為紀(jì)念伽利略首次使用望遠(yuǎn)鏡進(jìn)行天文觀測(cè)400周年，在國(guó)際天文學(xué)聯(lián)合會(huì)和聯(lián)合國(guó)教科文組織的共同倡議下，聯(lián)合國(guó)大會(huì)將2009年正式確定為國(guó)際天文年，并將其主題定為“探索我們的宇宙”。即使你一點(diǎn)都不喜歡讓人費(fèi)解的天文學(xué)，也會(huì)偶爾仰望星空吧，畢竟那里有太多的神秘、太多的遐想。本次專題分上下兩輯，為大家?guī)?3個(gè)天文史上最偉大的發(fā)現(xiàn)。噢，別太擔(dān)心，主持人很擅長(zhǎng)以簡(jiǎn)單的語句解釋深?yuàn)W的天文理論，保證所有小盆友都能看得明白哦!快來參加這次發(fā)現(xiàn)之旅吧!By the way，記得關(guān)注下期發(fā)現(xiàn)哦!

For most of human history， the only light we knew came from the sky， by day the sun， by night an uncountable

number of stars. From the beginning， our ancestors

believed that the sun and the stars were heavenly[神圣的]，

out of this world. And they were right. We’ve been watching the sky for thousands of years， but until

recently， we couldn’t see well enough to understand our connection to the cosmos. But now our astronomical

vision has sharpened. We can see farther and clearer. We can observe objects that are invisible to human eyes. Our increasingly improving vision has allowed us to make great discoveries， revealing an astonishing

and wonderful universe. What follows are 13 of the greatest discoveries in astronomy.

The Planets Move

Discoverer: Greeks

Our first great discovery happened over centuries as the first humans looked carefully at the sky in places like this， the empty cloudless deserts of the American southwest， the Middle East， Africa and South America. Of these ancient astronomers the most important were the

Mesopotamians注1. They considered the objects in the sky gods， and built giant towers so they could record the rising and setting of the sun， the moon and the stars. For more than 1，000 years， they used clay tablets[小平板] to

record what they saw.

After the Mesopotamians made the first records， it was the Greeks who took the next step.

Owen Gingerich (Astronomy professor): Some of the Greek astronomers made a field trip[實(shí)際考察旅行] out to Mesopotamia to find out what had been going on there. And they seem to have brought back some systematic records， so that ultimately， it gave the basis for making a mathematical theory of the motion of the planets.

From their observations， the Greeks developed a

vision of the solar system that would stand for some 2，000 years – that the planets move， revolving[繞轉(zhuǎn)] around the Earth. It would take our next great discovery to set the

record straight[澄清問題].

The Earth Moves

Discoverer: Nicolaus Copernicus

As a young man， Copernicus had studied the heavens and found that the Greek’s earth-centered system failed when it came to predicting planetary[行星的] motion. He

began to wonder if the Earth itself moved.

Copernicus realized that the movements of the

planets were better explained if the sun were at the centre of the solar system and the Earth circled it like an ordinary planet. It was a revolutionary insight.

Nye: This idea， this…this book注2， changed the world.

Gingerich: Yes， because it made the Earth a planet and it fixed the sun in the centre. If you don’t have that

blueprint， you don’t march ahead to the physics…the physics of the cosmos.

Planetary Orbits Are Elliptical [橢圓的]

Discoverer: Johannes Kepler

Everyone from the Greeks to Copernicus assumed the orbits of the planets had to be circular[圓形的]， but in 1571 German mathematician Johannes Kepler shattered[使粉碎] that assumption with our next great discovery.

Lacking calculus[微積分]， Kepler improvised[即席創(chuàng)作]

ways to compute[計(jì)算] the circular orbit of Mars. The work was tedious[冗長(zhǎng)乏味的]. Kepler wrote that he was， “almost

driven to madness considering and calculating the

matter.” His calculations began to reveal that the

accepted notion of planets moving in circles simply did not work. Then a new idea came to him.

