行星planetoid 小行星asteroid revolve 旋转，绕转twinkle 闪烁naked eye 肉眼Mercury 水星V enus 金星Earth 地球Mars 火星Jupiter 木星Saturn 土星Uranus 天王星Neptune 海王星Pluto 冥王星orbit 轨道spin 旋转satellite 卫星lunar 月球的meteor 流星meteor shower流星雨meteoroid 流星体meteorite 陨石comet 彗星space 太空，外层空间spacecraft 宇宙飞船spaceman 宇航员，航天员space suit 宇航服，航天服space shuttle 航天飞机space telescope空间望远镜astronaut 宇航员star 恒星stellar 恒星的intergalactic 星系间的interstellar 恒星间的interplanetary 行星间的asteroid 小行星nebula 星云space debris 太空垃圾ammonia 氨corona 日冕chromosphere 色球photosphere 色球层convection 传送，传导；zone 对流层vacuum 真空infrared红外线的；红外线ray 红外线chondrite 球粒陨石meteorite 陨石absolute magnitude 绝对量级radiation 辐射emission 发射，散发high-resolution 高清楚度interferometer 干扰仪methane甲烷，沼气宇宙和另外两个是包含与被包含关系，银河系和河外星系是并列关系。

托福听力天文地理篇(astronomy&geology)Hello, 相信不少备考托福的同学都知道托福听力会考到天文题，今天就为大家来解读一下学科背景专项和套题模考强化段之天文地理篇(astronomy& geology)托福听力天文地理篇(astronomy& geology)首先，小编先来讲一下文章题材，从TPO11-34，我们可以发现一般天文类的文章主要分为两大类，一类是解释说明文(eg现象，物质，新的发现等)，还有一类就是议论文(eg不同观点或者新老观点对比等) 那对于第一类说明文，文章内容主要是现象的特点特征，产生这种现象的原因，科学家们是如何发现现象或探测的方法，以及在文末可能会出现Prof对前文的观点或者方法的评价。

第二类议论文，文章内容主要是新老观点对比，或是不同学术者提出自己的观点，那么那些支持不同观点的论据就是听力中需要记录的要点，同样在文末可能会出现Prof对于这些观点的评价。

天文学类的文章很容易出现新的词或者信息，通常在这些词和信息后面都会有解释甚至是停顿，这时候童鞋们就需要打起十二分精神仔细听，因为考点很有可能就会出现。

以上这些都是童鞋们需要记录的要点。

对于这类的题材问题主要是主旨题，细节题(特征，因果，产生什么作用等)，语境语义题(Prof的观点，或句子文中的含义)下面是小编为大家整理的TPO里面关于天文学一类的素材，按照不同的难易程度来分，11-19可以作为背景专项训练，20-34可以作为模考强化训练，其中25之后和现在考试难度相似Difficult TPO 13 L4, TPO 19 L2, TPO 21 L1, TPO 22 L2, TPO 24 L4, TPO 30 L3Medium TPO 14 L3, TPO 18 L1, TPO 26 L3HOHO~~现在是不是对天文的概念要清晰一点了，接下来小编再和童鞋们分享一下地理篇。

相对于天文学来说，地理学主要是以说明文为主(eg 说明一种现象、板块移动说、自然环境生态的形成等)同样的这些说明文就是对一种现象和自然生态的解释说明，包括了形成过程，特征特点，产生的原因，科学家们如何研究得出结论(eg 用什么仪器设备，探测什么物质的含量等)那文末就会是Prof对前面观点和结论的评价或者是总结。

Astronomers said on Wednesday that they had discovered a lost generation of monster stars that ushered light into the universe after the Big Bang and jump-started the creation of the elements needed for planets and life before disappearingforever. 天文学家在周三表示，他们发现了失踪的一代巨型恒星，是它们在宇宙大爆炸之后将光照入宇宙，并在永远消失之前，瞬间启动了星球及生命所需要的所有元素的创造。

Modern-day stars like our sun have a healthy mix of heavy elements, known as metals, but in the aftermath of the Big Bang only hydrogen, helium and small traces of lithium were available to make the first stars. 太阳等现代恒星拥有大量重元素，也就是金属元素，但在宇宙大爆炸之后，构成第一代恒星的元素只有氢、氦和少量锂。

