这是一颗正在爆炸的恒星 This is an exploding star.
叫超新星 It's called a supernova.
超新星是宇宙的最大灾难 A supernova is the greatest cataclysm in the history of the entire universe.
超新星大小不一, 形态各异 Supernovas come in different sizes and types.
全部极其明亮, 宇宙各处都能看见 All of them are so bright they can be seen across the universe.
超新星是恒星死亡时的剧烈爆炸 A supernova is the most violent death of a star you can imagine.
但正是恒星的这种猛烈的毁灭 But this violent destruction of a star...
催生了宇宙万物 is also the birth of everything we see around us.
宇宙有道理 How the Universe Works
第1季第5集：超新星 Supernovas
巨型恒星死亡时的爆炸叫超新星 Really big stars go out with a bang called a supernova.
超新星的亮度可以超过整个星系 A supernova can outshine... an entire galaxy,
释放的能量是太阳的数万亿倍 releasing trillions of times the energy of our sun.
超新星只需在距离地球几十光年远 They're so violent, if one of them exploded just a few dozen light-years away,
已足以烤焦地球 planet Earth would be toast.
一颗距离近的超新星会毁灭地球 A nearby supernova would really ruin our day.
首先大量辐射会烧焦大气层 First of all, the sudden burst of radiation would scorch the atmosphere.
唯一能躲避的地方就是地下 The only place to go is underground.
只有在地下 Underground, you could then withstand
才可以抵御X光的炙烤 the blistering burst of X-rays which hit the Earth...
然后X光会令所有植物枯萎 and then it would scorch all plant life.
一旦食物链崩溃 And with the collapse of the food chain,
地球上的生物会完全灭绝 we're talking about a possible extinction on the Earth.
超新星是杀手 Supernovas are killers.
但也创造构成我们世界的基本元素 But they also create the basic elements that make up our world.
地球, 太阳, 我们周围的万物 Our planet, our star... everything around us formed
都来自于一个恒星爆炸后的残骸 out of the debris of a dead exploded star.
构成人类身体和那些大厦的物质 Everything that makes up our bodies and the skyline
都是来自超新星 came from supernovae.
所有的铁, 所有硅 All of the iron, all of the silicon,
构成这些建筑物的所有元素 all of the elements that went into these buildings.
构成血液和身体的物质 The things that make up my blood, my body,
结婚戒指中的金子 the gold in my wedding ring,
这里所有一切都来自超新星 everything you see here is a supernova.
但太阳不会变成超新星, 它太小了 But our sun won't become a supernova. it's too small.
恒星本质上是一个巨大的核反应堆 Like all stars, it's basically a giant nuclear reactor.
恒星内的核聚变反应堆燃烧氢 The fusion reactor inside a star burns hyc^ogen,
氢是最简单和最普遍的元素 the simplest, most common element
反应将氢原子聚合在一起 The reaction fuses hydrogen atoms together...
产生氦气和能量 producing helium and energy.
当氢消耗殆尽时 And when the hydrogen runs out,
恒星继续燃烧, 将氦气聚变成碳 stars keep burning by fusing helium into carbon...
再将碳聚变成氧 then carbon into oxygen.
当像太阳这类小恒星开始产生碳时 When small stars like our sun make carbon,
它们就开始死亡 they begin to die.
在恒星的生命中, 向内拉的引力 During the lifetime of a star
和向外推的压力保持平衡 there's a balance between gravity pulling in and pressure pushing out.
对于仍在产生能量的恒星 For a star... that's generating energy,
完全没有问题 there's no problem.
但一旦停止产生能量 But once energy generation switches off,
压力就会消失, 引力会大获全胜 the pressure goes away and gravity wins.
现在引力开始挤压恒星的内核 Now gravity begins to crush the centre of the star.
恒星外层被向外推 The star's outer layers are pushed outwards.
膨胀成一个巨大气体球叫红巨星 They expand into a huge ball of gas called a red giant.
当太阳在45亿至50亿年后死亡时 Our sun, when it dies four and a half to five billion years from now...
日冕将延伸到火星 its corona will go all the way out to Mars.
地球上的一切都将蒸发 Everything on the planet Earth will vaporise.
太阳外层膨胀的同时 While the outer layers expand,
内核的引力将产生相反的力 in the centre of the sun, gravity will have the opposite effect
把太阳内核压至原体积百万分之一 It will crush the sun's core to just a millionth of its original size,
形成跟地球等大的球体 about the size of the Earth.
这个由氧和碳组成的致密球体 Now it's a dense ball of oxygen and carbon
叫白矮星 called a white dwarf.
对太阳系来说, 这就是末日 In our solar system, this will be the end of the story.
恒星毁灭时产生的气体将逐渐消散 The gas from the dying star will gradually disperse...
但白矮星会持续燃烧数十亿年 but the tiny white dwarf will burn for billions of years.