Gingerich: Kepler

realized somehow the sun had to be driving the planets in some way that he didn’t fully understand， and to get a

self-consistent[首尾一致的]

picture， he found that an ellipse was the path rather than a circle.

With this breakthrough， Kepler had devised the first method for accurately predicting the movement of the planets and stars across the sky.

Gingerich: When his tables predicted the planet Mercury to pass across the front of the Sun， and nobody else’s tables were close， that was dramatic proof of the accuracy of his astronomy that linked the motions of the planets solidly to the sun. This was a very important point to help stress the idea that the Copernican sun-centered system really had physical significance.

Despite the success of Kepler’s theory， many

remained skeptical[懷疑的] that the sun could be the center of the solar system. But the final nail in that

coffin[一錘定音的證據(jù)] was about to be driven home[把……講透徹] by a man who， like Kepler， preferred to use observational evidence to form his theories. And that man was Galileo Galilei.

Jupiter Has Moons

Discoverer: Galileo Galilei

The year is 1609， and Galileo is fascinated with a new invention called a telescope. Galileo turned his

telescope skyward[朝天空] and was the first to see the mountains on the moon and the star clusters[星團(tuán)] of the Milky Way. Then an extraordinary sight， a group of four small， bright stars arranged around the planet Jupiter. This was the moment of discovery. Galileo realized that the stars were actually four moons orbiting Jupiter.

Here was proof that Copernicus was right about the structure of the solar system. If moons could orbit Jupiter， then the Earth could orbit the sun. And Galileo’s discovery demonstrated[證明] that knowledge in astronomy can only be advanced by actual observation. A theory can only be viable[可行的] when it’s supported by the facts， just like our next great discovery.

Halley’s Comet

Discoverer: Edmund Halley

For centuries， comets had been considered

harbingers[前兆] of evil. By the end of the Middle Ages， a comet’s appearance invoked[引起] fear and terror. But

Renaissance[文藝復(fù)興(的)]

scientist Edmund Halley， like Galileo， was interested in facts not superstition[迷信].

In 1695， he began searching for records of ancient and recent comet sightings. He found 24 comets whose passage across the sky had been recorded with enough

detail to allow him to roughly plot their orbits. To his surprise， he found that three of the comets seemed to follow the same approximate[近似的]

orbit， circling the sun every 76 years. Halley was so certain of the comet’s orbit that he made a bold prediction. He said the comet would return in the year 1758.

Gingerich: And guess what， the comet came

back.

Unfortunately Halley was no longer alive to savor[品嘗] his discovery. Since then Halley’s Comet， as it’s known， has been greeted three more times by excited sky watchers across the globe.

No longer a harbinger of evil， Halley’s Comet became a milestone discovery in the history of astronomy，

replacing a superstitious belief with a rational[理性的]

scientific understanding of the physical universe.

Milky Way Is a Disk of Stars

Discoverer: William Herschel

In the 18th century， William Herschel was a classically-trained musician， whose love of astronomy led him to give up music and turn his attention to the heavens， thus setting the stage for our next great discovery.

Gingerich: When he discovered the price of a

refracting telescope[折射望遠(yuǎn)鏡]， which was beyond his means[超出某人的財(cái)力]， he decided to make his own， and he became the most fabulous and successful telescope builder of that period.

He used his telescopes to methodically[有條理地]

survey the sky， cataloguing[為……編目] what he saw.

Gingerich: As he was searching the sky， he came across an object that looked a little bit different – turned out to be a new planet. That was the next planet

beyond Saturn， the planet Uranus.

Uranus was the first new planet to be identified in more than 3500 years.

But finding a new planet was nothing compared to Herschel’s larger goal. He built a powerful 20-foot telescope， then divided the sky into equal sections and began to systematically count the stars in each field. It was a painstaking[不辭勞苦的]， monumental[重要的] task. Slowly Herschel’s star count[恒星計(jì)數(shù)] began to reveal something extraordinary. The Milky Way was much larger than anyone knew. It was a gigantic[巨大的] disk of stars. Some of its fields were jam-packed[擠的]. One showed more than a quarter of a million stars alone. Other fields farther away were practically empty. Herschel’s discovery was a revelation[啟示].

