起初，一片黑暗，然后--轰--一声巨响-- In the beginning, there was darkness, and then-- Bang--
诞生了无限扩展的时间，空间，和物质的世界。 Giving birth to an endless expanding existence of time, space, and matter.
每天，都有新的秘密被解开 Every day, new discoveries are unlocking the mysterious,
在这个令人疯狂的极端之地，我们叫做“宇宙”的地方。 the mind-blowing, the deadly secrets of a place we call the universe.
我们的太阳有一个邪恶的伙伴么？ Could our Sun have an evil companion?
一颗未被探索的死星，在极远处旋转着 An undiscovered death star rotating at the furthest
是在我们太阳系边缘么？ edges of the Solar System?
是否这颗神秘的星体会定期 Does this mysterious star scatter destruction through
毁灭我们的太阳系？引发 the Solar System at regular intervals, accounting for the
我们地球历史上最大规模的毁灭？ greatest extinctions in Earth's history?
通过筛选广阔的宇宙和神秘的小行星 Sifting through a realm populated by giant worlds
科学家们正在搜寻一个神秘的天体， and mysterious planetoids, scientists are on the hunt
复仇女神...太阳的邪恶伙伴 for Nemesis... The Sun's evil twin.
复仇女神--太阳的邪恶伙伴
天空中，闪耀着数十亿颗星星， Of the billions of stars twinkling overhead,
也许有一个会威胁到地球的生命... one may be a scourge to life on Earth...
一个叫复仇女神的太阳的伴星。 An evil twin to the Sun named Nemesis.
有些科学家怀疑，这个复仇女神是一个暗淡的 Some scientists suspect that Nemesis is a dark,
未被发现的恒星，正围绕着我们的太阳。 still-undiscovered star orbiting our Sun.
每隔2千6百万年，就会引发一场灾难。 And every 26 million years, it triggers a disaster.
我们知道，太阳系被巨大的彗星云围绕着 We know that the Solar System is surrounded by this enormous
这些彗星云，会不断的把其中的彗星 cloud of comets, and so these successive passages of the Sun's
送进内太阳系里。 companion would send comets into the inner Solar System.
有些会袭击地球。 Some of them will hit Earth.
那会引起大规模的毁灭。 What follows is death on a colossal scale.
现在人们普遍认为 It is now widely accepted that a
曾经有一块来自外太空的巨石，结束了恐龙时代。 rock from space caused the end of the age of dinosaurs
那发生在6500万年前。 65 million years ago.
我们十分肯定，就是这个原因， So we now are pretty convinced that the reason that a
6500万年前地球上生命被毁灭的主要因素， huge fraction of life on the Earth went extinct 65 million
就是一颗彗星撞进了地球。 years ago was because a comet slammed into the Earth.
但是天文学家Richard Muller却提出了一个 But astronomer Richard Muller has proposed a
革命性的理论来解释，为什么太空岩石 revolutionary theory to explain why that space rock crashed to
在那个特定的时期撞击地球。 Earth at that particular moment.
这种复仇女神的理论，假设有一颗恒星， The Nemesis theory postulates that there's a star orbiting the
在离太阳2600万年的轨道上绕行。 Sun at a 26-million-year period.
差不多， That's about it.
几乎不用在做其他的假设了。 Almost no other assumptions need to be made.
Muller相信，当这颗复仇女神接近太阳， Muller believes that as Nemesis nears the Sun, its
引力扰动，会使彗星飞进太阳系里。 gravitational disturbance sends comets flying through the Solar System.
由此产生的影响，就是导致 The resulting impacts have been the source of many major
地球历史上许多主要灭绝事件的源头。 extinction events in Earth's history.
Muller解释了这个理论的由来。 Muller explains how the theory came about.
2位古生物学家，在寻找古生物灭绝的方式时， Two paleontologists, when looking at patterns of
遇到了一种疯狂的现象。 extinctions, came across something that seemed utterly insane.
他们说，类似的灭绝 They said that similar extinctions were taking place
每隔2600万年就会定期发生一次。 every 26 million years on a regular schedule.
他们发现，这种每隔2600万年的灭绝模式 The discovery of a 26-million-year pattern of
似乎是不可能靠地球自身的发展进程 extinctions seemed impossible to explain by any process native to
来解释这种情况。 the Earth itself.
这是一类幻想的自然科学的问题。 This is the sort of thing you dream about in science.
意味着有些事情我们不理解。 It means there's something we don't understand.
意味着有些事情等待发现。 It means there's a discovery waiting.
所以我开始试着找到一些端倪。 So I set about trying to figure out what that was.
Muller做出了一个惊人的报告。 Muller made an astonishing proposal.
这种周期性的灭绝时间，唯一合乎逻辑的原因就是 The only logical cause of these periodic extinctions is a cosmic
这个每隔2600万年出现在太阳轨道的宇宙暗影杀手 stalker that orbits our Sun every 26 million years,
彗星正令人不安的接近我们。 disturbing the comets on each approach.
总之，我们的太阳有一个死星伴侣。 In short, a death star companion to our Sun.
如果这颗恒星被发现，那将十分重要 If this star is discovered, it is so important.
它是地球生命演化的主要角色。 It was a major player in the evolution of life on Earth.
没有这个，也许恐龙仍在这里。 Without this, perhaps the dinosaurs would still be here.
如果Muller是正确的，人类自己也要感激 If Muller is right, humanity itself could owe its existence
复仇女神这颗死星。 to the Nemesis death star.
毕竟，每一次大规模的灭绝都消灭了大批 After all, each mass extinction wiped out vast numbers of
物种，每次也都为新物种的出现扫清道路， species, but each also cleared the way for new species to
也包括，人类的出现。 arise, including, ultimately, humans.
我们能够目睹这样的复仇女神 We can witness the way Nemesis
寻找一种可控的，改变地球进化的地方， would have altered evolution on Earth by looking at a controlled
加利福尼亚圣罗萨高原火灾。 burn on the Santa rosa plateau in California.
每一次，一些灾难性事件的发生， So every now and again, some cataclysmic event happens
都会消灭大量的物种 that wipes out a huge number of species here on Earth.
就像现在的这些 And this is just like happens
能被控制住的火灾，大火会消灭一定数量的物种 with these controlled burns, where the burn wipes out a
也会给新物种 number of species, which then makes room for new things to
腾出空间。 take hold.
所以我看我们后面的火灾肆虐。 So I'm seeing a fire raging behind us.
那儿发生了什么事? What's going on there?
为什么要点着它们？ Why do you light fires?
我们到这里这里放火是为了清除掉部分植被， We're out here setting this fire to clear part of this
清除那些长在这里的外来植物。 vegetation away, to get rid of the non-native species of plants
原生植被就能恢复了。 that are growing here so the native can grow back.
我们每年都在不同地点放火， We come here and burn annually in different plots of land so
这样可以研究 that it can be studied, and we can also see the impact it's
这种方式对环境的影响。 having on that environment.
