我们住在叫银河的星系里 We live in a galaxy called the Milky Way.
这帝国由数千亿颗恒星组成 An empire with hundreds of billions of stars.
我们怎会在这里? How did we get here
我们的未来会怎样? and what's our future?
这些问题在各方面都牵涉星系 In every way, those questions involve galaxies.
在已知道的宇宙里有2000亿个星系 There are 200 billion galaxies in the known universe.
每个都独一无二, 巨大且处于动态 Each one unique, enormous and dynamic.
星系是狂暴的 Galaxies are violent.
它们在狂暴的历史里诞生 They were born in a violent history.
将会在狂暴中灭亡 They will die a violent death.
星系来自哪里? Where do galaxies come from?
怎样运作? How do they work?
它们的未来会怎样? What is their future?
怎样灭亡? And how will they die?
宇宙有道理 How the Universe Works
第1季第3集：星系
这是我们的星系, 银河 This is our galaxy, the Milky Way.
银河有大约120亿年历史 It's around 12 billion years old.
这星系本身是一个大圆盘 The galaxy itself is a huge disk
有巨大的螺旋形臂, 中间凸起 with giant spiral arms and a bulge in the middle.
这只是宇宙里众多星系的其中之一 It's just one of a huge number of galaxies in the universe.
首先, 星系是巨大的星群 Galaxies are first and foremost... large collections of stars.
一个星系平均有一千亿颗恒星 The average galaxy may contain a hundred billion stars.
那是恒星的孕育地 They are really stellar nurseries,
恒星诞生和灭亡的地方 the place where stars are born and where they also die.
星系里面的恒星诞生的时候 The stars in a galaxy are born
只是一团尘埃和气体, 叫星云 in clouds of dust and gas called nebulas.
这些是鹰星云的创生之柱 These are the pillars of creation in the Eagle Nebula,
位于银河系深处的恒星孕育地 a star nursery deep in the Milky Way.
我们的银河系有几十亿颗恒星 Our galaxy contains many billions of stars,
当中很多有行星和卫星环绕运转 and around many of them are systems of planets and moons.
不过我们一直对星系的认识不多 But for a long time we didn't know much about galaxies.
一百年前还以为宇宙只有银河系 Just a century ago, we thought that the Milky Way was all there was.
科学家称之为我们的宇宙岛 Scientists called it our island universe.
他们以为没有其它星系 For them, no other galaxies existed.
直至1924年 Then in 1924,
天文学家哈勃改变了这一切 astronomer Edwin Hubble changed all that.
哈勃在洛杉矶附近的威尔逊山上 Hubble was observing the universe
以当时最先进的… with the most advanced telescope at the time,
100寸胡克望远镜观察宇宙 the 100-inch Hooker on Mt. Wilson near Los Angeles.
他在深邃的夜空里 Deep in the night sky,
见到很遥远的地方有模糊的光点 he saw fuzzy blobs of light that were far, far away.
他知道那些不是独立的恒星 He realised they weren't individual stars at all;
而是一大群恒星 they were whole cities of stars.
那些是在银河系以外的星系 Galaxies way beyond the Milky Way.
天文学家对存在感受到巨大的震惊 Astronomers had an existential shock in one year,
一年内由以为宇宙只有银河系 we went from the universe being the Milky Way galaxy
到知道了宇宙有几十亿个星系 to a universe of billions of galaxies.
哈勃作出了在天文学历史里… Hubble had made one of the greatest
其中一个最伟大的发现 discoveries in the history of astronomy.
宇宙不只有一个星系 univers contains not just one
而是成千上万个 but great number of galaxies
适是漩涡星系 This is the Whirlpool galaxy.
它有两条巨大的螺旋臂 It has two giant spiral arms
里面有大约1亿6000万颗恒星 and contains around 160 million stars.
M-87星系 And galaxy M-87
是巨大的椭圆形星系 giant elliptical galaxy.
那是宇宙里历史最悠久的星系之一 It's one of the oldest in the universe
里面的恒星发出金黄色的光 and the stars glow gold.
这是草帽星系 And this is the Sombrero galaxy.
巨大的核心发光 It has a huge glowing core
被一圈气体和尘埃包围 with a ring of gas and dust all around it.
星系很壮观 Galaxies are gorgeous.
它们在某种意义上 They represent, in some sense,
代表宇宙的基本单位 the basic unit of the universe itself.
它们像巨型焰火轮, 在太空里转动 They're like gigantic pinwheels twirling in our space.
像大自然制造的烟火 It's like fireworks created by Mother Nature.
星系很巨大, 非常巨大 Galaxies are big. Really, really big.
在地球上, 我们以英里量度距离 On Earth, we measure distance in miles.
在太空里, 天文学家用光年做单位 In space, astronomers use light-years.
那就是光在一年内走的距离 The distance light travels in a year.
差不多等于六兆英里 That's just under six trillion miles.
我们离银河系中心2万5000光年 Here we are 25,000 light-years away from the centre of our galaxy,
银河系的阔度超过10万光年 and our galaxy is over a hundred thousand light-years across.
不过即使大如银河系 But even that, as large as it is,
以宇宙距离来说只不过是个小斑点 is kind of a speck in the cosmic distance scale.
银河系在我们眼里很巨大 Our Milky Way galaxy may seem big to us,
不过跟其它星系相比 but compared to some others out there,
其实很细小 it's actually pretty small.
跟我们最接近的银河邻居仙女座 Andromeda, our nearest galactic neighbour
阔度超过20万光年 is over 200,000 light-years across,
体积是银河系的两倍 twice the size of the Milky Way.