Gingerich: What Herschel was seeing was， oh， a small range[區(qū)域] like this注3， maybe that big…So it was really a small part of the entire Milky Way.

But even that small part significantly changed the study of astronomy. Herschel’s discovery

revealed that our solar system was just an island in a deep and expansive universe.

在人類史的很長(zhǎng)一段時(shí)間，我們僅知的光亮來自天空。白天是太陽，夜晚則是不計(jì)其數(shù)的繁星。從一開始，我們的祖先便篤信太陽星辰都是神圣的，不屬于凡塵世界。的確如此。人類觀察星空持續(xù)千年，然而直至近代，我們的觀察并不足以讓我們很好地了解人類自身與宇宙之間的聯(lián)系。如今，隨著天文視野變得更為敏銳，我們能觀察得更遠(yuǎn)、更清晰，也能觀察到肉眼無法辨識(shí)的星體。不斷擴(kuò)大的視野使我們?nèi)〉帽姸嘀卮蟀l(fā)現(xiàn)，揭開了宇宙奧妙神奇的面紗。接下來，我將為大家?guī)?3個(gè)天文史上最偉大的

發(fā)現(xiàn)。

地心天動(dòng)說

發(fā)現(xiàn)者:希臘人

(天文史上)第一個(gè)偉大的發(fā)現(xiàn)歷時(shí)數(shù)百年。當(dāng)時(shí)，人類在一些空曠無云的地方——美國(guó)西南、中東、非洲及南美等地的沙漠首次仔細(xì)觀察星空。在這些古代天文學(xué)家中，最為重要的是美索不達(dá)米亞人。他們將天空的星體視為神明，建造高塔以觀察記錄日月星辰的升降運(yùn)行。一千多年來，他們使用泥板記錄觀察結(jié)果。

美索不達(dá)米亞人寫下第一批天文記錄之后，希臘人對(duì)其予以繼承

發(fā)展。

歐文·金格里茲(天文學(xué)教授):一些希臘天文學(xué)家到美索不達(dá)米亞做實(shí)地考察，想知道當(dāng)?shù)厝嗽谘芯渴裁?。他們帶回來一些系統(tǒng)的記錄，這些記錄最終為他們提出行星運(yùn)動(dòng)的數(shù)學(xué)理論奠定了

基礎(chǔ)。

希臘人從觀察中發(fā)展出一套兩千多年來屹立不倒的太陽系理論。這個(gè)理論就是“地心天動(dòng)說”——星體圍繞地球運(yùn)轉(zhuǎn)。直到我們得出下一個(gè)偉大發(fā)現(xiàn)，這個(gè)理論才得到更正。

日心地動(dòng)說

發(fā)現(xiàn)者:尼古拉斯·哥白尼

年紀(jì)尚輕時(shí)，哥白尼就已經(jīng)開始研究星空。他發(fā)現(xiàn)古希臘的地心天動(dòng)說無法正確預(yù)測(cè)星體的運(yùn)行。他開始懷疑地球本身是否也在運(yùn)轉(zhuǎn)。

哥白尼發(fā)現(xiàn)，只有當(dāng)太陽成為太陽系中心，而地球作為普通行星圍繞其運(yùn)行，這個(gè)理論才能更好地解釋星體的運(yùn)轉(zhuǎn)。這是一項(xiàng)革命性的見解。

尼爾:這個(gè)觀點(diǎn)……這本書改變了世界。

金格里茲:是的，因?yàn)樗鼘⒌厍蛞暈橐粋€(gè)行星，太陽則為(太陽系的)中心。如果你沒有這樣的遠(yuǎn)見，就無法發(fā)展出物理學(xué)……宇宙物理學(xué)的理論。