这种指定的放火，类似 A prescribed fire mimics the kinds of
复仇女神引发的大规模灭绝的方式。 mass extinctions that Nemesis may have caused.
许多物种灭绝了，这些灭绝的物种腾出空间 Many species are swept away, but the destruction leaves room
使得幸存者得以蓬勃发展和演变... for the survivors to flourish and evolve...
就像哺乳动物的生存和茁壮成长，发生在恐龙 Just as mammals survived and thrived after the fiery death of
大规模灭绝之后，为人类的演化，提供了舞台。 the dinosaurs, setting the stage for human evolution.
这种指定地点的放火方式，每年都会返回圣罗萨， These prescribed fires return to Santa rosa every year and
这种就像复仇女神假说引发的灭绝 imitate the driving motivation behind the creation of the
一样--发生了一次又一次 Nemesis hypothesis-- That extinctions occur over and over.
真的只有两种可能的解释， There are really only two viable explanations for the
来说明这种规律性的灭绝。 regularity of the extinctions.
一个就是复仇女神理论 One of them is the Nemesis theory.
另一个就是像掷骰子一样的 The other is that by the throw of the dice they just
可能每隔2600万年偶然发生一次。 accidentally happen to line up every 26 million years.
但是怎么可能如此准确，复仇女神引发的灭绝 But how, exactly, would Nemesis trigger extinctions with
会像我们指定放火那样有规律？ the regularity of a prescribed burn?
答案可能就在位于太阳系外围的 The possible answer lies in a region of the Solar System known
奥尔特云。 as the Oort Cloud.
奥尔特云是彗星的冷库 The Oort Cloud is the place where comets are kept
彗星藏身其中，直到某一天 in cold storage until they come
它会呼啸着朝太阳冲去 screaming in towards the Sun.
这些深度冷冻的物体，就是这类物体 So these things are sitting in deep freeze, sort of at the
把我们跟最近的恒星间隔开来。 distance halfway between us and the nearest stars.
绝大部分的奥尔特云彗星 The vast majority of Oort Cloud comets
的轨道，都在距太阳一光年远的安全距离上。 orbit at the safe distance of up to one light year from the Sun.
也就是说，除非有什么搅乱了它们的轨道。 That is, unless something disturbs their orbits.
偶尔，某颗恒星的到来， Occasionally, a star will come by, and they get a little
会对这些彗星产生一点影响。 bit jostled.
这种小的挤撞，会引发很多事情。 And a little jostling can do a lot of things.
可以使它们离开，完全离开太阳系。 It can make them go away and leave the Sun entirely.
也可以轻轻的把它们推进不同轨道。 It can put them on a slightly different orbit.
但有一种情况，就是它可以把这些彗星推入某个轨道， But one of the things it can do is put them on an orbit that
再让它们慢慢地冲向太阳。 slowly falls in toward the Sun.
通过这名杂耍表演者， By following the motions of a juggler,
天文学家Greg Laughlin可以帮助大家设想一下， astronomer Greg Laughlin can help visualize
为什么彗星轨道，会在这颗路过的复仇女神这样的恒星 why cometary orbits are so vulnerable to the effects of a
影响下如此容易发生改变 passing star like Nemesis.
嗨，Greg Hey, Greg.
这位是Josh Horton，我们让他帮我们 This is Josh Horton, and we've enlisted Josh to kind of
理解奥尔特云的工作原理。 help us understand how the Oort Cloud really works.
你同时可以让多少颗球保持在空中？ How many balls are you actually able to keep up in the air at one time?
7个 That was seven.
8个或9个也可以做一小会， I can do a little bit of eight and nine, but seven is what I
但是7个做的最好 practice the most.
这种杂耍向上抛出的弧形 The arc of something that a juggler is tossing up is very
跟彗星在其偏心圆轨道的弧形非常的像。 much like the arc that a comet makes on its eccentric orbit.
特别是在快到顶部时，速度变慢， Especially because it's going slow near the top, and it's
在底部时速度变快 going very quickly near the bottom.
如果我们模拟整个奥尔特云， If we want to simulate the whole Oort Cloud, then we've gotta
我们就要更多的球在运动。 keep a lot of balls in motion.
我很想知道，如果你能很快的... So I'm wondering if you can maybe give me a quick--
好的，我试试 Yeah. Yeah, I can try.
从2个开始吧 Well, let's start with two.
2个球 Two balls.
如果你要做到这样，就要把它们 What you're gonna do here is you're gonna cross both balls in
扔到空中 the air.
开始扔了 So it's gonna be throw-- No.
这种投掷就像彗星的轨道一样 The throws are exactly the same,just like the path of a comet.
好，交叉，交叉 So...Cross, cross.
在空中作出x形状。 They're making an "X" in the air.
它们同时扔出去么？ 不是，是一下右一下左，抓住 - Do they leave at the same time or-- - No, it's right, left, catch,
抓住 catch.
右，左， - Right, left-- - No that was it.
开始扔的时候，你左手稍用点力 Just throw your left hand a little bit higher.
右，左，抓，抓。⊙﹏⊙ Right, left, catch, catch.
好的，然后抓住它们。 Good. You're kind of catching 'em at the same time.
右，左，抓，抓 Right, left, catch, catch.
好多了 That was better.
我做的有点类似太阳系了， So I'm a little bit like a Solar System where there's some
但就是混合着严重的引力不稳定。 serious gravitational instability in the mix.
Josh可以同时让7颗球呆在空中， So Josh is keeping seven balls in the air at the same time, and
那也不像太阳所做的那样，那是把数万亿颗 that's not unlike the Sun's job, which is to keep trillions of
奥尔特云中的彗星，围绕在自己周围。 comets all orbiting in the Oort Cloud.
但根据复仇女神的假设， But according to the Nemesis hypothesis,
太阳的精巧的杂耍会被打断 the Sun's delicate juggling act is disrupted by its
，被每隔2600万年出现的邪恶的恒星双胞胎打断 evil stellar twin every 26 million years.
就像一个恐怖电影，这个邪恶的双胞胎 And like something out of a horror movie, this evil twin
还看不见。 could be nearly invisible.
我们的太阳有这个双胞胎么？这个叫复仇女神的 Does our Sun have an evil twin? A star named "Nemesis" orbiting
轨道已经到了我们太阳系遥远的地方？ the distant reaches of our Solar System?
每2600万年，就会使奥尔特云中的彗星 And every 26 million years, does it fling comets from the
冲向地球么？ Oort Cloud toward Earth?
又时他们被抛出去，有时候它们的轨道 Sometimes they get tossed out, other times they orbit
会是无害的，知道它们最终蒸发掉。 harmlessly until they evaporate and go away.
如果有彗星通过内太阳系 If you have comets rattling through the inner Solar System,
那么，赌局开始了，胜负听天由命了。 then, in a sense, all bets are off.