但太阳系很特别, 它仅有一颗恒星 But our solar system is unusual, it has just one star.
其实大多数恒星都是成对出现的 The fact is the vast majority of stars orbit in pairs.
若两颗恒星中的一颗变成白矮星 When one of the two stars dies and becomes a white dwarf,
在距离足够近的情况下 if it's close enough,
它会从另一颗恒星上偷取物质 it starts stealing material from the other star.
想想看, 两颗恒星互相围绕旋转 Think of two stars rotating around each other.
一颗恒星从伴星慢慢地吸走所有氢和氦 One star slowly sucking all the hydrogen and helium from its companion star.
像吸血鬼一样 It's like a vampire.
当白矮星从伴星吸取越来越多燃料 As the white dwarf sucks more and more fuel out of its companion star,
将变得更重 密度更大和更不稳定 it gets heavier and denser and less stable.
在内部, 碳原子和氧原子即将聚合 Inside, carbon and oxygen atoms are about to fuse together.
这是坏消息 And that's bad news.
白矮星其实像一颗随时引爆的炸弹 A white dwarf, in some sense, is like a bomb waiting to be lit
白矮星蕴藏着巨大能量 There's a huge amount of energy - stored in that star,
包括引力能和核能 gravitational energy and nuclear energy.
这颗白矮星正在变成一只怪物 This white dwarf is turning into a monster,
一颗1A型超新星 a Type 1A monster.
1A型超新星 A Type 1A supernova...
是个200亿亿亿百万吨热核碳炸弹 is a 20 billion, billion, billion megaton thermonuclear carbon bomb.
它是宇宙中最易爆炸的物质之一 It's one of the most explosive substances in the universe.
最终白矮星从伴星吸取了足够物质 Eventually, the white dwarf drains so much material from its companion,
进入核超载状态 it goes into nuclear overload.
内部的碳和氧开始转变成… The carbon and oxygen inside it start to turn
一种极普通却又极危险的元素 into a common but dangerous element, at least to stars.
你可能在星空奇遇记中看过 You've probably seen in Star Trek
有某种神秘科技能够杀死恒星 the idea that there is some sort of secret technology that kills a star.
其实它就在你用来做早餐的煎锅里 Well, I mean it, it's in your frying pan that you used this morning for breakfast,
那就是铁 iron.
白矮星开始将碳和氧聚变成铁 The moment the white dwarf star starts to fuse carbon and oxygen into iron,
它便注定要毁灭 it's doomed.
突然, 白矮星爆炸了 Suddenly, the white dwarf explodes.
白矮星的核爆产生了很多东西 The nuclear explosion of a white dwarf include, among other things,
包括大量的铁 huge amounts of iron.
其实1A型超新星有重大作用 And in fact, Type 1A supernovae are of vital importance
它们令宇宙布满… to populating the universe with the kind of elements
对我们至关重要的元素 that are important to us.
1A型超新星将铁喷射到数万亿哩外 Type 1A supernovas blast iron trillions of miles into space.
宇宙中大部分铁来自超新星 It's where most of the iron in the cosmos comes from.
但比铁重的元素, 如金和银呢? But what about all the elements that are heavier than iron, like gold and silver?
它们又来自哪里呢? Where do they come from?
答案是其它恒星 The answer again is other stars.
单星 更大的恒星 Single stars. Bigger stars.
超新星创造了宇宙万物 Supernovas make everything in the universe.
地球上所有物质 Everything we see, all the material in planet Earth,
都是在超新星内部创造的 was created inside a supernova.
连你和我也同样源自垂死的恒星 Even you and I are made from dying stars.
没有超新星, 我们不会存在 Without supernovae, we wouldn't be here.
身体中每个原子都来自爆炸的恒星 Every atom in your body was once inside a star that exploded.
也许我们左手的原子与右手的原子 And the atoms in your left hand
来自两个不同的恒星 may have come from a different star than the atoms in your right hand.
你其实是星尘 You are literally stardust.
太阳系中几乎所有的铁来自… Almost all of the iron in our solar system came from a double star supernova
一个50多亿年前爆炸的双子超新星 that exploded more than five billion years ago.
从地球的内核到摩天大楼 From our planet's molten core - to our skyscrapers...
再到血液中的血红蛋白 to the haemoglobin in our blood.
都是由来自1A型超新星的铁构成的 it's all made of iron from Type 1A supernovas.
但较重的元素, 像金, 银和铀 But the heavier elements in our world, like gold, silver and uranium,
则来自另一种超新星 come from another type of supernova...
单星超新星 a single star supernova.
这是太阳 This is our sun.
重量远大于太阳的单星 A single star has to weigh much more than oir sun
才可能成为超新星 to go supernova.
这些巨星确实存在 And there are sane monster stars out there.
有些比太阳重数十倍 Some are dozens of times heavier than our sun.
有些重数百倍 And some are hundreds of times more massive.