橢圓軌道定律

發(fā)現(xiàn)者:約翰尼斯·開普勒

從古希臘人到哥白尼，所有人都認(rèn)為行星軌道是正圓形。但是在1571年，德國(guó)數(shù)學(xué)家約翰尼斯·開普勒以我們的下一個(gè)偉大新發(fā)現(xiàn)推翻了這個(gè)猜想。

在沒有微積分的情況下，開普勒靈機(jī)一動(dòng)，用新的方法變換著計(jì)算火星的運(yùn)行軌道。這是一項(xiàng)相當(dāng)枯燥的工作。開普勒曾寫道，自己“嘗試過無數(shù)不同的推理和計(jì)算，幾近瘋狂”。他的計(jì)算結(jié)果顯示，我們一直習(xí)以為然的“行星依照正圓軌道運(yùn)行”這個(gè)觀點(diǎn)根本不成立。于是他產(chǎn)生了一個(gè)新的想法。

金格里茲:開普勒認(rèn)為太陽以某種他不太理解的方式驅(qū)使行星繞其運(yùn)行。為了讓自己的推論前后一致，他發(fā)現(xiàn)(火星繞行軌道)是一個(gè)橢圓而不是正圓。

在這個(gè)突破性理論的幫助下，開普勒制定出第一個(gè)能準(zhǔn)確預(yù)測(cè)星體在天空中運(yùn)行的軌跡的方法。

金格里茲:當(dāng)時(shí)，他的法則準(zhǔn)確預(yù)測(cè)到“水星凌日”，其他人的法則無一能及，這有力地證明了其天文學(xué)理論的精確性，也證明了行星運(yùn)行與太陽有密切關(guān)系。同時(shí)，它進(jìn)一步證明哥白尼日心說確實(shí)具有重大意義。

盡管開普勒的理論驗(yàn)證成功，但仍有許多人對(duì)“太陽是太陽系的中心”一說存有懷疑。最后的鐵證來自一個(gè)人，他與開普勒一樣，更喜歡通過實(shí)際觀測(cè)證據(jù)得出理論，這個(gè)人就是伽利略·

伽利萊伊。

木星有衛(wèi)星

發(fā)現(xiàn)者:伽利略·伽利萊伊

時(shí)間來到1609年，伽利略沉迷于一種叫“望遠(yuǎn)鏡”的新發(fā)明之中。伽利略用自制的望遠(yuǎn)鏡觀測(cè)天體，并且首次觀察到月球表面的山丘以及銀河中的無數(shù)星團(tuán)。隨后，他發(fā)現(xiàn)了一個(gè)很不尋常的景象:木星的四周圍繞著四顆閃亮的小星星。這是歷史性的發(fā)現(xiàn)。伽利略發(fā)現(xiàn)，那四顆星星其實(shí)是繞行木星的衛(wèi)星。

這個(gè)發(fā)現(xiàn)也證明了哥白尼太陽系架構(gòu)理論的正確性。如果衛(wèi)星能圍繞木星運(yùn)行，那么地球也可以圍繞太陽運(yùn)行。伽利略的發(fā)現(xiàn)還證明了一點(diǎn):只有實(shí)際觀測(cè)才能讓天文新知得到進(jìn)一步發(fā)展;只有得到事實(shí)作證，理論才得以生存。下一個(gè)偉大發(fā)現(xiàn)亦是如此。

哈雷彗星

發(fā)現(xiàn)者:埃德蒙·哈雷

數(shù)百年來，彗星被視為不祥之兆。中世紀(jì)末期，彗星的每次出現(xiàn)都會(huì)引發(fā)極大的恐慌。但是，文藝復(fù)興時(shí)期科學(xué)家埃德蒙·哈雷跟伽利略一樣，相信事實(shí)而非迷信。