科学家Richard Muller不仅建立了理论 Scientist Richard Muller not only theorizes
这种周期性毁灭是由 that this periodic mayhem is caused by a
太阳的死亡伴侣引起的，他还相信 deadly companion star to the Sun, he believes he knows
自己清晰的知道这种恒星的类型--红矮星。 precisely what kind of star it is-- A red dwarf.
距离太阳2600万光年， That there is a star orbiting the Sun in a 26-million-year
period，那是我的主意。 period, that was my idea.
我们假设恒星是一颗红矮星 Let's assume the star is a red dwarf star.
为什么是红矮星？ Why a red dwarf?
因为那是我们银河系里最大众的一种。 Because that's the most populist star in the galaxy.
红矮星很小，质量不到太阳的十分之一。 A red dwarf is a tiny star that weighs in with a mass less than 1/10 of our Sun.
但是天文学家Greg Laughlin证明， But as astronomer Greg Laughlin demonstrates, it can have the
它产生的影响，就像被扔进了保龄球座舱 effect of a 9-pod bowling ball tossed into the arms of a
像杂耍者在玩火把。 juggler playing with fire.
奥尔特云自身，是个无聊的地方，所以 All by itself, the Oort Cloud is a pretty boring place, and so
我们得提高点赌注了。 we're gonna have to up the ante a little bit.
这些都代表奥尔特云中的彗星。 These are gonna represent the comets in the Oort Cloud.
准备好了吗？ Are you ready?
我想我最好退后点。 I think I'm gonna step back a little bit.
Josh正顺利的抛着这些火把， So Josh has got them all going nicely,
就在在奥尔特云中的彗星 just like the comets orbiting in the Oort Cloud.
让我们看看，如果红矮星被抛进 So let's see what would happen if I took this red dwarf and
太阳系，会发生什么状况。 tossed it into the Solar System.
Josh，准备好了么？我要把这个红矮星跑进去了， Josh, are you ready for the red dwarf?
好的， Yeah.
来啦。 Here we go.
哦！ Oh!
你能看到，这颗红矮星通过了太阳系 So as you can see, the red dwarf coming through the solar
真的会改变彗星的轨道。 system has really changed the orbits of the comets.
注意看，这2颗彗星，撞到了地球了。 Notice that two of these comets actually crashed onto the earth.
那跟巨大天体造成的影响可不一样， That's not unlike what happens when a giant impact occurs, and
我们会大规模的被消灭。 we get one of these mass extinctions.
许多人认为地球 For many people the idea that Earth has been
成为这颗围绕太阳的死星 the victim of a series of impacts caused by
的牺牲品的想法不太可能。 an orbiting death star seems unlikely.
毕竟，当我们望向天空，只能看见我们的太阳。 After all, when we look at the sky, we only see one sun.
事实上，大多数的恒星都是成对出现的。 But in fact, the majority of stars come in pairs.
差不多百分之60到70的是双星系恒星 Probably something like 60%, 70% of stars may indeed be
甚至还有更多的 binary, or have even higher
恒星在其系统中。 numbers of stars in the system.
Richard Muller's的复仇女神的理论， According to Richard Muller's Nemesis hypothesis,
我们的太阳就是这种双星系统的其中之一。 our Sun is part of such a binary star system.
我的工作 It all works.
就是去假定我们的太阳， All you have to do is hypothesize that the Sun, like
像我们星系里其他的三分之二的恒星一样，有这样的伴星... 2/3 of all the other stars in the galaxy, has a companion--
在距离2600万光年远的地方，存在这这颗伴星。 This one with a 26-million-year period-- And there you have it.
但假如真有，为什么在天上看不到这颗伴星呢？ But if so, why don't we see the Sun's twin in the sky?
按照Muller所说，原因很简单。 According to Muller, the reason is simple.
这颗伴星是一颗非常暗的红矮星。 Nemesis is an extremely dim red dwarf.
当我第一次提出复仇女神星理论的时候，就有争议， When I first came up with the Nemesis theory, the issue was,
等一下，为什么没人发现它？ "well, wait a minute, how come nobody found it?"
很简单， And that was pretty obvious.
它很难被发现。 It has to be hard to find.
红矮星发出的光很微弱。 By definition, a red dwarf barely glows at all.
它是距离地球最近的恒星，但我们 It would be the closest star to our Sun, and we wouldn't
甚至还不知道它。 even know it.
为什么呢 Now, why is that?
我们能发现邻近的恒星的原因之一，是， The way we discover nearby stars is either because they're very
它们非常亮，红矮星却很暗.. bright-- And the red dwarf star is not very bright--
或者因为太阳正朝它移动。 Or because the Sun is moving past it.
这颗红矮星正朝我们而来 This star is moving with us.
是的，它正朝我们来，但是它的轨道运动很慢，要2600万年， Yes, it's orbiting us, but that orbit is very slow-- 26-million years.
就像与我们的太阳一起运转。 So it'd be moving with us.
就像呆在天空一个固定的位置，没有移动一样 It would just be at a fixed position in the sky, and wouldn't move.
也就是说，从地球上看，大多数天体 In other words, when viewed from Earth, most nearby objects
都在随时间推移，在运动着。 are shifting over time.
但是复仇女神就在那里， But Nemesis is sitting still.
要找到这个复仇女神的位置 So as the search for Nemesis enters high gear, one key
关键问题是在哪找。 question is where to look.
很幸运，科学家们知道双星体统的轨道运行方式 Luckily, scientists understand how binary stars orbit each
他们可以把这些知识应用到寻找复仇女神上。 other, and they can apply this knowledge to the search for Nemesis.
如果太阳跟它的伴星质量相同， If both the Sun and Nemesis were of equal mass, they would orbit
它们的轨道虽宽但却很圆， each other in a vast but equal circle, and the search for
那找到这颗伴星就相当容易了。 Nemesis would be relatively easy.
但很少有同样大小的双星 But binary stars are rarely equally sized.
只有百分之10到20的双星系统的恒星 10% or 20% of binary stars have two components where the
大小相当， stars are really on an equal footing.
大部分的系统中的恒星，都是一颗恒星 And then there are also a large number of stars where one star
的质量比另一颗大很多。 is considerably more massive than the other.
当双星系里的恒星大小不同时，小一点的 When binary stars are of different sizes, the smaller
恒星，就如那颗复仇女神星，会以一个大轨道 star, in this case Nemesis, swings in a wide orbit around
围绕着质量大的伴星，就是我们的太阳， its larger companion, in this case the Sun, which barely seems to orbit at all.
为什么那个小的恒星会有那么大的轨道？ Why does the smaller one move in a much wider circle?
回答这个为题就要说到一种概念叫“质量中心” The answer has to do with a concept called the "center of mass."
这两个在平衡木上的体操运动员，能帮助我们设想那是如何运作的。 A pair of gymnasts on a balance beam can help us visualize how it works.
双星系统中的恒星围绕着它们的质量中心。 Stars in a binary pair orbit around their common center of mass.