越重的恒星, 燃烧得越快 The heavier the star, the faster it burns.
一旦这些庞然大物开始衰老和死亡 And when these massive stars begin to age and die,
内部的核反应便会加速 the nuclear reactions inside them speed up.
巨星消耗核燃料非常迅速 Giant stars bun through their nuclear fuel very, very fast
这有点像放纵生活, 英年早逝 It's sort of the, you know, the live fast, die young.
恒星的质量越大 The more mass a star has,
内部燃烧的温度越高 the hotter it burns inside,
燃料消耗得也就越快 the faster it burns through its fuel.
与双子超新星不同的是 Unlike double star supernovas,
巨型单星在爆炸前创造了大量元素 really massive single stars create lots of elements before they explode.
一旦将氢转化成氦 Once they turn hydrogen into helium,
氦转化成碳, 和碳转化成氧 helium into carbon, and carbon into oxygen,
它们不会塌缩成白矮星 they don't collapse into white dwarf stars.
相反这颗巨星会继续燃烧 Instead, giant stars keep on burning...
在内核深处形成一层层新元素 building up layer after layer of new elements deep in their core.
巨星将氦转成碳和氧后不会停下来 Big stars don't stop after they've burned helium to carbon and oxygen.
它们继续燃烧, 将碳烧成更重元素 They go ahead and burn carbon to still heavier elements
然后将氖和氧转化成硅 and then neon and oxygen to silicon...
直到形成一个像俄罗斯套娃一样的 until you get this nested Russian doll...
球形千层糕 spherical layer cake kind of thing.
这些元素是构成宇宙的基础材料 These elements are the bui I ding blocks of the universe...
但它们被困在巨星内部 but they're trapped inside the giant star.
它们总会出来的 Somehow they've got to get out.
通过研究爆炸的恒星 Studying exploding stars has taught us
我们发现重元素是如何形成的 how the heavy elements of the universe came to be.
它们形成于巨星内部的核反应 They were formed... by nuclear reactions inside stars.
但若有些巨星没有爆炸 But if some of those stars were not to explode,
那么这些元素将永远封存 then those elements would be locked up forever.
引发巨大单星释放元素的原因 The trigger that will release the elements in the single giant star
正是同样引发1A型超新星爆炸的 is the same element that causes the Type 1A supernova to blow up...
铁元素 iron.
铁耗尽恒星核聚变产生的所有能量 Iron eats up all the energy of the star's nuclear fusion.
没有了核聚变能量向外扩张的压力 Without the energy from nuclear fusion pushing out,
引力开始向内挤压 gravity begins to crush down.
巨星注定要毁灭 The big star is doomed.
恒星的最后时刻非常壮观 The last moments of a star are really phenomenal.
恒星也许经历了1000万年 The star might last for 10 million years
才成为超新星 on the way to becoming a supernova,
但最后一刻来得非常迅速 but the last little bit takes place very rapidly.
一旦具备铁质内核和一旦失去平衡 Once you have an iron core and once it gets out of balance,
它就会在一毫秒内塌缩 it col lapses in a thousandth of a second, a millisecond,
就如同从地球变成曼哈顿那么小 from the size of the Earth down to the size of Manhattan.
塌缩时以三分之一光速的速度移动 It's travelling about one-third of the speed of light as it crunches down.
当恒星变得不稳定时 As the star becomes unstable,
巨大引力引起内核塌缩 the massive power of gravity causes the core to collapse.
这过程释放出巨大能量 This happens with such incredible power,
致使内部原子也开始挤压在一起 even the atoms inside start to crush together.
当恒星逐渐变小和密度变大 As it gets smaller and denser,
内核开始累积越来越多能量 the core builds up more and more energy.
它的质量是太阳的1.5倍 It's something with about one and a half times the mass of the sun
而塌缩后的直径只有15英里 that has collapsed to something that's only about 15 miles across.
密度的确大得惊人 It's got incredible density.
是水的密度的一千万亿倍 You know, it's a thousand trillion times the density of water.
现在这颗恒星爆炸了 Now, the star explodes.
爆炸穿透恒星外层 The blast rips through the star's outer layers,
在过程中创造出所有比铁重的元素 and in the process, makes all the elements heavier than iron.
铁变成钴 Iron becomes cobalt
钴变成镍 Cobalt becomes nickel.
然后变成金, 铂和铀 And on and on to gold, platinum and uranium.
爆炸很短暂 The explosion is so brief
只制造了少量重元素 it only makes small amounts of these heavier elements,
这也是它们这样稀少的原因 which is why they're so rare.
超新星把这些新元素 The supernova blasts these new elements
喷射到数十亿哩外的太空中 billions of miles into space.
我们知道的唯一方法 The only method we know,
宇宙里能够创造新元素的… the only mechanism that we have found anywhere in the universe
唯一途径 for creating new elements...