1695年，他開始尋找古今有關(guān)彗星的觀測(cè)記錄。他發(fā)現(xiàn)，記載中有24顆彗星的資料足以供其粗略地繪出運(yùn)行軌跡圖。令他驚訝的是，其中三顆彗星似乎遵循著相似的運(yùn)行軌跡，每隔76年繞行太陽一周。哈雷對(duì)這顆彗星的軌道信心十足，于是做出大膽預(yù)測(cè)。他斷言，這顆彗星將于1758年再次出現(xiàn)。

金格里茲:猜猜結(jié)果如何?彗星真的

回來了。

可惜哈雷未能親眼見證自己的預(yù)測(cè)成真。此后，這顆彗星被稱為“哈雷彗星”，全球興奮至極的觀星迷后來三次目睹了它的造訪。

哈雷彗星不再是不祥之兆的象征，它的發(fā)現(xiàn)成為天文史上一個(gè)重要的里程碑——傳統(tǒng)迷信被對(duì)真實(shí)宇宙的理性科學(xué)研究所取代。

銀河是盤狀星系

發(fā)現(xiàn)者:威廉·赫歇爾

威廉·赫歇爾是18世紀(jì)一位專業(yè)的古典音樂家。因?yàn)闊釔厶煳膶W(xué)，他放棄了音樂轉(zhuǎn)而研究起星象來，從而引出了下一個(gè)偉大的發(fā)現(xiàn)。

金格里茲:當(dāng)他發(fā)現(xiàn)自己買不起一具折射望遠(yuǎn)鏡時(shí)，赫歇爾決定自己動(dòng)手制作。后來，他成了當(dāng)時(shí)最杰出、最成功的望遠(yuǎn)鏡制作專家。

他用自制的望遠(yuǎn)鏡系統(tǒng)地觀測(cè)星空，并(將星象)進(jìn)行分類記錄。

金格里茲:在他觀測(cè)星空時(shí)，他發(fā)現(xiàn)了一顆不同尋常的星體，那是一顆新行星。它就是比土星更遙遠(yuǎn)的行星——

天王星。

天王星是3500多年間被發(fā)現(xiàn)的第一顆行星。

然而，與赫歇爾所追求的、更偉大的目標(biāo)相比，發(fā)現(xiàn)一顆新行星簡(jiǎn)直不值一提。他建造了一座高達(dá)20英尺(6米)的高倍望遠(yuǎn)鏡，將星空平均分為多個(gè)區(qū)域，系統(tǒng)性地記錄每一個(gè)星區(qū)里的星星。這是一項(xiàng)煞費(fèi)苦心，但也意義非凡的工程。慢慢地，赫歇爾的恒星計(jì)數(shù)顯示出一些不尋常的現(xiàn)象。銀河遠(yuǎn)比任何人想象的海要大。它是一個(gè)巨大的盤狀星云。某些區(qū)域擠滿了星星，其中一塊竟包含了25萬顆星星。但一些遙遠(yuǎn)的星區(qū)卻空空如也。赫歇爾的發(fā)現(xiàn)是一個(gè)新的啟示。

金格里茲:赫歇爾當(dāng)時(shí)觀測(cè)新的星空只有，呃，只有這么一點(diǎn)大的星區(qū)，大概只有這么大……那實(shí)際上只占了整個(gè)銀河系很小的一部分。

但是，即便是這么小的一部分，已經(jīng)給天文研究帶來重大影響。赫歇爾的發(fā)現(xiàn)證明，我們的太陽系只是寬廣且深遠(yuǎn)的宇宙中的一個(gè)小島。

注1:美索不達(dá)米亞平原的絕大部分位于今天的伊拉克境內(nèi)和敘利亞東北部，原為波斯灣的一部分，是位于底格里斯河及幼發(fā)拉底河之間的一片沖積平原。平原北部是亞述，南部則是古代四大文明的發(fā)源地之一——有高度發(fā)達(dá)的文明的巴比倫。

注2:“這本書”指的是哥白尼的著作《天體運(yùn)行論》(On the Revolutions of the Heavenly Spheres)。

注3:當(dāng)時(shí)金格里茲教授正拿著一個(gè)銀河的模型給主持人進(jìn)行解說。