宇宙第六季第二集
太阳的邪恶双子星 :涅墨西斯 Nemesis...The Sun's evil twin
上溯至宇宙初始 周遭还只是一片漆黑 In the beginning, there was darkness,
不知何时 忽地一声巨响 and then--Bang--giving birth to
时间空间以及物质皆由此发端 an endless expanding existence
此后不断膨胀 延伸 永无止境 of time, space, and matter.
每一天 新的发现都在不断为我们解开 Every day, new discoveries are unlocking
蕴藏于这里的那些神秘莫测 the mysterious, the mind-blowing,
令人大开眼界 致命的秘密 the deadly secrets of
我们称这个地方为"宇宙" a place we call the universe.
我们的太阳是否有一颗邪恶伴星呢 Could our Sun have an evil companion?
是否有这样一颗未被发现的死星 An undiscovered death star
在最遥远的太阳系边界处旋转 徘徊 rotating at the furthest edges of the Solar System?
这颗神秘的恒星是否每隔一段时间 Does this mysterious star scatter destruction
就为太阳系埋带来毁灭性的灾难 through the Solar System at regular intervals,
它是否造成了地球史上最大规模的灭绝呢 accounting for the greatest extinctions in Earth's history?
科学家敏锐的目光穿过这个充斥着巨恒星 Sifting through a realm populated by giant worlds
以及神秘的小恒星的地带 去搜寻 and mysterious planetoids, scientists are on the hunt
太阳的邪恶双子星 涅墨西斯 for Nemesis...The Sun's evil twin.
我们头顶上闪烁的数以亿万计的群星之中 Of the billions of stars twinkling overhead,
有一颗也许会使地球上生灵涂炭 one may be a scourge to life on Earth...
它就是太阳的邪恶双子星 涅墨西斯 An evil twin to the Sun named Nemesis.
有些科学家怀疑 涅墨西斯是一颗 Some scientists suspect that Nemesis is
不发光且尚未发现的围绕太阳转动的恒星 a dark, still-undiscovered star orbiting our Sun.
而每过两千六百万年 And every 26 million years,
它就会带来一场灾难 it triggers a disaster.
大家都知道 太阳系的周围 We know that the Solar System
环绕着巨大的彗星团 is surrounded by this enormous cloud of comets,
格雷格・洛格林 加利福尼亚大学圣塔克鲁兹分校
因此太阳伴星这一系列运动产生的轨迹 and so these successive passages of the Sun's companion
将会把一些彗星带入太阳系的内部 would send comets into the inner Solar System.
它们有可能撞击地球 Some of them will hit Earth.
而一旦撞击发生 地球将生灵涂炭 What follows is death on a colossal scale.
现在普遍的理论是 在六千五百万年前 It is now widely accepted that a rock from space
一块来自太空的岩石结束了恐龙时代 caused the end of the age of dinosaurs 65 million years ago.
我们现在已有十足的把握认定 So we now are pretty convinced that
六千五百万年前的那场 the reason that a huge fraction of life on the Earth
令地球大部分物种灭绝的灾难 went extinct 65 million years ago
麦克・布朗 加利福尼亚理工学院
是由于一颗彗星撞击地球而造成的 was because a comet slammed into the Earth.
但天文学家理查德・穆勒却提出了 But astronomer Richard Muller has proposed
一套革命性的理论 以解释为何彗星 a revolutionary theory to explain why that space rock
会恰巧在那一时刻撞击地球 crashed to Earth at that particular moment.
涅墨西斯理论描述了这一假想 The Nemesis theory postulates that
即 有一颗恒星在做绕日运动 there's a star orbiting the Sun
理查德・穆勒 美国劳伦斯伯克利国家实验室
而其公转周期为两千六百万年 at a 26-million-year period.
足矣 That's about it.
几乎不需要其它假说来支持此理论了 Almost no other assumptions need to be made.
穆勒认为当涅墨西斯运行到太阳附近时 Muller believes that as Nemesis nears the Sun,
它所带来的引力扰乱 its gravitational disturbance
会使得一些彗星穿越太阳系 sends comets flying through the Solar System.
这种现象的后果就是造成地球历史上 The resulting impacts have been the source of
多次大规模物种灭绝现象的元凶 many major extinction events in Earth's history.
穆勒这样解释他的理论是如何诞生的 Muller explains how the theory came about.
有两位古生物学者 Two paleontologists,
在研究地球生物灭绝的规律时 when looking at patterns of extinctions,
发现了一件似乎十分不可思议的事情 came across something that seemed utterly insane.