就是在作垂死挣扎的恒星 is in the death throes of a star.,.
叫做超新星 called a supernova.
令人难以置信的是会有物质… It seems incredible that anything
能在超新星的爆炸中幸存下来 could survive a supernova explosion...
但我们现在知道 but we now know
宇宙一些大爆炸留下了遗骸 that some of the biggest bangs in the universe leave a corpse behind.
它们非常奇特, 兼且极度危险 And these are some of the strangest and most deadly objects ever discovered.
超新星爆炸后不一定意味着终结 When a giant star goes supernova and explodes, it's not always the end.
有时会留下遗骸 Sometimes there's a corpse.
遗骸的种类取决于恒星的大小 What kind of corpse depends on the size of the star.
比太阳大八倍的恒星形成的超新星 Supernovas from stars more than eight times bigger than our sun
会留下一颗中子星 leave behind a neutron star.
这是宇宙中最奇特的物体之一 And it's one of the strangest objects in the universe.
它们好像星体世界的僵尸 These things you can almost think of... as sort of the zombies of the stellar world.
它们非常危险, 非常诡异 They're very dangerous. They're very weird.
恒星不断制造它们, 四周围都是 And stars make them all the time. They're all around us.
当一颗巨星变成超新星时 As a giant star goes supernova,
内核从行星被挤压到城市般大小 the core is crushed from the size of a planet to the size of a city.
内核承受的压力十分强烈 The pressure in the core is so intense...
连内部原子也挤压在一起 even the atoms inside it are crushed together.
当原子被紧紧挤压, 以致全无空隙 When the atoms are packed that tightly and there's no space left between them,
内核累积的巨大能量需要得到宣泄 the massive energy build-up means something's got to give.
内核爆炸摧毁了恒星外层 The core blasts off the outer layers of the star...
留下密度超大的中子星 and what remains is a super-dense neutron star.
中子星是把恒星的质量压缩到极小 A neutron star has the mass of a star crunched into a very small volume...
所以密度大得惊人 and that means the density is incredibly high.
想象我身后的帝国大厦 Well, imagine taking the Empire State Building here behind me,
压缩成一粒沙子那么大 crushing it into the size of a grain of sand.
这就是中子星的密度 That's the density of the entire neutron star.
若这种极高密度的东西掉下去 So if you had something that dense, if you dropped it,
它会像热刀切牛油那样穿过地球 it would fall straight through the Earth just like a hot knife through butter.
一茶匙大小的中子星有一亿吨重 A teaspoon of neutron star would weigh 100 million tons.
想象恒星那样重的东西 Imagine something as heavy as a star,
却只有纽约市那么大 but only the size of New York City...
而且在旋转 and it's spinning.
有些的转速达到每秒1000转 Some of them...may be born rotating a thousand times a second.
试想一下 I mean, think about it.
质量是太阳1.5倍的天体 Something one and a half times the mass of the sun
每秒旋转1000次 going around a thousand times a second.
有些中子星旋转得很快 Some neutron stars spin so fast,
因而产生巨大的辐射脉冲 they generate huge pulses of energy...
从星体的两极喷射出来 beams of radiation blasting out of the star's north and south poles.
这样的中子星叫做脉冲星 This neutron star is called a pulsar.
蟹状星云中心就有一颗脉冲星 There's one of these things in the centre of the Crab Nebula.
一千年前一颗超新星在哪里爆炸 The place where there was a supernova explosion about a thousand years ago...
它是转速最快的脉冲星之一 and it's one of the fastest-spinning of these objects.
这是射电望远镜记录的 This is the actual sound a pulsar makes
脉冲星发出的声音 recorded by radio telescope.
它会以每秒30次的频率 It will flash 30 times a second
持续闪烁数百万年 for millions of years.
但脉冲星并不是超新星所能留下的 But pulsars aren't the strangest thing
最奇特东西 a supernova can leave behind.
当比太阳大30倍的恒星爆炸时 When stars 30 times bigger than our sun explode,
会产生一种中子星, 叫磁星 they produce a type of neutron star called a magnetar.
磁星比脉冲星更为奇异 Magnetars are even weirder than pulsars
它能产生强大磁场 and generate powerful magnetic fields.
最极端, 磁场能达到10至15… Now, in the most extreme case, the magnetic field can be 10 to the 15,
是地球磁场的100万亿倍 you know, a hundred trillion times the magnetic field of the Earth.
磁力之大, 能在数千哩外… That's so strong, it would suck the iron right out of your blood
将我们血液中的铁吸走 from thousands of miles away.
但脉冲星和磁星都不是… But even pulsars and magnetars aren't the most dangerous objects
超新星所能留下最危险的东西 a supernova can leave behind.
当特大质量星的内核塌缩时 When the core of a super-massive star collapses,
不仅压缩原子, 还会压缩时空 it doesn't just crush atoms, it crushes space and time itself.