M-87是宇宙里最大的椭圆星系 M-87 is the largest elliptical galaxy in our own cosmic backyard
比仙女座大得多 and much bigger than Andromeda.
可是跟这巨物相比, M-87很细小 But M-87 is tiny compared to this giant
阔600万光年的IC 1011 Six million light-years across,
是已发现最大的星系 1C 1011 is the biggest galaxy ever found.
比我们的银河大60倍 It's 60 times larger than our Milky Way.
我们知道星系很大, 而且无处不在 We know galaxies are big and they're everywhere,
可是为甚么? but why is that?
天体物理学的其, 一个最大的疑问 One of the very big questions we have
就是星系从哪里来? in astrophysics is where galaxies come from.
我们不能完全理解 We really don't have a complete understanding of that
宇宙来自我们所说的大爆炸 The universe started in what we call a big bang.
那是在大约137亿年前 An extremely hot, extremely dense phase
这阶段酷热, 而且密度非常大 about 13.7 billion years ago.
我们知道那时候不可能有星系存在 We know that nothing like a galaxy could have existed at that time.
所以星系一定是诞生出来的 So galaxies must have been born.
它们一定是在最早期的宇宙形成的 They must have formed out of that very early universe.
要有引力才能形成恒星 It takes gravity to make stars
要更大的引力令恒星聚集成星系 and even more gravity to pull stars together into galaxies.
最早的恒星在大爆炸后二亿年形成 The first stars formed just 200 million years after the big bang.
引力把它们拉在一起形成早期星系 Then gravity pulled them together building the first galaxies.
哈勃太空望远镜让我们窥看过去 The Hubble Space Telescope has allowed us to peer back in time
回到差不多天地初开的时候 to almost the dawn of time.
那时候星系刚开始形成 The period when galaxies have just begun to form.
咍勃望远镜见到很多星系 The Hubble sees lots of galaxies,
不过我们今日见到那些星系的光 but the light we see today from those galaxies
是几千年, 几百万年… left there thousands, millions,
甚至几十亿年前遗留下来的 even billions of years ago.
经过那么久才传到来让我们看到 It's taken all that time to reach us.
今日见到的是那些星系的古老历史 So what we see today is the ancient history of those galaxies.
我们在咍勃深空里见到一些小污点 When we look at the Hubble Deep Field, what we see are little smudges.
一点不像今日见到的星系 They don't look much like the galaxies we see today.
那些只是仅能辨别的小光点 They're just little smudges of light that we can barely discern.
那些小光点里有数百万至数十亿颗 Those smudges of light contain millions or billions of stars
刚开始聚集在一起的恒星 that have just begun to merge together.
这些微弱的光点就是最早的星系 These faint smudges are the earliest galaxies of all.
它们大约在宇宙初开后十亿年形成 They were formed around one billion years after the beginning of the universe.
不过那只是哈勃能看到最远的情景 But that's as far back as Hubble can see.
若想回到更久远的从前 If we want to go even further back in time,
就需要另一种望远镜 we need a different kind of telescope,
这望远镜太大, 无法射上太空 one too big to launch into space.
我们在智利北部的沙漠上有一个 Well, now we have one in the high desert of northern Chile.
这是ACT, 阿卡塔玛宇宙望远镜 This is ACT, the Atacama Cosmology Telescope.
高1万7000尺 At 17,000 feet,
是全世界最高的地面望远镜 it's the highest ground-based telescope in the world.
我很喜欢在ACT的极端环境下工作 I really like working in the extreme environment of ACT.
经常非常寒冷, 风很猛烈 It's very, very cold often and the wind blows violently.
不过好处是从我们的角度来说 But the good thing about it from our point of view...
天空几乎所有时间都非常清晰 is that the sky is very, very clear, almost all the time.
ACT的精确镜子要对准最早的星系 Clear skies are important
就一定要有清晰的天空 for ACT's precise mirrors to focus on the earliest galaxies.
ACT让我们把某部分的天空放大 With ACT, we're able to zoom in
看到前所未见的细节 with unprecedented detail on parts of the sky.
我们还可以研究结构的形成过程 We can also study the progress of growth of structures,
像星系或星系团等结构 where structures or things like galaxies or clusters of galaxies
看到极细微的细节 with a very fine scale detail.
ACT不是侦测可见光 ACT doesn't detect visible light
它侦测宇宙微波 It detects cosmic microwaves
追溯到宇宙只有几十万年历史之时 from the time the universe was just a few hundred thousand years old.
这望远镜不只能侦测早期的星系 The telescope not only detects early galaxies,
还能看到它们怎样成长 it actually sees how they grew.
我们可以追踪 We're able to track the progress
星系和星系团形成的过程 of the formations of galaxies and clusters of galaxies.
看到由宇宙只有几十万年历史 We see the footprints of all the galaxies
直到今天这段期间 that have grown in the time
所有星系留下的足印 between when the universe was a few hundred thousand years old till now.
ACT帮助天文学家了解… ACT has helped astronomers understand how galaxies have evolved
由天地初开至今, 星系怎样演化 since almost the beginning of time itself.
你可以开始回答这些问题: You can start answering the question:
「星系年轻的时候是怎样的? 」 "What did galaxies look like when they were young?"
「跟今日的星系有何分别? 」 "How did they compare with modem day galaxies?"
「它们是怎样成长的? 」 "How have they grown?"
天文学家见到星系怎样由一群恒星 Astronomers are seeing how galaxies evolve from groups of stars
演化成今日见到拼凑而成的星系 into the patchwork of systems we see today.