如果两颗恒星质量相同，它们会围绕着 If two stars are about the same mass, they orbit around an
一个看不见的点，就在它们的正中心 invisible spot in the middle, right in between the two of
就像Tami和Carly在这个跷跷板上一样。 them, just like Tami and Carly are balanced on this seesaw.
跟这两个体操运动员不同的是，复仇女神和太阳质量不同 But unlike these gymnasts, Nemesis and the Sun are not equal.
天文学家Richard Muller估计，太阳要比 Astronomer Richard Muller estimates that the Sun has ten
它的伴星大10多倍。 times more mass than its undiscovered twin.
当其中的一个比另一个大的时候， And when one binary star is larger than its sibling, the
质量中心就要转移到靠近大恒星的位置。 center of mass between them shifts closer to the larger star.
Tami要演示一下。 So Tami's going to help illustrate that.
Tami，你体重是多少 Tami, how much do you weigh?
大约130磅 About 130.
约130磅？ About 130?
在这边我们放了大约35磅的砝码， And we have weights at this end that are about 35 pounds.
不到你体重的四分之一。 So you're just a little bit less than four times that weight.
那么爬上去， So climb on up.
让我们看看在哪是这个平衡点 Let's see where you have to be to balance the balance beam.
tami的体重是砝码的四倍 Since tami weighs about four times as much as the metal
她必须要靠近质量中心以达到平衡。 weights, she must move far closer to the center of mass to maintain balance.
如果tami和砝码代表双星系统， If tami and the weights represented binary stars, the
当tami移动时，砝码的轨道就会在很远的距离。 weights would orbit far out in the distance while tami would barely move.
实际上，它们在相互玩绕。 In fact, both would be orbiting each other.
有一种误解认为，大质量的这颗恒星没有动 It's kind of a misconception to think that the more massive
只是小质量的恒星在绕着大的转。 star doesn't move, and the less massive star just goes around it.
实际上，它们同时在绕着一个质量中心旋转。 In fact, they're still both orbiting the common center of mass.
大质量的恒星移动的相对慢一点 The more massive star moves less,
质量小的恒星移动速度慢一点。 and the less massive star moves more.
这种见解是计算太阳跟复仇女神 This insight is key to calculating where
位置关系的关键 Nemesis might lie in relation to the Sun.
复仇女神有2600万光年那么远 We know it's a 26-million-year period.
那就是离我们的距离。 That tells us how far out it is.
可以知道太阳的轨道大小 It has a radius of about a little over a light year.
半径就有约一光年。 So we know the orbital size.
现在科学家知道，大致在哪里找它了， Now that scientists know roughly where to look, the
并且正在尽全力寻找着它。 search for Nemesis is in full swing.
到目前为止，寻找到了这样一个惊人的新理论。 And so far, that search has led to an astounding new theory.
不仅太阳有这样一个未被发现的伴星， Not only might the Sun have an undiscovered twin, the solar
而且太阳系中 system may be harboring a
还有大量未被发现的行星。 massive undiscovered planet.
寻找这个邪恶的伴星 In the hunt for an evil twin to our Sun that
那些松散彗星的死亡之雨横穿 shakes comets loose and rains death across the
地球，除了一个地方其他都要受到影响。 Earth, all of the pieces are in place except one.
复仇女神理论需要有力的证据， The Nemesis theory really needs the smoking gun of
需要发现直接的证据，才能把 actually finding direct evidence for the object itself in order
让人们接受。 for the whole thing to hold together.
为什么还没发现它？ Now, why haven't we found it yet?
实际上，有不少天文学家 Actually, there are quite a few astronomers who don't pay very
并不太重视这个，仅仅认为它可能存在 much attention to this, and simply assume that if it
至少到目前还没发现。 existed, it would have been found by now.
我们相信在未来几年，能找到它。 We believe this thing can be found within the next few years.
找到这颗黯淡的恒星。 What it takes is a survey of dim stars.
NASA的广域红外线巡天探测卫星，简称WISE Enter WISE, the orbiting "wide-field infrared survey explorer,"
一个强有力的工具，有可能破解复仇女神星的秘密。 a powerful new tool that just might crack the Nemesis mystery.
这个探测器优秀的原因 The reason that WISE is gonna be so good is because it
是因为它可以探测3至25微米的波长红外线。 operates in the infrared.
它能探测热辐射。 It sees heat, basically.
通过测量热而不是光， By measuring heat instead of light, infrared scanners
探测器可以更容易的扫描到温暖而黑暗的天体。 can make warm but dark objects easy to spot.
它最妙的地方就是可以探测各种红外线 The nice thing about looking in the infrared at the heat of
而不用担心离我们有多远。 it is you don't care how far away you are from the Sun.
以木星为例。 Jupiter provides an example.
木星表面的温度 The temperature on the surface of Jupiter measures 230
是零下230华氏度（摄氏零下110°） degrees below zero fahrenheit.
但相比外层空间的零下450华氏度来讲 But that's blazing hot when contrasted with the 450-degree-below-zero
温度还算是高的 temperature of space.
所以即使缺少光照的地方，类似木星的地方 So even in the absence of sunlight, a distant, Jupiter-like planet would glow
也可以发出明亮的红外线。 brightly in the infrared.
来到这个赛车道，我们就能知道 By visiting a motor speedway, we can see how the WISE
也许能通过对比天体的不同温度 survey might help find Nemesis by exploiting the infrared
发出的红外线找到那颗复仇女神星。 contrast between objects of different temperatures.
在这里，引擎轰鸣声只讲了故事的一半 Here, the roar of the engine only tells half the story.
我今天来这里， I came out here today to the drive tech racing school to be
要进到一辆赛车里，绕着赛道跑几圈。 in a race car that would go zooming around this track a bunch of times.
我们的想法是，利用一部红外摄像机，拍摄这部车 An idea was to film the car with an infrared camera,
来告诉我们一些事情-- and show us things that are hot--
跟外部环境比，哪个地方更热-- Hotter than the outside surroundings--
看一下红外波长发出的光。 And glowing at infrared wavelengths.
你好，Ted， - So, hey Ted! - How you doing?
很高兴见到你， Good to meet you.
我也是。 Likewise.
好的，你就是驾驶员么？ Yeah. You're the driver?
是的。 Yes, sir.
我们会跑多快？ Now, how fast are we gonna be going?
大约时速170英里吧 Approximately 170 miles an hour.
那差不多是正常公路速度的3倍， Now, that's about three times normal highway driving speed, so
真让人期待呀 whoa, things are really gonna heat up.
是啊 Oh, yeah.
好吧，出发！ All right, let's go, then.
驾驶教练Blair Dupree会帮助我进入赛车。 Blair Dupree of drive tech helped me get into the car.
要保护好 Good protection.
这是个漂亮的厚厚的头盔。 This is a nice, thick helmet.