这时超新星就会创造出 And that is when a supernova creates
黑洞 a black hole.
当比太阳重100倍的恒星爆炸时 When stars over 100 times heavier than our sun explode...
形成的超新星爆炸非常巨大 they make a supernova explosion so big...
科学家们称之为超超新星 scientists call them hypernovas.
超超新星几乎引发第三次世界大战 And it was a hypernova that almost started World War III.
1963年美苏同意禁止核武器试验 In 1963, the US and Soviet Union agreed to ban testing nuclear weapons.
为了密切监视俄国人的动向 To keep tabs on the Russians,
美国发射了间谍卫星 the US launched spy satellites.
当听到来自太空深处的这种声音 When they heard this sound coming from deep space,
他们怀疑发生最坏的情况 they suspected the worst.
美国政府发射了维拉号卫星 The United States government launched... the Vela satellite
来探测核爆炸 looking for nuclear detonations.
他们在外层空间看到了这些巨大爆炸 And then, looking in outer space, they saw these monster explosions take place.
军方想: 天哪, 俄国人 And the military thought, "Oh, my God, the Russians,
俄国人在太空试验秘密核武器 the Russians are testing secret atomic weapons in space."
但这些不是秘密原子弹试验 But these weren't secret atomic bomb tests
也跟俄国人毫无关系 and the Russians had nothing to do with them.
他们开始寻找辐射的来源 They begin to look at where this radiation came from.
它来自整个银河系和银河系之外 It came from all over the galaxy, beyond the galaxy.
俄国人不可能将爆炸物 Now, there's no way the Russians could shoot explosions in outer space
发射到银河系以外的外层空间 beyond the galaxy.
于是人们开始意识到这是全新事物 And then people began to realise that we were staring something new in the face.
这些超强爆炸释放出的高能量辐射 They were super-powerful explosions of high energy radiation
叫伽马射线暴 called gamma-ray bursts.
问题是它们来自哪里? The question was where did they come from?
答案是爆炸的超超新星 The answer was exploding hypernovas.
在普通的超新星爆炸中 During a regular supernova explosion,
引力将星体内核压缩成中子星 gravity crushes a star's core into a neutron star.
但在超超新星爆炸, 星体大得多 But during a hypernova explosion, the giant star is so much bigger
令引力将内核压缩成更奇异的东西 that gravity crushes the core into something much stranger.
黑洞 A black hole.
黑洞立即开始吞噬恒星的其它部分 And the black hole immediately begins to devour the dying star around it.
剩下部分不能被细小黑洞全部吸收 The rest of the star can't all go in that little bitty hole in the middle.
它开始旋转, 形成吸积盘 It starts to swirl around... and it forms an accretion disc...
每秒向黑洞提供 which is feeding the black hole
相当于地球质量100万倍的食物 at about a million Earth masses a second.
将会发生戏剧性变化是理所当然的 And so as you might imagine, something dramatic is gonna happen here.
每秒100万个地球令黑洞难以消化 A million Earth masses a second is too much for the black hole to consume all at once.
所以它以接近光速将很多物质吐出 So it spits a lot of it back out at nearly the speed of light
形成两股能量束从黑洞喷射出来 This creates two beams of pure energy blasting their way out of the black hole.
穿透恒星只需八秒 It takes it about eight seconds to bore through the star,
非常集中, 从表面喷发出来 keeping a very tight focus, and erupt from the surface.
若站在喷射口, 会看到伽玛射线暴 Now, if we're standing in the opening of this jet, we'll see a gamma-ray burst.
产生于黑洞的伽玛射线 The gamma rays produced from the black hole
冲破恒星外层飞入太空 tear through the outer layers of the star and into space.
伽玛射线暴是我们所知的 Gamma-ray bursts are the most violent event...
宇宙中最猛烈的活动 that we know of in the universe.
巨星爆炸后形成黑洞 A giant star blows itself to pieces and forms a black hole.
场面极其壮观 It's incredibly spectacular.
这些伽玛射线暴能量巨大 These gamma-ray bursts are so energetic,
它们可以照亮整个宇宙 they light up the entire universe.
宇宙中的任何地方 Any point in the universe
最终都会接收到 will eventually pick up this astounding radiation
来自伽玛射线暴的辐射 coming from a gamma-ray burst
可见它们的能量有多高 That's how energetic they are.
它们是已知宇宙中最亮物体 They are the brightest things in the known universe.
一个典型超新星爆炸产生的能量 To put things in perspective, a typical supernova explosion
比超新星还要亮1亿倍 is a hundred million times more luminous than a supernova.
它们无疑是宇宙中最亮的东西 They're the champions for brightness, for sure.
它们不仅亮, 而且破坏力极大 They're not only bright, they're letha
若伽玛射线暴击中地球 If a gamma-ray burst were to hit the Earth,
会在数秒内毁掉大部分大气层 it would destroy most of the atmosphere in seconds.