我们现今的理解是恒星形成星群 Our current understanding is that stars form clusters
星群形成星系, 星系形成星系团 that build into galaxies, that build into clusters of galaxies,
星系团形成超星系团 that build into super clusters of galaxies,
那是今日见到在宇宙里最大的结构 the largest structures we observe in the universe today.
早期的星系很混乱 Early galaxies were a mess,
只是一团团的恒星、气体和尘埃 lumpy bunches of stars, gas and dust.
今日的星系看起来却整齐有序 But today galaxies look neat and orderly.
混乱的星系怎会变成… So how do messy galaxies transform
漂亮的螺旋形和焰火轮? into beautiful spirals and pinwheels?
答案是引力 The answer is gravity.
引力塑造星系, 并控制它们的未来 Gravity shapes galaxies and controls their future.
在大部分星系的中心 There is an unimaginably powerful and incredibly destructive source of gravity
都有极强大且破坏力惊人的引力 at the heart of most galaxies.
在我们的银河系深处也有一股引力 And there's one very deep at the centre of our own Milky Way.
星系存在了超过120亿年 Galaxies have existed for over 12 billion years.
我们知道这些巨大的恒星帝国 We know these vast empires of stars
有各种不同的形状和体积 come in all shapes and sizes,
由旋转的螺旋形, 到巨大的球状 from swirling spirals to huge balls of stars.
不过我们对星系仍所知不多 But there's still a lot about galaxies we don't know.
星系怎会有现在的形状? How did galaxies come to have the shapes they do?
螺旋星系是不是一直是螺旋形状? Was a spiral galaxy always a spiral galaxy?
答案几乎肯定是不 The answer is almost certainly no.
很年轻的口星系是一团混乱无序的… Very young galaxies are messy and chaotic,
恒星、气体和尘埃 a jumble of stars, gas and dust
经过几十亿年后 Then, over billions of years,
演化成秩序井然的结构 they evolve into neat, organised structures
像漩涡星系 like the Whirlpool galaxy.
或我们的银河系 Or our own Milky Way.
我们的银河系最初不是… Our Milky Way began
一个单一的小星系, 而是很多个 not as a single baby galaxy but many.
今日的银河系曾经包含… What is now our Milky Way was once
很多细小的结构 comprised of lots of small structures,
不规则形状的物体开始合并 irregularly shaped objects that began to merge.
引力把那些细小的结构拉在一起 The thing that pulls the small structures together is gravity.
逐渐地把恒星往内拉 Gradually, it pulls stars inward.
它们开始越转越快, 并变成圆盘 They begin spinning faster and faster and flatten into a disk.
恒星和气体被卷成巨大的螺旋臂 Stars and gas are swept into huge spiral arms.
这过程在宇宙里重复好几十亿次 This process was repeated billions and billions of times across the universe.
这些星系各有不同 Each of these galaxies looks different.
却有一个相同之处 But they do have one thing in common,
它们都环绕中心运行 they all seem to orbit something at their centre.
一直以来, 科学家都很想知道… For years, scientists wondered
甚么巨大力量足以改变星系的行为 what could be powerful enough to change how a galaxy behaves.
他们找到了答案 They found out.
黑洞 A black hole.
不是任何一种黑洞 And not just any kind of black hole.
而是超级巨大的黑洞 A super massive black hole.
超级黑洞存在的第一个迹象 The first clue that super massive black holes existed
是在一些星系的中心 was at the heart of some galaxies,
有一股巨大的力量从中心散发出来 there was an immense amount of energy emanating out from the centre.
我们见到这些黑洞… What we're seeing is the black holes
和这些星系在吞食周围的物质 and these galaxies feasting on the material around them.
像丰富的感恩节晚餐 So it's like having a huge Thanksgiving dinner.
那些食物就是气体和恒星 The meal is gas and stars.
被那超级巨大的黑洞吞食 and it's being eaten by the super massive black hole.
黑洞吃的时候有时会吃得太快 When black holes eat, they sometimes eat too fast...
把晚餐以纯能量束的形态吐出来 and spit their dinner back out into space in beams of pure energy.
那就是类星体 It's called a quasar.
科学见到类星体从星系爆发出来 When scientists see a quasar blasting from a galaxy,
就知道那星系有一个超级黑洞 they know it has a super massive black hole.
我们的银河系又怎样? But what about our galaxy?
这里没有类星体 There's no quasar here.
意思是没超级黑洞吗? Does that mean there's no super massive black hole?
安德烈姬斯跟她的队员 Andrea Ghez and her team have spent
这15年来一直在找答案 the last 15 years trying to find out.
在银河中心发现超级黑洞的关键 So the key to discovering a super massive black hole at the centre of our Milky Way
是观察恒星怎样移动 is to watch how the stars move.
恒星移动是因为引力 The stars move because of the gravity,
像行星环绕太阳运转 just like the planets orbiting the sun.
可是最接近银河中心的恒星 But the stars closest to the centre of the galaxy
被一团尘埃云遮盖 are hidden by clouds of dust
姬斯用在夏威夷的巨型凯克望远镜 So Ghez used the giant Keck telescope in Hawaii
看穿那团尘埃云 to look through the clouds.
她见到一个古怪且残酷的地方 What she saw was a strange and brutal place.
在银河系中心, 一切都变得更极端 Everything is more extreme at the centre of our galaxy.
对象移动得极快 Things move really fast
恒星高速刷过对方 and stars are gonna be whizzing by one another.
风很大, 很狂暴 It's windy. It's violent.
跟银河系里面的其它地方很不同 It's unlike any place else in our galaxy.
姬斯跟队员拍摄绕中心运转的恒星 Ghez and her team began to take pictures of a few stars orbiting near the centre.