Such stars could have been hundreds or thousands of times as massive as the sun, according to calculations, burning brightly and dying quickly, only 200 million years after the universe began. Their explosions would have spewed into space the elements that started the chain of thermonuclear reactions by which subsequent generations of stars have gradually enriched the cosmos with elements like oxygen, carbon and iron. 根据计算，此类恒星的质量可能是太阳质量的数百或数千倍，这些形成于宇宙大爆炸后2亿年的恒星猛烈燃烧，迅速消失。

托福听力天文学背景知识英文回答：As an astronomy enthusiast, I have always been fascinated by the wonders of the universe and the vastnessof space. My interest in astronomy began when I was a child.I remember looking up at the night sky and being amazed by the countless stars twinkling above me. I would spend hours reading books about space and learning about the different celestial bodies.One of the most interesting aspects of astronomy is the study of galaxies. Galaxies are massive systems of stars, gas, and dust that are held together by gravity. There are billions of galaxies in the universe, each containingbillions of stars. The Milky Way, which is the galaxy that our solar system is a part of, is just one of many galaxies in the universe.Studying galaxies can provide valuable insights intothe formation and evolution of the universe. Astronomers use various techniques to study galaxies, such as observing their light emissions, measuring their distances, and analyzing their chemical compositions. By studying the properties of galaxies, astronomers can learn about the processes that shape the universe.For example, the study of galaxies has led to the discovery of dark matter and dark energy. Dark matter is a mysterious substance that cannot be directly observed, but its presence can be inferred from its gravitational effects on visible matter. Dark energy, on the other hand, is an even more mysterious force that is responsible for the accelerating expansion of the universe. These discoveries have revolutionized our understanding of the cosmos.中文回答：作为一个天文学爱好者，我一直对宇宙的奇迹和广阔的空间深感着迷。

经过上文的阅读，是否意犹未尽呢？环球托福为备考托福听力的考友们带来托福TPO听力文本翻译Lecture1Astronomy（下），帮助大家复习托福听力以及分析听力文章的重点通常出现在哪些关键词后。

下面，请看环球托福分享的托福TPO听力文本：Geocentric&Heliocentric theoryFor example, Greek astronomers made excellent, very accurate observations of the movements of the planets, but the observations revealed a bit of a problem. The geocentric theory said that the planets would move around the Earth in one direction. However, astronomers noticed that at times, several planets seem to stop moving in one direction and start moving backward in their orbits around the Earth, and they came up with a theory that these planets themselves moved in smaller circles called epicycles as they travelled around the Earth. Here’s a picture of what they imagined. You see how this epicycle theory could account for the seemingly backward motion of the planet. Of course, today we know that this appearance of backward motion is caused by the fact that Earth, as well as other planets, all move in their own orbits around the Sun, and the relative movements of the planets with respect to each other can get quite complex.托福TPO听力文本翻译例如，希腊天文学家曾经对行星的运动进行过出色而准确的观测，但结果却颇为尴尬。

今天，环球托福为备考托福听力的考友们带来托福TPO听力文本翻译Lecture1Astronomy （上），帮助大家复习托福听力以及分析听力文章的重点通常出现在哪些关键词后。

下面，请看环球托福分享的托福TPO听力文本：Computer Science (Software Development)Narrator Listen to part of a lecture in a Computer Science class. The professor is discussing software engineering.Professor We’ve been talking about the software development cycle, and today I’d like to move on to the next stage of that cycle-testing, and why findingbugs during testing is actually a great thing. Eh...eh... the quality of the software product often relies heavily on how well it’s been tested. Liz?托福TPO听力文本翻译我们已经讨论过了软件开发周期，今天我会继续讲周期测试的下一个阶段，以及为什么寻找“虫子”非常重要。

呃……软件产品的质量经常非常依赖测试的好坏。

Liz？Student Um... just a quick thing. Bugs are the word for problems in the program code, right?ProfessorYeah, in code or in a computer itself. There is a bit of a story behind that term. Um... back in the 1940s, when the computer industry was just starting, agroup of computer scientists was working late one night, and there was a problem in one of the computers’circuits1. When they examined it, they found a five-centimeter long moth caught in there. Once they debugged the computer, it worked just fine. And ever since then, all kinds of computer problems have been known as bugs.托福TPO听力文本翻译对，就是指代码或者计算机本身中的问题。