伽玛射线暴就像步枪射击 A gamma-ray burster is like a riffle shot.
若你在瞄准在线 And if you're in the line of sight
当心 watch out.
一旦被辐射击中 Once the radiation hits you,
地球表面将会被一氧化氮笼罩 it will bathe the entire surface of the Earth with nitric oxides
臭氧层将荡然无存 which will wipe out the ozone layer.
炙热辐射将摧毁植物和藻类 Blistering radiation would hit plant life, hit algae,
整个食物链将会崩溃 the whole food chain would collapse.
若射线暴够接近 If the burst was close enough,
会引起大规模生物灭绝 it would cause mass extinctions.
伽玛射线暴… Gamma-ray bursts turn out to be a lot more common
远比我们想象的常见 than we thought they would be.
很可能有些曾袭击过地球 So it's possible that some of these have even hit the Earth in the past.
那是很可怕, 可能已发生过 That's a pretty scary scenario, it may already have happened.
问题是若它发生过, 会再发生吗? The question is if it happened before, could it happen again?
伽玛射线暴像打了类固醇的超新星 A gamma-ray burster is basically a supernova on steroids.
一颗巨星爆炸死亡 a giant star to die violently.
离我们最近而有可能发生这种事的 Now, the nearest star to us that might do that
就是海山二 is Eta Carinae.
这是壮丽的星云 And it's a spectacular nebula.
各种物质正在从这颗恒星中喷出 There's all kinds of material flying off this star.
它极不稳定 It's very unstable.
很可能已放射过伽玛射线暴 It may already have exploded in a gamma-ray burst.
但海山二可能并不是唯一的威胁 But Eta Carinae may not be the only threat.
还有其它垂死的恒星 There are other dying stars out there.
其中一个正指向地球方向 Believe it or not, one of them is pointed in our direction.
我们正盯着WR 104的炮筒 We are staring down the gun barrel of WR 104,
这双星总有一天会爆发伽玛射线暴 two dying stars that will one day undergo a gamma-ray burst.
问题不是会不会, 而是几时 Not a question of if. A question of when.
WR 104的袭击名单中也许有地球 That WR 104 may have our name on i t.
但好消息是 But the good news is...
我们可能不会预先知道 we probably wouldn't know about it in advance.
我们还没来得及反应就已被击中了 The shock would hit us before we had a chance to do anything.
所以担心是没用的 So there's no sense worrying about it, anyway.
事实上我们永远不会知道一颗恒星 The truth is we'll never know if a star
是否即将变成超新星和爆炸 is about to go hypernova and explode.
等看到它爆炸时, 已为时晚矣 Anyway, by the time we see it, it will already be too late.
其实我们时刻暴露在 In fact, we're already exposed to rays
濒死恒星放出的辐射中 from dying stars every second of every day.
当巨星爆炸 When giant stars explode...
那是宇宙中最猛烈的爆炸 they make the biggest bangs in the universe.
是甚么赋予它们如此巨大威力? But what gives them so much punch?
直至最近才揭开这谜团 Until recently, no one knew.
当科学家想在计算机仿真超新星爆炸 Scientists, when they tried to simulate a supernova explosion in a computer,
他们遇到了难题 had a problem.
他们无法从垂死恒星获取足够能量 They simply could not get enough energy...
形成超新星 out of the dying star to create a supernova.
这是天文学的灾难 This was a calamity in astronomy.
计算机模型无法仿真恒星爆炸 Computer models couldn't make the simulated stars blow up.
要使恒星爆炸, 需要巨大能量 To blow up a star, you need a lot of energy.
问题是天文学家无法找到这种能量 The trouble was astronomers coulckn't find it
可见的辐射是释放的总能量中 The visible radiation that you see is a tiny
极其微小部分 fraction of the total energy emitted.
即使气体膨胀产生的动能 Even the energy of motion... of the expanding gases
也仅占总能量的 is only one percent of the total energy.
其余的99%能量在哪里呢? Where was the missing 99 percent of the energy from the explosion?
要使模拟脗合真实情况的唯一方法 The only way scientists could get their simulations to match the real thing
就是加入一种神秘粒子, 叫中微子 was to add in a mysterious particle called the neutrino.
没中微子, 数字加起来与总数不符 Without it, their numbers didn't add up.
这是容易的部分 That was the easy bit
下一步是证明超新星产生中微子 Their next step was to prove supernovas really do produce neutrinos.
1987年, 他们获得好运 In 1987, they got lucky.
16.8万年前一颗超新星 168,000 years ago, a supernova exploded in a nearby galaxy
在接近的大麦哲伦星云爆炸 called the Large Magellanic Cloud.
当科学家们看到来自爆炸的光线时 When scientists saw the light from the blast,
他们将它命名为超新星1987 they called it Supernova 1987.
超新星1987A对于超新星研究 Supernova 1987A is really important...