目的是制作影片观察在中央的恒星 The task has been to make a movie of the stars at the centre.
要很有耐性, 因为拍了一幅照片 And--so you have to be patient because you take a picture
然后拍另一张, 才能见到它移动 and then you, you take another one and you see it move.
恒星的照片揭露令人讶异的事实 The pictures of the orbiting stars revealed something amazing.
它们在以时速几百万英里移动 They were moving at several million miles an hour.
我们拍第二幅照片的时候 When we had the second picture,
也是这实验最刺激的时刻 was the most exciting point in this experiment
因为我们清楚见到恒星高速移动 because it was clear to us that these stars were moving so fast
表示有超级黑洞的假设是正确的 that the super massive black hole hypothesis had to be right.
事实如此 And it was right.
姬斯跟队员追踪恒星的活动 Ghez and her team tracked the movement of the stars
指出它们在环绕甚么运转 and pinpointed what they were orbiting.
只有一件对象有足够的力量 There's only one thing powerful enough
把巨大的恒星这样抛出去 to sling big stars around like that
那就是超级黑洞 a super massive black hole.
超级黑洞的引力令恒星运转 It's the gravity of the super massive black hole that makes these stars orbit.
那弧度确实地证明了 So the curvature was the definitive proof of a super massive black hole
在银河系中心有超级黑洞 at the centre of our galaxy.
银河系中心的黑洞非常巨大 The black hole at the centre of the Milky Way is gigantic,
阔1500万英里 15 million miles across.
那么地球有危险吗? So is Earth in any danger?
我们绝对没有危险 We are in absolutely no danger of being sucked
不会被那超级黑洞吸进去 into our siper massive black hole.
因为太遥远了 It's simply too far away.
地球跟在银河系中心的超级黑洞 In fact, the Earth is 25,000 light-years away from the siper massive black hole
距离2万5000光年 at the centre of the Milky Way.
相等于好几兆英里 That's many trillions of miles.
地球暂时安全 The Earth is safe for now.
超级黑洞可能是巨大引力的来源 Super massive black hole maybe the source of huge amounts of gravity
却不足以把星系拉在一起 but they don't have enough power to hold galaxies together.
根据物理定律, 星系应该会飞开 In fact, according to the laws of physics, galaxies fly apart.
为甚么不会这样? So why don't they?
因为宇宙里有… Because there's something out there
力量比超级黑洞强大的东西 even more powerful than a super massive black hole.
它不能被看见, 也不能探测 It can't be seen and it's virtually impossible to detect
那是暗物质, 无处不在 Its called dark matter, and it's everywhere.
天文学家知道了超级黑洞 Astronomers have figured out that super massive black holes
存在于星系中央, 把恒星高速拉动 live at the heart of galaxies and pull stars at incredible speeds.
不过力量不足以束缚所有恒星 But they're not strong enough
形成一个巨大的星系 to hold all the stars in a gigantic galaxy together.
那么是甚么把它们拉在一起? So, what does hold them together?
那一直是个谜 It was a mystery
直至一位我行我素的科学家 until a maverick scientist came up with the idea
想到有我们不知道的东西在运作中 that something unknown was at work.
20世纪30年代 Back in the 1930's,
瑞士天文学家弗里茨兹威基 Swiss astronomer, Fritz Zwicky, wondered
想知道星系怎会聚集成群 why galaxies stayed together in groups.
他计算出星系产生的引力并不足够 By his calculations, they didn't generate enough gravity
所以它们应该飞开 so they should fly away from each other.
于是他说: And so he said,
我知道它们没有飞散 Well, I know that they haven't flown apart.
我见到它们聚集成这整齐的形状 I see them all gathered together in this nice collection.
所以一定有东西把它们拉在一起 Therefore something must be holding them in place.
不过我们的引力不够强 But our own gravity was just not strong enough.
所以他得出结论 And so he concluded that it must be something
那一定是没有人探测到或想过的… which nobody had detected before, nobody had thought about,
他称之为暗物质 and he gave it this name, dark matter.
那是天才的想法 And this was really a stroke of genius.
弗里茨兹威基的思想走快了几十年 Fritz Zwicky was decades ahead of his time.
所以他激怒了天文学界 And that's why he grated on the astronomical community.
不过他是对的 But, you know, he was right.
若是他说的暗物质令星系形成群体 If what Zwicky called dark matter held galaxies together in groups,
或也是暗物质把个别星系拉在一起 perhaps, it also holds individual galaxies together.
为找答案, 科学家用计算机仿真星系 To find out, scientists built virtual galaxies in computers
还模拟了恒星和引力 with virtual stars arid virtual gravity.
我们在模拟实验中令很多粒子运转 We did a simulation where we put a lot of particles in orbit..
形成一个扁平的圆盘 in a flat disk...
像我们的银河系那样 which was just like the picture of our galaxy.
我们预料会见到一个有秩序的星系 And we expected to find that we get a perfectly good galaxy.
期待看它是不是螺旋形状 We were looking to see if it has a spiral or whatnot
结果却发现它每次都散开 But we found that it always came apart.
银河系的引力不足以把它拉在一起 There just wasn't enough gravity in the galaxy to hold it together.
奥斯迪卡于是加入模拟暗物质引力 So Ostriker then added extra gravity from virtual dark matter.
那是很自然的尝试, 结果问题解决 It seemed like a natural thing to try and it solved the problem.
那就是答案 It fixed it.
暗物质的引力把星系拉在一起 Gravity from dark matter held the galaxy together.