很不容易进去，因为这车没有门， And it's not so easy, because there's no doors, okay.
你要从车窗爬进去。 You have to kind of climb in through a window.
这只脚放这里 Bring your left foot up in there.
好 Okay.
这只脚抬起来。 Bring your right foot on up.
我感觉像被硬塞进车里的。 I feel like I'm breaking into a car.
也只有这种方法。 And then kind of slither your way in.
能进入这样的赛车里真让人兴奋。 Being in that race car was really exciting.
当我绕圈时，能感觉到身上被施加的重力。 When I was going around the turns, I could really feel the g-forces.
Ted开的不错，是吧 Ted give you a good ride, did he?
哦，是的，很不错 Yeah, well, I'm glad Ted was the driver.
我不能做这个，你知道吗？ I couldn't do this, you know?
我都没开车，还被吓得几乎站不起来了 I was scared out of my seat, and I wasn't even the driver, okay?
随着车辆的变热，一部前置红外摄影机， With the car nicely warmed, a FLIR infrared camera, set up
正在热成像专家的 Ross Overstreet操控下，注视这一切， by thermal-imaging expert Ross Overstreet, sees everything,
逐渐地，新的光线出现了。 literally, in a new light.
你好， Alex Hello, Alex.
嘿，Ross，你好 Hey, Ross, how you doing?
情况咋样？ Doing good. How you doing?
很好， Good, good.
让我们看看这些红外图像 Let's look at these infrared images.
看这儿，我们正拍摄车的后面。 Right now we're pointed at the back of the car.
这样的测量装置真不错， The best way to think about it is it's more of a measurement
比照相机强。 device than a camera.
这张图上，就像有百万种不同的温度一样。 It's like having a million different thermometers spread across the image.
这些图像就是我们得到的温度图了。 We're actually getting temperature measurements on each of those pixels.
这些地方温度高，颜色是这些 Things that are supposed to be hot look like they're glowing
橘红色的跟白色的区域 red and orange and white.
温度低的区域，颜色就是蓝色跟黑色的。 Things that are cold are colored blue and black.
你试想一下物体的冷色调。 You know, colors you associate with cool objects.
对 Right.
你会看到这部车上有几个不同的热区。 And you'll notice there's several different hot areas of the vehicle.
我看到轮胎上有些变化， Now, I see some variations across the tires.
你会看到其中一只轮胎的温度 Yeah, and you'll notice that the one tire is a little bit
比另一个低一点。 warmer than the other.
右边的轮胎温度高于左边的这个 The right-hand tire was indeed hotter than the left-hand
是因为在行使期间轮胎压力更高。 tire because there was more pressure on it during the turns.
能高多少度？ So how hot is that hotter tire there?
我们测量过，差不多190华氏度（摄氏87°） We made a measurement earlier of about 190 degrees fahrenheit.
那几乎跟开水的温度差不多了。 Almost the temperature of boiling water on the tires.
哇 Wow.
只用肉眼看，我们不可能知道 When we just look by eye, we can't tell whether something is
哪里温度更高。 hotter than something else.
但有这个就可以啦，真酷。 But here you can tell, and that's really cool.
对，这种摄像机， Right. And this camera would work just as well if it was
在暗处或晚上工作最好了。 pitch black or in the middle of the day.
它基本不需要阳光。 It doesn't care about solar light at all.
这部红外摄像机运作的方式 The infrared camera sees the racetrack the way the WISE
就像NASA的WISE探测着太阳系遥远的深空。 survey scans the dark and far-away realms of our Solar System.
如果复仇女神星在那里，红外线就能揭示它。 If Nemesis is out there, infrared should reveal it.
车上的热的区域，就像 The hot spots on the race car are sort of like warm, glowing
是远离太阳的，寒冷太空中的天体。 objects out in the cold depths of space, far from the Sun.
用这种全新的方法去探测天体， This is a whole new way of discovering objects-- Objects too faint to be seen
用普通望远镜看不到的黯淡的天体 through a normal optical telescope, but bright enough to
但用红外探测器却可以。 be detected in the infrared.
WISE在2011年能完成探测任务 The wise telescope completed its sky survey in early 2011, but in the search
但到目前为止，还没发现复仇女神星。 for Nemesis, the results are still inconclusive.
这部红外探测器要花很长时间去分析， The WISE survey is going to take a long time to analyze,
因为它收集到的数据 simply because there's a huge amount of data that had been
十分的庞大。 gathered by this craft.
About half of the Nemesis candidates have not yet been studied.
在接下来的几年，我们希望这种理论 But in the next few years, we expect the theory will be either
能被证明是错误的。 proven right or wrong.
直到那时，争论才能停止。 Until that time, it is and should be controversial.
“这种模糊不清的接近地球的东西到底是什么“？ That something so relatively near to Earth can be so obscure
来自亚拉巴马州莫比尔的Frank Jankowski问宇宙节目 is what Frank Jankowski of Mobile, Alabama, wants to ask The Universe.
为什么科学家们能观察到几百万光年远的物体，却看不到太阳系 边上的物体？
很有趣的问题，Frank That's an interesting question, Frank.
几百万光年远的天体被科学家看到 The objects that are millions of light years away that
是因为它们能发出强光。 astronomers can see are powerful and luminous.
它们能产生大量的能量，像是爆炸中的恒星。 They produce a lot of energy on their own, like an exploding star.
但是太阳系边上的天体都很小 But an object near the edge of our Solar System might be small,
只能接收到微量的光照， and it reflects only a little bit of sunlight, so we can't see
在可见光的波段我们看不到他们。 it at visible wavelengths.
科学家们分析符合复仇女神行的数据， But scientist analyzed the data for signs of Nemesis,
他们有了一个令人不安的发现 they have made a disturbing discovery.
虽然计算表明，复仇女神星 Although calculations indicate that Nemesis isn't due back for
要几百万年后才能返回，但还是 millions of years, something appears to be shaking up the
出现了一些事情，扰动了奥尔特云中的彗星。 comets in the oort cloud right now.
难道复仇女神在迫近我们？ Could Nemesis already be upon us?
当复仇女神星理论开始出现，科学家们就密切注意着 Since the birth of the Nemesis hypothesis, astronomers have been on the lookout for a
那些被暗淡的红矮星，些被周期性的引力打扰 faint red star that periodically disturbs the gravitation of the
的奥尔特云中的彗星。 Oort Cloud comets.
在内太阳系，它们会有灾难性的交会， This sends them on a catastrophic rendezvous with the inner Solar System,
包括地球在内，每隔2600万年。 including Earth, every 26 million years.
但当科学家们研究奥尔特云时， But as scientists study the Oort Cloud, they have uncovered
他们发现了令人不安的证据，有些东西正干扰着奥尔特云中的彗星 unsettling evidence that something is disturbing comet orbits right now.
复仇女神回来了？ Has Nemesis already returned?