十分重要 in the study of supernovae
因为这是自望远镜发明以来 because its the first one
我们发现的第一颗超新星 since the invention of the telescope.
我们利用现有的一切工具 It's the one that we've been able to study right from the time of explosion through now
研究它从爆炸至今的全过程 using all the instruments that we've developed.
其中一种工具就是深埋地下的 One of those instruments was a giant neutrino detector
巨型中微子探测器 buried deep underground.
我们看到有辐射穿过中微子探测器 And bingo, we saw a burst of radiation go through our neutrino detectors
我们说: and we said "Ah-ha,
这就是证据 That's the proof."
发现来自超新星1987A的中微子 The discovery of neutrinos from Supernova 1987A
是意义重大的事 因为 was a tremendous thing because
多年来人们一直说 for many years, people had been saying,
其余99%的爆炸能量存在于中微子 "That's where 99 percent of the energy goes.
但没有人看到过它 But no one had ever seen it."
现在证据确凿, 我们能够证明 This is now the smoking gun that we can now prove
中微子携带了超新星的能量 that neutrinos carry the energy of a supernova.
我们在外层空间观测到超新星的同时 And we detected it right on the Earth
在地球上探测到了中微子 as we saw a supernova in outer space.
中微子比原子小几万亿倍 Neutrinos are trillions of times smaller than atoms.
从核电站到核弹再到恒星爆炸 They're created by all sorts of nuclear reactions...
所有类型的核反应都能产生中微子 from nuclear power plants and bombs to exploding stars.
若你能看见中微子, 它们无处不在 If you had neutrino vision, you'd see them everywhere.
中微子是像幽灵一样的粒子 Neutrinos are ghost-like particles.
就在我们讲话时 Literally trillions of them are going through my body
数万亿中微子穿过我们身体 even as we speak.
其实中微子来自于地下 In fact, neutrinos come from the bottom of the floor right through the Earth
也许正穿透我的双腿 and even hit me right through my legs.
真奇异 Pretty strange.
如此多微粒快速通过我们身体 Imagine so many tiny particles zooming through our bodies.
但它们的能量从哪里来呢? But where do they get all their energy?
当超新星的内核在爆炸前压缩时 When a core crushes down just before a supernova explosion,
里面的原子发生分裂 the atoms inside it are broken up.
内核热力将原子碎片聚变成中微子 The core gets so hot, it turns this atomic debris into blazing neutrinos.
当恒星内核塌缩成中子星时 We think that supernovae produce a stupendous sum of neutrinos
超新星产生了大量中微子 when the core collapses to a neutron star.
有约10秒时间 For about 10 seconds,
内核以中微子光度发光 that core... shines with a neutrino luminosity...
这比那一刻宇宙其它地方产生的… that is greater... than all of the energy being produced
所有能量都要大 in the rest of the universe at that time.
换言之, 它极其光亮 In other words, it's really bright.
但引力无法将这些中微子留在内核 But gravity can't hold these neutrinos in the core.
它们喷发出来和迸发耀眼光芒 They burst free in a blinding flash of light
将垂死恒星撕得粉碎 that rips the dying star apart.
中微子的发现改变了超新星的知识 The discovery of neutrinos transformed the science of supernovas.
但超新星即将揭示最神秘的力量 But supernovas were about to reveal the most mysterious force of all,
一种正在改变宇宙命运的力量 one that's changing the destiny of the universe.
超新星爆炸如此耀眼 Supernova explosions are so bright,
整个宇宙都能看到 we can see them across the entire universe.
天文学家利用它揭开了 This has helped astronomers unlock
宇宙中最神秘的谜团之一 one of the deepest mysteries of the cosmos.
宇宙在140亿年前大爆炸中诞生 The universe came to life in the big bang 14 billion years ago.
由一个比原子还小的极微小能量点 It expanded from a tiny ball of energy smaller than an atom
膨胀形成横跨亿万光年的宇宙 to a universe billions and billions of light-years across.
而且它仍在不断膨胀 And it's still expanding.
我经常想未来的人 I've often wondered how far future people
会对宇宙大爆炸知道多少 will even know the big bang happened...
因为我们知道大爆炸发生 because we know the big bang happened
是来自看到所有星系飞离我们 from watching all the galaxies fly away from us.
总有一天星系的距离会远到 Someday, the galaxies will be so far away from each other...
天空变成甚么也看不见 it will be impossible to see anything else in the sky.
科学家以前认为 Scientists used to think
宇宙膨胀速度正在减慢 the expanding universe was slowing down,
但没有办法证明这点 but there was no way to prove it
直到发现了la型双子超新星 until they found double star supernovas, Type 1A's.
当白矮星的质量 They always explode
达到太阳的1.4倍时就会爆炸 when the white dwarf star reaches exactly 1.4 times the mass of our sun.