暗物质作为星系的保护骨架 Dark matter acts as a sort of protective scaffolding for galaxies
令牠们维持稳定的结构 that really holds them up and holds them in place
不会散开 and prevents them from falling apart.
科学家如今发现了暗物质… Now scientists are discovering that
不只是把星系拉在一起 dark matter doesn't just hold galaxies together,
还可能为星系带来生命 it might have sparked them into life.
我们相信暗物质在大爆炸下形成 We think that dark matter was created out of the big bang.
暗物质开始凝集成团 And dark matter began to clump.
这团暗物质最后变成核心 And these dumpings of dark matter eventually became the nuclei,
那是我们银河系的种子 the seeds for our galaxy.
不过科学家仍不知道暗物质是甚么 But scientists still have no idea what dark matter actually is.
暗物质很古怪, 我们对它毫无认识 Dark matter is weird because we don't understand it at all.
那显然不是构成我或你的物质 It's clearly not made of the same stuff that you or I are made of.
你不能推它, 不能感觉到它 You can't push against it. You can't feel it.
可是它却在我们的周围 Yet, it's probably all around us.
这像鬼魅般的物质能穿过你 It's a ghost-like material that will pass right through you
就像你不存在那样 as if you didn't exist at all.
我们对暗物质一无所知 We might not know much about dark matter,
暗物质却充斥宇宙 but the universe is full of it.
以重量的比例计算 So the dark matter, weight for weight,
跟构成我们的普通物质相比 makes up at least six times as much of the universe
暗物质占宇宙成分至少多六倍 as does normal matter, the stuff that we're all made from.
若没有它 And without it,
宇宙根本不能运作 the universe just wouldn't work the way that it seems to work.
宇宙在运作, 所以暗物质或是真的 But the universe does work, so maybe dark matter is real.
很奇怪的东西 Strange stuff.
最近在深太空探测到暗物质 And recently, it's been detected in deep space,
非直接地, 而是观察它对光的影响 not directly, but by observing what it does to light
它令光弯曲, 这过程叫引力透镜 It bends it in a process called gravitational lensing.
引力透镜让我们探测暗物质的存在 Gravitational lensing really allows us to detect the presence of dark matter.
当来自遥远星系的光束 And the way they works is that as a beam of light from some distant galaxy
向我们传过来的时候 is travelling towards us,
若经过一大团暗物质 if it passes by a large collection of dark matter,
在暗物质的引力影响下 its path will be deflected around that dark matter
光的路径会出现偏斜 by the gravitational pull.
用哈勃望远镜遥望宇宙深处的时候 When the Hubble telescope looks deep into the universe,
一些星系的确像变形和被拉长了 some galaxies do seem distorted and stretched.
那是因为暗物质令影像弯曲 That's caused by the dark matter which warps the image.
就像看着一个金鱼缸那样 It's sort of like looking through a goldfish bowl.
探索那些星系的形状和扭曲程度 By probing the shapes of those galaxies and the degree of distortion,
就能准确地量度那里的暗物质份量 we car really measure very accurately the amount of dark matter that's there.
现在知道暗物质是宇宙的主要成分 It's clear now that dark matter is a vital ingredient of the universe.
由天地初开就在运作 It's been working since the dawn of time
影响一切, 无处不在 and affects everything, everywhere.
它触发星系诞生, 令它们不会散开 It triggers the birth of galaxies and keeps them from falling apart.
我们无法看见或探测它 We can't see it or detect it
暗物质却是宇宙的主宰 But nevertheless, dark matter is the master of the universe.
星系看似孤立 Galaxies look isolated.
事实如此, 它们相隔几万兆英里 It's true, they are trillions of miles apart
不过它们是一个群体, 叫星系团 But actually they live in groups called clusters.
几万个星系团聚合在一起 And these clusters of galaxies are linked together in super clusters
连结成超星系团 containing tens of thousands of galaxies.
我们的银河系在哪里? So where does our Milky Way galaxy fit in?
若你看这幅大图画就会知道 If you take a look at the big picture,
银河系是本地星系群的一部分 you realise that our galaxy is part of a local group of galaxies,
为数大约30个 perhaps 30.
银河系和仙女座是这本地群之中 And our galaxy and Andromeda
最大的两个星系 are the two biggest galaxies in this local group.
不过若你望向更遥远的地方 But if you look even farther out,
就见到我们属于室女座超星系团 we are part of the Virgo super cluster of galaxies.
科学家在绘制宇宙的完整结构图 Scientists are now mapping the overall structure of the universe
标示星系团和超级星系团的位置 and the position of clusters and super clusters of galaxies.
这是位于新墨西哥的阿帕奇天文台 This is Apache Point Observatory in New Mexico,
在这里进行斯隆数字巡天探测SDSS home to the Sloan Digital Sky Survey or SDSS.
这小望远镜价值不菲, 有特别任务 It's a small telescope with a big price tag and it has a unique mission.
SDSS在绘制第一幅夜空立体地图 SDSS is building the first 3-D map of the night sky.
这过程要辨认数千万个星系的位置 A process that's identifying the exact positions of tens of millions of galaxies.
SDSS在太空里搜寻星系 To do it, SDSS goes galaxy-hunting way out into space,
远远超越了我们的银河系 far beyond our Milky Way.
它指出星系的位置 It pinpoints the positions of galaxies
这数据被复制到铝盘上 and this information is copied onto aluminium disks.
这些铝盘阔大约30寸 These aluminium disks are about 30 inches across
每块上面640个洞 and they have 640 holes each.
这些洞代表天空里的目标物体 And these holes correspond to the objects of interest in the sky.
每一个物体就是一个星系 Each object is a galaxy.