如果太阳只有自己，没有伴星， If the Sun was all by itself, and there was no Nemesis, then
奥尔特云中的彗星 the comets in the Oort Cloud would all have very predictable
都应该老老实实的呆在那里。 and regular orbits.
它们到达出发的时间都应很有规律。 They'd be very regular in their arrival times and departure times.
如果太阳没有任何其他引力干扰， Without gravitational interference from anything other
奥尔特云中的彗星，就像杂耍者手中的玩意， than the Sun, Oort Cloud comets, like juggled objects, could
均匀的在空中运动着 spread out evenly across the sky.
然而，这不是一些科学家报告 However, that's not what some scientists report.
当我们望向天空，看看 When we look out into the sky, and look at where the
彗星从哪来？它们往往集中在 comets are coming from, their directions tend to concentrate
天空中的某些区域。 in a certain region of the sky.
有一个可能的解释是，这种偏移是由于 And one possible explanation for that is that that skew is being
从我们看不见的一个物体上发出的， directed by the gravitational perturbations from an unseen
引力扰动所导致的 object that is out there.
在这些意见的基础上，科学家们推断 Based on these observations, scientists infer that a huge
有一个巨大的天体在干扰着奥尔特云。 object is disturbing the Oort Cloud.
在他们研究这些的同时，加利福尼亚运输官员 They do this the same way that California transit officials
在洛杉矶，推论着一起事故扰乱交通的模式。 infer that an accident is disturbing traffic patterns in Los Angeles.
Marco，我们在哪？ So, Marco, where are we?
这是什么？ What is this room?
哦，墙上的这些图，是高速路系统图像 Well, the map we have here on the wall, that's our freeway system map.
如你所见，它显示的是洛杉矶的主要路线。 And as you can see, it shows the major freeway routes in Los Angeles.
这些绿点，代表的是正常的车辆流量 The green dots represent normal traffic flow, while the
红点代表 red dots indicate that something
有些事引起了交通拥挤。 is causing traffic to back up.
这里的速度显示 So the speed here's just one indicator
只是显示出是否拥堵，但如果想知道 that something's going on, but to really know what's
哪儿发生了什么，还需要监控或 going on, you either have to have a camera or a report from
人员的报告，才能知道具体发生了什么状况 somebody who's actually there and able to tell you what it is.
对 That's correct.
天文学家也面临这种问题， Astronomers have this problem all the time,
他们试着去了解他们看不到的东西。 they're trying to understand what they can't actually see.
在天文学上，会经常推断一些存在的东西， In astronomy, we frequently infer the existence of something, not because we can
不是因为我们能看见它们，是我们 actually see it, but because we can see the influence it has
能看到物体对它造成的影响。 on the objects around it.
除非是车太多，车道太少 Whether too many cars or crowding too few lanes during rush hour, or an accident is
或是事故，才能引起交通拥堵。 slowing traffic flow, something causes congestion.
由于科学家们在奥尔特云中看到了类似的拥堵， Since scientists see similar congestion in the Oort Cloud, could Nemesis be the
复仇女神星会是犯罪者么? perpetrator?
这地方让人印象深刻 This place is very impressive.
有很多监控跟传感器， It's got all the cameras, all the sensor data, all the
能知道全加州的公路状况。 California highway patrol incident reports.
他们的数据比天文学家得到的数据要多 This is far more data than astronomers have to work with.
如果我们也有摄像机遍布在太阳系外 If we only had remote cameras all throughout the outskirts of
我们也可以知道的更多 the Solar System, we might know a lot more about it.
即使没有那样的摄像机，科学家们也有一个很不错的理论 Even without remote cameras, scientists have proposed a remarkable theory to
来解释奥尔特云中的拥堵。 explain the congestion in the Oort Cloud.
那就是，导致彗星紊乱的不是复仇女神星。 According to this theory, the culprit disturbing the Oort Cloud isn't Nemesis.
也同样令人震惊--一个巨大的未被发现的--行星， Instead, it's something equally astounding-- A giant, undiscovered planet,
比木星质量还要大四倍。 four times the mass of Jupiter.
很意外，我们太阳系还有这样大的行星。 In short, the largest planet in the Solar System.
科学家们提议给它取名Tyche Scientists have proposed naming it Tyche.
简而言之，Tyche名自希腊神话中的命运女神 In a nutshell, Tyche is "Nemesis light."
复仇女神星，原本是一颗红矮星。 Nemesis, in the original hypothesis, was literally a red dwarf star.
要比木星大100倍。 Something that was 100 times more massive than Jupiter.
不像复仇女神星，Tyche不像太阳一样发光。 Unlike Nemesis, Tyche would not glow like a star.
它就像一个奇怪版本的木星。 Instead, it would look like a strange version of Jupiter.
如果你带上夜视眼睛 If you put on night-vision goggles, then it would be quite
会有不同的视野。 a bit more impressive sight.
你能看到云的裂缝，也许会有闪电 You would see breaks in the clouds, and there would be lightning.
你能看见闪电 You would see the clouds light up from the lightning down
在云中闪耀着 beneath the cloud tops.
Tyche影响到了奥尔特云中的彗星轨道 Tyche might disturb the orbit of comets in the Oort Cloud,
但它不是地球周期性毁灭的源头 but it can't be the source of Earth's periodic extinctions.
首先，它的轨道在一百万光年远的地方 First, its proposed position puts it on a 1-million-year
不像复仇女神星的2600万光年那么远 orbit, not 26 million, like Nemesis.
第二它太小了 Second, it's too small.
Tyche没有足够的引力逐出彗星， Tyche doesn't really have the gravitational mojo to dislodge
造成这种周期性的灭绝-- comets, send them crashing in in these periodic extinctions--
并重新排列奥尔特云的布局。 Really rearrange the Oort Cloud.
它的影响显而易见的只是些小的 And so it's effects would be visible only in these small
彗星，并不能引起那种大彗星 skews, and not in the form of huge pulses of comets coming out
的轨道波动。 of seemingly nowhere.
就像复仇女神星，NASA的WISE探测器 Just as with Nemesis, NASA's WISE survey should be able
应该能发现它，如果它真的存在 to detect Tyche, if it exists.
而奇怪的是，我们的太阳系是一个巨大的避风港 While it's surprising that our Solar System might harbor a
庇护这些未被发现的行星， giant, undiscovered planet, it doesn't support or refute the
也庇护着那个未被探知的复仇女神星。 idea that it also harbors the undiscovered star Nemesis.
但最近的发现却阐明了 But a recent finding in the outer Solar System may shed more
这种死亡伴星是否真的存在， light on whether Nemesis really exists, and the kind of threat
并威胁着地球上的生命 it may pose to life on Earth.
2003年，天文学家Mike Brown历史性的发现 In 2003, astronomer Mike Brown made an historic discovery when
太空中漂浮着一颗他不能解释的天体。 he found something floating around the night sky he couldn't explain.
我仍然记得发现Sedna的那一天。 I remember the day that I discovered Sedna.