他们说 这种类似的灭绝现象 They said that similar extinctions were taking place
大约每两千六百万年就要发生一次 every 26 million years on a regular schedule.
任何地球本身的现象都似乎都无法解释 The discovery of a 26-million-year pattern of extinctions
这个每两千六百万年的物种灭绝规律 seemed impossible to explain by any process native to the Earth itself.
这可是科学家们梦寐以求的事情 This is the sort of thing you dream about in science.
因为这说明有些事物对我们还是未知 It means there's something we don't understand.
说明有未知的事物亟待发现 It means there's a discovery waiting.
于是 我便试图去探求那未解之谜 So I set about trying to figure out what that was.
穆勒提出了一个惊人的假说 Muller made an astonishing proposal.
这些周期性灭绝现象的唯一合理解释就是 The only logical cause of these periodic extinctions
有一颗潜恒星 它每两千六百万年饶太阳一周 is a cosmic stalker that orbits our Sun every 26 million years,
而每一接近太阳就会造成彗星轨道的紊乱 disturbing the comets on each approach.
总之 它是一颗太阳的死亡伴星 In short, a death star companion to our Sun.
如果真的发现这颗恒星 将是意义深远的 If this star is discovered, it is so important.
它在地球上生物进化过程中起到了重要作用 It was a major player in the evolution of life on Earth.
若不是这颗恒星 也许恐龙还在称霸地球 Without this, perhaps the dinosaurs would still be here.
如果穆勒所言属实 If Muller is right,
那么人类之所以能够出现在地球上 humanity itself could owe its existence
还是多亏了这颗名叫涅墨西斯的死星 to the Nemesis death star.
毕竟每次大规模灭绝都清除了大量物种 After all, each mass extinction wiped out vast numbers of species,
但这也为新物种的出现和繁衍开辟了道路 but each also cleared the way for new species to arise,
其中就包括 最后出现的人类 including, ultimately, humans.
通过在加州的圣塔罗莎高原的可控火灾 We can witness the way Nemesis would have altered evolution on Earth
我们便知道涅墨西斯是如何影响地球生物进化的 by looking at a controlled burn on the Santa rosa plateau in California.
灭顶之灾不时降临在地球上 So every now and again, some cataclysmic event happens
克利福德・强森 南加州大学
并将地球上的大量物种一扫而空 that wipes out a huge number of species here on Earth.
就像这些可控火灾一样 And this is just like happens with these controlled burns,
当大火清除了一些物种 where the burn wipes out a number of species,
同时也为新的生命提供了生存的空间 which then makes room for new things to take hold.
我看到火焰在我们身后迅速蔓延 So I'm seeing a fire raging behind us.
你们在做什么 What's going on there?
为什么要放火呢 Why do you light fires?
我们在这里放火 We're out here setting this fire
是为了将这一片植被清理干净 to clear part of this vegetation away,
为了将外来的植物清除 to get rid of the non-native species of plants
好让本地植物得以从新回归 that are growing here so the native can grow back.
每年我们都会来到这里 We come here and burn annually
焚烧不同区域 以便进行分析比较 in different plots of land so that it can be studied,
我们还能够借此了解其对于环境的影响 and we can also see the impact it's having on that environment.
这次计划烧除展示了 A prescribed fire mimics the kinds of
涅墨西斯所能带来的大规模物种灭绝现象 mass extinctions that Nemesis may have caused.
很多物种就此消失 Many species are swept away,
但幸存物种则有空间得以繁衍 不断进化 but the destruction leaves room for the survivors to flourish and evolve...
譬如说 当恐龙突然灭绝后 Just as mammals survived and thrived
哺乳动物幸存下来且日益壮大 after the fiery death of the dinosaurs,
从而为人类的进化奠定了基础 setting the stage for human evolution.
每年在圣塔罗莎都有计划烧除 These prescribed fires return to Santa rosa every year
这种现象仿效了 and imitate the driving motivation
涅墨西斯理论的提出诱因 behind the creation of the Nemesis hypothesis--
即灭绝是不断发生的 that extinctions occur over and over.
对于这些有规律的物种灭绝 There are really only two viable explanations
只有两种合理的解释 for the regularity of the extinctions.
其中一种就是涅墨西斯理论 One of them is the Nemesis theory.
而另一种解释就是机缘巧合 The other is that by the throw of the dice
那些灭顶之灾只不过是 they just accidentally happen to
恰巧每两千六百万年发生一次 line up every 26 million years.