星系的光会被引导 Light from the galaxy is channelled
经过一个洞, 沿光纤电缆向下传送 through a hole and down a fibre optic cable.
这方法记录数千个星系的… This method records data
距离和位置数据 on distance and position from thousands of galaxies
然后标示它们的立体位置 and plots their location in 3-D.
我们由此得知它们的形状 It's telling us about their shape.
得知它们的结构 It's telling us about their makeup.
得知它们的分布 It's telling us how they're distributed.
这些在天文学上和对宇宙的了解 And all of this is very important to astronomy
者非常重要 and understanding our universe.
他们在绘制最大的立体地图 And this is what they're creating, the biggest 3-D map ever.
这地图让我们看到从没看过的东西 The map is showing us things we've never seen before.
它标示出星系团和超星系团 It shows galaxies in clusters, in super clusters.
再扩大范围就会见到这些超星系团 But pull back even more, and we see that these super clusters
互相连结成丝状结构 are connected into structures called filaments.
SDSS找到一个阔140亿光年的结构 SDSS has found one that's 1.4 billion light-years across.
它叫做斯隆宇宙巨墙 It's called the Great Sloan Wall
是在科学史上发现的最大单一结构 and it's the largest single structure ever discovered in the history of science.
你感觉到置身一个很辽阔的地方 You get a sense that, that you are in something quite vast.
星系团和丝状结构的数据呈现眼前 You could see the clusters and filaments as the data would scroll by.
每一个模糊的小斑点 And. and, you know, each one of these little fuzzy spots
其实是星系, 不是恒星, 是星系 were, were actually galaxies, not stars, but galaxies.
你见到的是整个星系团 And so you're seeing whole clusters of these things.
SDSS显示出大规模的银河地理 SDSS is showing galactic geography on a vast scale.
科学家更进一步 Scientists have taken it even further.
在超级计算机里制造了整个宇宙 They've built the whole universe in a super computer.
在这里见不到个别的星系或星系团 Here, you can't see individual galaxies, you can't even see galaxy clusters.
你见到的是超星系团 What you can see are super clusters
在广大的宇宙网络里连成丝状结构 linked together on filaments in a vast cosmic web.
当你开始从浩大的宇宙往后退 As one begins to come back from the whole scale of the universe.
就会见到这些丝状结构 one begins to reveal a filamentary pattern,
这宇宙网络包含星系和星系团 a cosmic web of containing galaxies and clusters of galaxies
这些星系燃亮宇宙 that light up the universe where there's many galaxies
遍布在不同的方向 in that direction as that direction, as that direction and that direction.
以较大的规模看, 宇宙有点像海绵 And, in fact, on larger scales, the universe kind of looks like a sponge.
每个丝状结构里有数百万个星系团 Each of the filaments is home to millions of galaxy clusters,
全部被暗物质束缚在一起 all bound together by dark matter.
在这计算机仿真里 In this computer simulation,
暗物质沿着丝状结构发光 the dark matter glows along the filaments.
暗物质决定星系在宇宙哪位置形成 Dark matter affects where in the universe galaxies will form.
当我们观察星系 When we look at galaxies,
就见到它们不是随意地散布的 they're not sprinkled around at random.
它们趋向形成细小的群体 They actually tend to form in little groups.
这其实反映了暗物质的大规模分布 And that's really reflecting the large-scale distribution of dark matter.
暗物质是黏合宇宙超级结构的胶水 Dark matter is the glue holding together the whole superstructure of the universe.
把星系、星系团和超星系团黏起来 It binds galaxies and clusters and clusters In super clusters.
它们互相被锁紧在丝状结构里 All these are locked together in a web of filaments.
若没有暗物质 Without dark matter,
宇宙的整个结构就会散开 the whole structure of the universe would simply fall apart
这是我们的宇宙大观 This is the big picture of our universe.
这是一个巨大的宇宙网络 It's a giant cosmic web.
银河系隐藏在一个丝状结构的深处 And hidden deep in one of these filaments is the Milky Way.
银河系已存在了差不多120亿年 It's been around for nearly 12 billion years.
不过在未来 But in the future,
它会在一场巨大的宇宙碰撞中灭亡 it's going to be destroyed in a gigantic cosmic collision.
星系是庞大的恒星王国 Galaxies are vast kingdoms of stars.
有些是巨球, 有些是复杂的螺旋形 Some are giant balls and others complex spirals.
最重要是它们永远在变 The thing is, they never stop changing.
我们观察银河系的时候 While it may seem when we look out at our galaxy
以为它是静止的 that our galaxy is static
以为它一直存在, 其实不是的 and been here forever, it's not.
我们的银河系是一个动态的地方 Our galaxy's a dynamic place.
它的特性在宇宙的时间里一直在变 Its very nature has been changing over cosmic time.
星系不只会变, 还会移动 Galaxies not only change, they move as well.
有时会互相碰撞 And sometimes, they run into each other.
在碰撞下会吞食对方或被吞食 And when they do, it's eat or be eaten.
宇宙是一个星系动物园 There's a zoo of galaxies that you can find out there.
这个动物园会跟动物园的其它成员 And this entire zoo can interact or collide
互捐影响或碰撞 with any of the other members of the 200.
这是NGC-2207 This is NGC-2207.
看起来像一个巨型双螺旋星系 It looks like an enormous double spiral galaxy.
不过这其实是两个星系在碰撞中 But it's actually two galaxies colliding.
碰撞持续几百万年 The collision will last millions of years.
到了最后, 两个星系会变成一个 And eventually, the two galaxies will become one.
这种碰撞在宇宙里无处不在 Collisions like this happen all over the universe.