我看着我的电脑屏幕， Looking at it on my computer screen, looking at these
看着这些图像，我第一个反映就是“那不可能” pictures, my first reaction was "that can't be real."
它太远了。 It's too far away.
在太阳系那么远的地方，应该没有东西存在 Nothing like that exists in the Solar System.
他偶然发现了一个比月球还小的行星， What he stumbled upon turned out to be a planetoid just smaller than our moon,
就是这个矮行星Sedna now named Sedna.
但Sedna却提出一个科学的困扰。 But Sedna presents a scientific quandary.
它最近的距离，也要比冥王星到太阳的距离远3倍 At its nearest point, Sedna lies about three times farther away
在这一区域，天文学家从未 from the Sun than Pluto, in a region where astronomers never
指望能发现行星的踪迹。 expected to find planetary bodies.
在我们太阳系最冷最远的地方。 It's the coldest, most distant place that we know in the whole Solar System.
如果你站在在Sedna的表面， If you were sitting on the surface of Sedna, you could take
把一个大头针，拿在手中，伸到前方 a straight pin and hold it out at arm's length, and with the
就可以盖住远处的太阳。 head of that pin, you could cover up the Sun.
Sedna除了在一个遥远的地方， In addition to being in an unexpectedly distant region,
还有一个巨大的椭圆轨道围绕着太阳系。 Sedna also takes a wildly elliptical orbit through the Solar System.
神秘的是Sedna周围什么也没有 The mystery is there's nothing anywhere near Sedna that could
说明它的轨道真的十分遥远。 account for an orbit that distant and that extreme.
那个地方，对我们没有任何影响。 The place where it is now, nothing ever affects it.
它没靠近任何行星， It doesn't come close to any planets, there are no stars that
也没有任何恒星靠近过它。 ever come close to it.
什么使Sedna进入如此独特的轨道？ So what forced Sedna into its unique orbit?
复活女神星，也对其产生影响了吗？ And in theory, could the death star Nemesis have played a role?
Brown，在蹦床上的表演， For Brown, the bounce of a trampoline offers a way to
可以提供一种方法让我们理解 understand how Sedna ended up in an orbit that remains a
Sedna的轨道状态，这个让天文学家头疼的问题 head-scratcher for astronomers.
在我背后有一个测量棒， I have behind me a measuring stick that gives how high I'm
2英尺一个的间距。 gonna bounce in 2-foot intervals you see here.
我跳起来的距离假定就是我距离太阳有多远 And what that bounce is supposed to represent is how far away
从太阳到我所在的轨道 from the Sun I am in my orbit.
一颗正常行星的轨道，都是圆形的 In a normal planetary orbit, in a circular planetary orbit, the
围绕着太阳，一直都差不多是同样的距离。 planet circles around the Sun, always staying the same distance from the Sun.
就像我在这个蹦床上，一直 And that's sort of like me staying on a trampoline, always
跟床面保持着同样的距离。 the same distance from the floor.
有些行星的轨道，不是圆的 Other sorts of orbits can be, instead of going in a circular
是以椭圆轨道围绕太阳运行。 orbit, you can go in an elliptical orbit around the Sun.
远离太阳，再回来。 You move away from the Sun, you come back towards the Sun.
会走的很远，在离的很近。 And so you'll be moving further away and getting closer.
我开始在蹦床上跳上跳下。 And that would be starting to jump up and down on the trampoline.
就像引力把我牵引在轨道里， Like gravity keeping us in orbit, when we reach the apex
当我到达了顶点，引力会使我向下。 on the trampoline, gravity will pull us back down.
什么事也不会发生的 So as long as nothing happens to me, I stay in this orbit
我永远在这上，下，永远都是这个高度。 forever, jumping up and down, always to the same height.
但有些不寻常的事困扰着Sedna But something unusual afflicted Sedna.
它碰到一个神秘的力量，把它 It brushed up against a mysterious force that shoved it
推进一个行星不应该存在的地带。 into a region where no planetary body should exist.
据猜测可能就是复仇女神星。 Some suspect that force was Nemesis.
如果太阳的邪恶伴星就在那外面 And if the Sun's evil twin is out there, scientists can tell
科学家们就可以确信的说 我们什么时候会知道它有返回的迹象 exactly when we'll see the terrifying signs of its return.
当天文学家在寻找这颗死亡之星 As astronomers search for a death star named Nemesis
这个可能引起地球 that might periodically cause mass
周期性毁灭的恒星时，最近发现的这个小小的世界 extinctions on Earth, the recent discovery of a tiny world named
这个小小的世界Sedna可能是证明其存在的关键。 Sedna could prove key.
十几亿年前，Sedna围绕着太阳旋转 Billions of years ago, Sedna revolved around our Sun, like
以一种近圆形的轨道，就像其他行星一样，。 other planets, in a nearly circular orbit.
然后发生了两件奇怪的事， But then two strange things happened.
首先，有些东西把Sedna推进了一个极为椭圆的轨道中。 First, something forced Sedna into an extremely elliptical orbit.
然后有些东西把它推向遥远的地方 And then something else pushed that orbit out so far that it
这种原因的解释不太明晰。 seems to defy any visible explanation.
第一个问题--让它轨道变椭圆的是什么 The first question-- What caused it's elliptical orbit--
很容易解释 Is fairly easily explained.
它可以被太阳系外围的气体巨型 It could simply have been gravitational tugs from the
木星和土星的引力牵引着。 outer gas giants Jupiter and Saturn.
蹦床可以帮助说明 A trampoline can help illustrate.
为了更好理解太阳系里行星的轨道， To really understand how orbits in the Solar System work
如何变椭圆的轨道，我们要 and we get these very elliptical orbits, we need to get more
在蹦床上蹦的更高。 height on the trampoline.
我能做到，Ken，你能帮我一下么 And I can't do it, so, Ken, I'm gonna need your help.
好的，我可以帮忙。好，我下去。 - Well, awesome, I' ready to help. - Let me get out of your way.
就如这个帮忙的人，可以让第一个人蹦得更高， Just as extra people on a trampoline create extra bounce,
太阳系的气体巨星也可以制造足够的 the large gas giants in the Solar System can create enough
引力把一颗小行星的轨道拉成椭圆。 gravitational bounce to stretch a smaller body's orbit into a wide ellipse.
所以Sedna就有了一个漂亮的椭圆轨道了。 So here's Sedna on a nice elliptical orbit.
当Sedna试图接近其中的一颗行星时， But then Sedna got a little bit close to one of the planets.
行星的额外附加引力 As soon as it does that, the extra gravity of the planet
就会把它的轨道一点点加至椭圆。 gives it a little boost into an even more elliptical orbit.
但当它接近另一颗行星时，我们说的是木星 But then it gets close to another planet-- Let's say Jupiter.
木星来了 Here comes Jupiter.
他能弹的更高。 It bounces even higher.