但涅墨西斯究竟是如何做到如此精准地 But how, exactly, would Nemesis trigger extinctions
有规律地造成"计划烧除"呢 with the regularity of a prescribed burn?
在太阳系中一个名为奥尔特云的区域 The possible answer lies in a region of the Solar System
也许能找到我们想要的答案 known as the Oort Cloud.
奥尔特云是大量彗星的"冷藏室" The Oort Cloud is the place where comets are kept in cold storage
直到它们有一天向着太阳呼啸而过 until they come screaming in towards the Sun.
就是说 那些彗星都冷冻在奥尔特云中 So these things are sitting in deep freeze,
它们大概位于为我们与最近恒星的中间 sort of at the distance halfway between us and the nearest stars.
奥尔特云中的大多数彗星 The vast majority of Oort Cloud comets
都在距离太阳远达一光年的安全距离环绕 orbit at the safe distance of up to one light year from the Sun.
除非有什么东西打乱了它们的轨道 That is, unless something disturbs their orbits.
有时 一颗恒星运行到奥尔特云处 Occasionally, a star will come by,
便会稍微推撞一下这些彗星 and they get a little bit jostled.
但是这轻微的推撞却意义重大 And a little jostling can do a lot of things.
它能让彗星完全脱离太阳引力 It can make them go away and leave the Sun entirely.
或轻微改变它们的运行的轨道 It can put them on a slightly different orbit.
还有一个可能 就是使他们慢慢 But one of the things it can do is put them on an orbit that
改变到朝太阳运行的轨道中 slowly falls in toward the Sun.
通过观察杂耍者的动作 By following the motions of a juggler,
天文学家格雷格・劳克林可以直观的看出 astronomer Greg Laughlin can help visualize
为什么类似于涅墨西斯的恒星经过 why cometary orbits are so vulnerable to the effects
会很容易影响彗星轨道 of a passing star like Nemesis.
嗨 格雷格 Hey, Greg.
这是乔希・霍顿 我们需要乔希的帮助 This is Josh Horton, and we've enlisted Josh to
以便于了解楚奥尔特云到底是怎么运作的 kind of help us understand how the Oort Cloud really works.
你一次能让多少球保持在空中 How many balls are you actually able to keep up in the air at one time?
七个 That was seven.
我也能玩八个或者九个 I can do a little bit of eight and nine,
不过一般练习时我都用七个球 but seven is what I practice the most.
杂耍者向空中抛东西时的弧线 The arc of something that a juggler is tossing up is very
和彗星在它的偏心轨道上的轨迹非常相似 much like the arc that a comet makes on its eccentric orbit.
特别是因为球在接近最高点时减速 Especially because it's going slow near the top,
接近最低点的时候加速 and it's going very quickly near the bottom.
如果我们想要模仿整个的奥尔特云 If we want to simulate the whole Oort Cloud,
我们必须同时让多个球运动 then we've gotta keep a lot of balls in motion.
所以我在想你能不能教教我 So I'm wondering if you can maybe give me a quick--
好的 我可以试一下 Yeah. Yeah, I can try.
从两个开始好了 Well, let's start with two.
两个球 Two balls.
你需要做的是 What you're gonna do here
使两个球在空中交叉 is you're gonna cross both balls in the air.
开始扔吧 不对 So it's gonna be throw-- No.
两个球的轨迹要相同 和彗星轨道一样 The throws are exactly the same, just like the path of a comet.
看着 交叉 交叉 So...Cross, cross.
它们在空中划出了一个"X" They're making an "X" In the air.
-它们要同时被扔出去吗 -不对 - Do they leave at the same time or-- - No,
先扔右 再左 接住 接住 It's right, left, catch, catch.
-右 左 -差不多是这样 - Right, left-- - No that was it.
再把你左手那个扔高点就好了 Just throw your left hand a little bit higher.
右 左 接 接 Right, left, catch, catch.
不错 你差不多是同时接住它们的 Good. You're kind of catching 'em at the same time.
右 左 接 接 Right, left, catch, catch.
好一点了 That was better.
我就像是一个太阳系 So I'm a little bit like a Solar System where there's some
有着严重的重力不稳定性 serious gravitational instability in the mix.
乔希同时保持七个球在空中 So Josh is keeping seven balls in the air at the same time,
这和太阳的工作有些相似 太阳是同时保持 and that's not unlike the Sun's job, which is to keep trillions
数万亿的彗星同时运行在奥尔特云的轨道上 of comets all orbiting in the Oort Cloud.