我们的银河系也不例外 Our own Milky Way is no exception.
事实上, 银河系是吞食同类的动物 The Milky Way is, in fact, a cannibal
目前存在的形态… And it exists in its present form
就是在吞食其它小星系下形成的 by having cannibalised small galaxies that it literally ate up.
今日我们仍能见到细小的星河 And today, we can see small streams of stars
那是在吞食下形成银河系的时候 that are left over from the most recent mergers
遗留下来的痕迹 that have formed the Milky Way galaxy.
不过跟即将发生的事相比却差得远 But that's nothing compared to what's coming up.
我们将会跟仙女座星系碰撞 We are on a collision course with the galaxy Andromeda.
对银河系来说, 这是坏消息 And for the Milky Way, that's bad news.
银河系正在以时速大约25万英里 Our Milky Way galaxy is approaching Andromeda...
撞向仙女座 at the rate of about a quarter of a million miles per hour.
那就是说在50至60亿年后 Which means that in five to six billion years,
银河系会消失 it's all over for the Milky Way galaxy.
整个仙女座正在向我们高速飞过来 You would see the entire Andromeda galaxy speeding towards us,
直撞向我们 really barrelling straight into us.
两个星系互相影响下 As the two galaxies interact
两者都越来越受扰乱且越来越接近 they both become more and more disturbed and closer and closer together.
这过程开始迅速加快 And the whole process starts to snowball.
两个星系会展开一场死亡舞蹈 The two galaxies will enter a death dance.
这是加速了几百万倍下的模拟碰撞 This is a simulation of the future collision sped up millions of times.
两个星系碰撞 As the galaxies crash together,
气体和尘埃云从四方八面喷射出来 clouds of gas and dust are thrown out in all directions.
两个星系结合下的引力 Gravity from the merging galaxies
把恒星扯离轨道 rips stars from their orbits
抛进深太空里 and shoots them deep into space.
随着银河系的末日逼近 As we approach doomsday for the Milky Way galaxy,
场面会很壮观 it would be spectacular.
我们坐在最前排目击银河系的灭亡 We would have a front row seat on the destruction of our own galaxy.
最后, 两个星系会穿过对方 Eventually, the two galaxies will go right through each other
然后退后, 合为一体 and then come back and then coalesce.
奇怪的是恒星不会碰撞 It's strange but the stars themselves won't collide.
因为它们相隔很远 They're still too far apart.
所有恒星都会互相擦过对方 All the stars are basically just gonna pass right by each other.
一颗恒星撞向另一颗恒星的可能性 The probability of one individual star hitting another individual star
基本上是零 are basically zero.
不过恒星之间的气体和尘埃被加热 However, the gas and dust between the stars will start to heat up.
最后会燃烧 Eventually, it ignites
两个碰撞的星系日发炽热的光芒 and the clashing galaxies will glow white---hot
所以在某个时候, 天空或会着火 So at a certain point, the sky could be on fire.
我们认识的银河系和仙女座会消失 The Milky Way and Andromeda, as we know it, will cease to exist
一个面貌全新的银河仙女系诞生 And Milkomeda will be born and it will look like a whole new galaxy.
这新的银河仙女星系 This new galaxy, Milkomeda,
会是一个巨大的椭圆星系 will become a huge elliptical galaxy
没手臂或螺旋形状 without any arms or spiral shape.
要发生的事无法避免 There's no escaping what's going to happen.
问题是地球会怎样? The question is, what's it mean for planet Earth?
我们可能会被抛进外层空间里 We may either be thrown out into outer space.
当银河系的螺旋臂被扯开 When the arms of the Milky Way galaxy are ripped apart...
我们或会落入这新星系的肚里 or we could wind up in the stomach of this new galaxy.
恒星和行星会被推至四散 Stars and planets will be pushed all over the place.
所以地球很可能会灭亡 So this may well be the end of planet Earth.
宇宙里面的星系会继续互相碰撞 Galaxies all over the universe will continue to collide.
不过这银河吞食的时代将会过去 But this age of galactic cannibalism will eventually pass.
因为宇宙中有一股更强大的破坏力 Because there is an even more destructive force in the universe.
这股破坏力无法阻止 A force that nothing can stop.
它会把星系推开 It will ultimately push galaxies away from each other,
拉扯一切 stretching everything...
直至宇宙被撕破 untii the universe rips itself apart.
星系是恒星、太阳系… Galaxies are home to stars, solar systems,
行星和卫星的家园 planets and moons.
一切重要的事都在星系里面发生 Everything that's important happens in galaxies.
星系是宇宙的命脉 Galaxies are the lifeblood of the universe.
有人类出现全因为我们住在星系里 We arose because we live in a galaxy.
在宇宙里, 我们能见到的一切 And everything we can see
我们所重视的一切 and everything that matters to us in the universe
都在星系里发生 happens within galaxies.
不过星系只是由暗物质束缚的… But the truth is galaxies are delicate structures
脆弱结构 held together by dark matter.
科学家发现了宇宙有另一股力量 Now scientists have found another force at work in the universe.
这股力量叫暗能量 It's called dark energy.
暗能量跟暗物质的作用相反 Dark energy has the opposite effect of dark matter.
暗能量不是把星系拉在一起 Instead of binding galaxies together,
而是把星系推开 it pushes them apart.
我们在过去十年才发现的暗能量 The dark energy which we've only discovered in the last decade,
是在宇宙里的支配物质, 神秘得多 which is the dominant stuff in the universe, is far more mysterious.
我们对它为何存在一无所知 We don't have the slightest idea why it's there.