从木星得到更多的外力， With enough bouncing from Jupiter, we could bounce Sedna
Sedna就被推到遥远的外太阳系里了。 all of the way out of the Solar System.
被木星土星的引力轨道反弹 The orbital bounce provided by Jupiter and Saturn can
可以解释Sedna的轨道成椭圆的样子， explain how Sedna's orbit got its elliptical shape, but not
但如何最终被迫到了一个 how it ended up being forced into a distant region of the
太阳系的遥远区域，那样的科学家从未发现有其他行星的区域 Solar System, where scientists never expected to find a planetary body.
Sedna有一个椭圆的轨道，距离十分十分的遥远 Sedna was on an elliptical orbit, getting further and further and further.
一定有什么使它走的那么遥远。 And then something happened to it when it was out here.
一定有其他的引力把它推入这种特殊的轨道， Some other gravitational force pushed it off into a different
让它不会再回到它之前所在的位置了。 orbit, and so it didn't come back to the same place it was before.
有第二种引力把Sedna推挤到 It's as if some second gravitational force was passing by and shoved Sedna onto a
不同的轨道，被弹射到一个出乎意料的区域。 different trampoline, so that it bounces in an unexpected region.
最有可能的答案就是有另一颗恒星 The most likely answer is that there was another star
非常非常接近太阳，当Sedna very, very close to the Sun at the time when Sedna was going
轨道在变椭圆的同时 through this process.
太阳系可能形成与星团之中， The Solar System probably formed in a cluster of stars,
有可能跟邻近的恒星亲密接触到， and so close encounters with nearby stars, nearby rogue
甚至是附近的行星，这在太阳系形成早期 planets even, were much more common during the very earliest
是比较常见的 days of the Solar System's formation.
大多数这些太阳的姊妹都很分散。 Most of these solar brothers and sisters have long since dispersed.
但根据复仇女神理论，其中有一个恒星 But according to the Nemesis hypothesis, one of them is still
还呆在外面，仍围绕着太阳， out there, still circling the Sun, still causing periodic
仍然引起彗星的周期性混乱 chaos amongst the comets, and still waiting to rain death
仍然在等待带给地球彗星撞击之灾。 on the Earth once more.
如果那是真的，未来的人们将要面对 If that is correct, future generations will be faced with a
一个巨大的威胁，当复仇女神到来的时刻.... monumental threat when Nemesis returns...
在1000万年以后 In 10 million years.
月球，火星，这些行星 The Moon, Mars, the planets would basically be unaltered
基本上跟现在比没什么变化 from their current condition.
在地球上，城市可能不在那儿了， On Earth, cities might not be there, but the continents would
但是大陆的位置 still be almost in exactly the
几乎没有改变。 same places that they are now.
但是复仇女神的理论说， But according to the Nemesis hypothesis,
距离太阳一光年的位置会有比较大的改变。 a major change is underway one light year from the Sun.
一颗暗红的恒星会进入到奥尔特云中。 A dark-reddish star has entered the Oort Cloud.
复仇女神回来了 Nemesis has returned.
如果地球上仍然有人类 If humans still exist on Earth, they'll face a slow-building but
他们将要面对这个进度缓慢但迫在眉睫的宇宙威胁。 imminent cosmic threat.
奥尔特云中包含了10亿颗彗星，甚至更多。 The Oort Cloud contains perhaps 10 trillion comets, maybe even more.
它真的很辽阔 But remember, it's really big.
如果你在奥尔特云里 So if you were in the Oort Cloud,
你不会遭到彗星的持续打击。 it's not like you would be pelted by comets all the time.
它们之间的空间太大了。 The spaces between them would pretty big.
就像杂耍着手中的瓶子， Like a bowling ball in a juggler's hands,
复仇女神只会影响到一部分的彗星的方向。 Nemesis simply shuffles some comets out of its way.
奥尔特云中间有一个空的区域。 The Oort Cloud has an empty region in the middle.
那是被木星和太阳清理干净的。 It's been cleaned out by Jupiter and by the Sun.
我们生活在这一地区 We live in that region.
当复仇女神靠近时，内太阳系就会变成射击馆 But as Nemesis approaches, the inner Solar System becomes a shooting gallery.
于是就开始有一些彗星比平常多的， And so there would start to be a few more comets than usual,
突然的到来， and then, suddenly, there are just comets, comets coming all the time.
最多的时候，可能每年有1000颗到10000颗 And at the peak, there might be 1,000 to 10,000 comets per
彗星冲入内太阳系 year in the sky.
这样算来， According to the projections Earth would be
地球要当彗星的靶心，差不多100万年。 in the crosshairs of this comet storm for a million years.
这一百万年期间， Over a period of a million years, there would be visits by
地球得被十亿颗彗星拜访。 about a billion comets.
这样的概率，怎么说都得有至少一个或更多的 Actually, you do the calculation, it turns out one of them will hit the Earth.
彗星会撞到地球。 One or two.
很难准确的预测那种情况会发生， It'd be difficult to predict exactly when
但会有那一个时期的-- the impact would happen, but there would be this phase--
这种灾难影响的偶然区域 This sort of danger zone in which the chances for a catastrophic impact with
取决与彗星尺寸的大小， something of a comet's size would be much, much higher than they are now.
会有另一个毁灭地球的大灾难么？ Will the impact spark another catastrophic extinction on Earth?
也许 Perhaps.
如果它真的发生了 But only if we let it happen.
我宁可认为复仇女神星是一个玩笑。 I like to joke that Nemesis planned this one poorly.
在下次大灭绝之前，有大把的时间 In between the last extinction and the next one, there's plenty
让智慧生命做好准备 of time for intelligent life to get its act together to make
在复仇女神再次到来，并使彗星袭击地球之前 sure that next time Nemesis comes back and the sky is filled
确保不会让它们打到我们。 with comets, to make sure that none of them hit us.
未来，这是必然的么？ Is this future inevitable?
直到科学家们发现复仇女神之前， Until scientists either discover Nemesis or definitively rule it
没有人能确切的知道。 out, no one can know for sure.
重要的是要认识到这不仅是一个抽象的讨论 It's important to realize this is not just an abstract discussion.
显然，这些物体与地球相撞发生的情况，非常罕见 Clearly, these objects colliding with Earth happen very rarely.
但在另一方面，当他们碰撞时，就会引起惊天巨变。 But on the other hand, when they do collide, they're extremely cataclysmic.
所以，我们需要能够做的更好了解 So what we need to be able to do is get better understanding of
我们的太阳系，时刻注视天空， our Solar System, and keep an eye on the sky, because it may
那会对我们的生存很有帮助。 be crucial for our survival.
如果未来的某一天，天空充满了彗星， If the future sky one day does fill with comets, perhaps
也许，人类会找到一个办法 humanity will have found a way to save itself rather than end
远离这个是非之地，避免成为太阳那个邪恶同胞的牺牲品 up one more victim of the Sun's evil twin.