爆炸通常会释放出等量的光 And their explosions always release exactly the same amount of light.
它们是测量太空距离的完美标记 They are the perfect markers to measire distance in space.
la型超新星 Type 1A supernovae,
若我们知道它们的实际亮度 when we know how bright they are
和它们的观测亮度 and how bright they look,
就能测出它们的距离 we can tell the distance...
因为距离越远 because the farther away they are,
在望远镜中看上去就越暗 the less bright they'll look in a telescope.
这能帮助我们准确地测量距离 And that has allowed us to accurately measure distances...
不仅能测出附近星系的距离 not just to nearby galaxies,
还可以测量到宇宙另一端 but to galaxies at the other end of the visible universe.
数十亿光年之外的星系的距离 billions of light-years.
这给我们带来了许多骜人发现 And that has allowed us to make incredible discoveries.
天文学家以为找到了方法去证明 Astronomers thought they had found a way to prove
宇宙膨胀速度正在减慢 the expansion rate of the universe was slowing down.
但事实却出人意料 What they got was a big surprise.
1998年天文学家有个惊人发现 In 1998, astronomers made a remarkable and unexpected discovery.
原本认为在引力作用下 It was recognised that the universe, which should be slowing down
宇宙膨胀速度正在减慢 because gravity, after all, is attractive,
而且物体的质量 and the mass of objects
应该令宇宙膨胀速度减慢 should cause the expansion of the universe to slow down...
但膨胀实际上在加速 but the expansion is speeding up, it's accelerating.
来自la型超新星的持续光线 The constant light from Type la supernovas
完全改变了天文学家对宇宙的理解 completely changed the way astronomers understand the universe.
每一本科学教科书都指出 Every science textbook on the Earth says
宇宙在膨胀和膨胀在减慢 that the universe is expanding and slowing down.
大错特错 Wrong.
我们现在必须改写 We now have to rewrite
所有科学教科书 all the science textbooks on the planet Earth.
但天文学家仍然不明白 But astronomers still didn't know why
为何宇宙会膨胀得越来越快 the universe is expanding faster and faster.
他们开始认为有一种未知的能量 They began to think it's some kind of unknown energy.
他们称之为暗能量 They called it dark energy.
但很难证明它的存在 But it's difficult to prove
因为它见不到, 摸不到, 探测不到 because it can't be seen or touched or detected.
我们对暗能量的物理性质和起源 We really don't have a very good clue
知道得非常少 as to the physical nature and origin of dark energy.
或许目前所有物理问题中 It's perhaps the number one...
最值得观测研究的 observational ly-motivated problem in all of physics right now,
就是暗能量的性质 the nature of the dark energy.
从暗能量到黑洞, 超新星解答了 From dark energy to black holes, supernovas have revealed
宇宙中一些最深奥的谜题 some of the most profound mysteries of the universe.
爆炸的恒星创造出宇宙的基础元素 These exploding stars give us the building blocks of the universe
和揭示宇宙形成的奥秘 and show us how it's all made.
这是很难想象 It's hard to imagine,
但今天构成我们身体的原子 but the atoms in our bodies today were made
源自数十亿年前爆炸的超新星 by a supernova billions of years ago.
圣经说: 生于尘, 归于尘 The Bible says, "From dust to dust."
天文学家说: 生于星尘, 归于星尘 Astronomers say, "From stardust to stardust"
超新星是生命循环中的关键环节 So supernovae are the key link in this cycle of life.
人们总认为太空 People think of space
十分遥远 as being something very distant and very remote,
距离我们以光年计, 遥不可及 it's light-years away, hugely distant from us.
这是完全错误的 That's completely wrong.
超新星就在这里 Supernovae are right here.
我们是它们的孩子 We are their children.
它们创造我们和将我们连在一起 They made us, literally put us together.
我们是星体一部分 We are star stuff.
没有超新星, 也就没有我们 Without the supernovas, we could not exist.
当我们在晚上漫步时 So when we walk around at night
抬头仰望夜空的星宿 and we look up at the night sky and we see the stars
我们觉得是它们一部分 and we feel somehow a part of them...
事实的确如此 the truth is we are.
是它们创造我们 They are our parents.
有些科学家相信超新星时代 Some scientists believe the age of supernovas
可能正在结束 could be ending.
像太阳一样, 体积小燃烧慢的恒星 Smaller, slower-burning stars, like our sun,
会变得更常见 will become more common,
而巨星会变得越来越少 and giant stars become more rare.
超新星创造了星系 Supernovas have given us galaxies,
太阳系, 恒星和行星 solar systems, stars, and planets.
它们创造了人类和宇宙万物 They made us and everything we see.
它们是毁灭和创造相接的地方 They are where destruction and creation meet.
宇宙的命运在于垂死恒星的灰烬 The destiny of the universe lies in tine ashes of dying stars.
翻译/摘订时间轴/校对：啥时候摇中