我们不知道它的成分 What it's made from, we don't really know.
只知道它存在 We know it's there,
却不知它是甚么或在做甚么 but we don't really know what it is or what it's doing.
暗能量很古怪 Dark energy is really weird
就像太空里有一些小弹弓 It's as if space has little springs in it...
令对象互相排斥, 推开对方 which are causing things to repel each other and push them apart.
科学家相信在遥远的未来 Far in the future,
暗能量会在宇宙战争里赢了暗物质 scientists think that dark energy will win the cosmic battle with dark matter.
那场胜利会开始令星系散开 And that victory will start to drive galaxies apart
暗能量会令星系灭亡 Dark energy's gonna kill galaxies off.
它的做法是令所有星系… It's gonna do that
离我们越来越远 by causing all the galaxies to recede further and further away from us
直至见不到 until they're invisible,
以比光速快的速度远离我们 until they're moving away from us faster than the speed of light.
所以宇宙会在我们的眼前消失 So the rest of the universe will literally disappear before our very eyes,
不是今天或明天, 而是几兆年之后 not today, not tomorrow, but in perhaps a trillion years,
宇旨将会消失 the rest of the universe will have disappeared.
星系会变成深太空里的孤独前哨 Galaxies will become lonely outposts in deep space.
不过那将会是非常遥远的事 But that's not going to happen for a very, very long time.
宇宙如今仍在茁壮成长 For now. the universe is thriving.,.
星系在创造让生命存在的适合条件 and galaxies are creating the right conditions for life to exist
没有星系就没有我, 没有你 Without galaxies, I wouldn't be here. You wouldn't be here.
也许根本不会有生命 Perhaps life itself wouldn't be here.
我们很幸运, 地球上能有生命 We're lucky, life has only evolved on Earth
全因为我们那细小的太阳系 because our tiny solar system
在银河系适合的位置诞生 was born in the right part of the galaxy.
若更接近中心, 那就不会有我们了 If we were any closer to the centre, well, we wouldn't be here.
在星系中心的生存条件极端恶劣 At the centre of a galaxy, life can be extremely violent.
若我们的太阳系更接近银河系中心 And, in fact, if our solar system were closer to the centre of our galaxy,
辐射会很强, 令我们无法存在 it would be so radioactive that we couldn't exist at all.
离中心太远同样糟糕 Too far away from the centre would be just as bad.
在外围的恒星没那么多 Out there, there aren't as many stars.
我们或无法存在 We might not exist at all.
所以在某种意义上 So in some sense,
我们在银河系的适居区内 we are in the Goldilock zone of the galaxy.
不太近, 不太远, 刚刚好 Not too close, not too far, but just right.
科学家相信在这星系适居区内 Scientists believe that this galactic Goldilocks zone
可能有数百万颗恒星 might contain millions of stars.
所以也许有其它太阳系 So there may be other solar systems
像我们的银河系那样能孕育生命 that can support life right here in our own galaxy.
若我们的银河系有适居区 And if our galaxy has a habitable zone,
其它的星系也可能有 then other galaxies could too.
宇宙无边无际 The universe is, is immense.
最奇妙是我们的发现也是无限的 And though, the amazing thing is that we1re always discovering more.
每次当我们以为找到了一个答案 Every time we think we know the answer to one problem.
却发现里面隐藏着一个更大的问题 we find it's embedded in a much bigger problem.
那很精彩刺激 And that's exciting.
在我们的银河系和其它宇宙星系里 There are endless questions to ask and mysteries to solve.
有无穷无尽的问题和谜团要解答 In our own galaxy, the Milky Way, and in galaxies all across the universe.
十年前谁会想得到… Ten years ago. who would have thought
我们能确定中心的黑洞? that we'd be able to identify the black hole at the centre?
十年前谁想得到 Who would have thought 10 years ago
天文学界会相信暗物质和暗能量? that the astronomical community would believe in dark matter and dark energy?
越来越多科学研究以星系为焦点 More and more, scientific research is focusing on galaxies.
星系包含着宇宙运作的关键 They hold the key to how the universe works.
我们该庆幸能活在这时候 We should be amazed to live at this time,
在宇宙历史里的某一刻 here at a random time in the history of the universe.
在某个星系外缘的某个行星上 on a random planet at the outskirts of a random galaxy.
让我们能发问和理解… where we can ask questions and understand things
由宇宙初开到灭亡的一切 from the beginning of the universe to the end.
我们该享受在太阳下的短暂时刻 We should celebrate our brief moment in the sun.
星系诞生 Galaxies are born.
演化 They evolve.
碰撞 They collide.
最后灭亡 And they die.
星系是科学界的超级巨星 Galaxies are the superstars of the scientific world.
连研究它们的科学家都各有所爱 And even the scientists who study them have their favourites.
漩涡星系或M-51 The Whirlpool galaxy or M-51.
若要我选一个, 我喜欢草帽星系 I kind of like the Sombrero galaxy, if I had to put one on a wall.
草帽星系和环星系, 它们赏心悦目 The Sombrero galaxy, Ring galaxies, they're just beautiful to look at.
我最喜欢的星系是银河系 My favourite galaxy is the Milky Way galaxy.
那是我真正的家园 It's my true home.
我们很幸运 We're lucky that the Milky Way
银河系提供适合我们生存的条件 provides the right conditons for us to live.
我们的命运跟银河系… Our destiny is linked to our galaxy
和所有星系相连 and to all galaxies.
它们制造我们 They made us.
塑造我们 They shape us
我们的未来在它们的手里 and our future is in their hands.
翻译/摘订时间轴/校对：啥时候摇中