但是根据太阳伴星假说 But according to the Nemesis hypothesis,
每2600万年 太阳的这个微妙的"把戏" the Sun's delicate juggling act is disrupted
就会被它的邪恶双子星干扰一次 by its evil stellar twin every 26 million years.
就像恐怖电影中的鬼怪 这个邪恶双子星 And like something out of a horror movie, this evil twin
是极难察觉到的 could be nearly invisible.
我们的太阳真的有一颗邪恶双子星吗 Does our Sun have an evil twin?
一颗名为涅墨西斯的恒星 A star named "Nemesis"
是否在远离我们太阳系的轨道上运行着 orbiting the distant reaches of our Solar System?
是否每2600万年 它会从奥尔特云向地球 And every 26 million years, does it fling comets
抛掷彗星吗 from the Oort Cloud toward Earth?
有时候它们会被抛出 有时它们也会 Sometimes they get tossed out, other times they orbit
无攻击性的运转直到它们消逝 harmlessly until they evaporate and go away.
如果有彗星群穿越太阳系 If you have comets rattling through the inner Solar System,
格雷格・劳克林 加利福尼亚大学圣塔克鲁兹分校
那么就可以说 一切预测都不准了 then, in a sense, all bets are off.
科学家理查德・穆勒不仅仅提出理论认为 Scientist Richard Muller not only theorizes
这种周期性混乱是受一颗太阳的致命伴星影响 that this periodic mayhem is caused by a deadly companion star to the Sun,
他还确切的了解它是什么恒星 红矮星 he believes he knows precisely what kind of star it is-- A red dwarf.
有一个恒星以2600万年为周期 That there is a star orbiting the Sun
围绕太阳运转 这是我的想法 in a 26-million-year period, that was my idea.
我们假设这颗恒星是红矮星 Let's assume the star is a red dwarf star.
理查德・穆勒 美国劳伦斯伯克利国家实验室
为什么是红矮星呢 Why a red dwarf?
因为这是银河系里最常见的恒星 Because that's the most populist star in the galaxy.
红矮星是一颗很小的恒星 A red dwarf is a tiny star
总重量还不及太阳的十分之一 that weighs in with a mass less than 1/10 of our Sun.
但是正如天文学家格雷格・劳克林所展示的 But as astronomer Greg Laughlin demonstrates,
它的影响就像是在杂耍者抛掷火焰时 it can have the effect of a 9-pod bowling ball
再接住一个八斤重的保龄球 tossed into the arms of a juggler playing with fire.
奥尔特云本身是个很无聊的地方 All by itself, the Oort Cloud is a pretty boring place,
所以我们打算来点刺激的 and so we're gonna have to up the ante a little bit.
这些就代表奥尔特云里的彗星 These are gonna represent the comets in the Oort Cloud.
准备好了吗 Are you ready?
我最好要往后退一点 I think I'm gonna step back a little bit.
乔希让火炬顺利的运动 So Josh has got them all going nicely,
就像是彗星在奥尔特云里运转一样 just like the comets orbiting in the Oort Cloud.
我们来看看如果我把这个红矮星 So let's see what would happen if I took this red dwarf and
扔进太阳系时会发生什么 tossed it into the Solar System.
-乔希 你准备好接红矮星了吗 -好了 - Josh, are you ready for the red dwarf? - Yeah.
开始吧 Here we go.
你可以看见 红矮星闯进太阳系 So as you can see, the red dwarf coming through the solar system
确实改变了彗星群的轨道 has really changed the orbits of the comets.
注意 事实上这两个彗星是落向地球了 Notice that two of these comets actually crashed onto the earth.
这和彗星撞击发生时情况类似 That's not unlike what happens when a giant impact occurs,
大规模物种灭绝就会降临到我们头上 and we get one of these mass extinctions.
地球所经历的一系列冲击 For many people the idea that Earth has been
是由一颗环绕太阳的灾星引发的理论 the victim of a series of impacts caused by
对于大多数人来说都不太可信 an orbiting death star seems unlikely.
毕竟当我们望向天空时 After all, when we look at the sky,
我们只能看见一个太阳 we only see one sun.
但事实上 大部分恒星都是成对出现的 But in fact, the majority of stars come in pairs.
大概有60%或者70%的恒星实际上是 Probably something like 60%, 70% of stars may indeed be
二元的 或者星系中有两颗以上的恒星 binary, or have even higher numbers of stars in the system.
根据理查德・穆勒的太阳伴星假说 According to Richard Muller's Nemesis hypothesis,
我们的太阳是二元恒星系统的一部分 our Sun is part of such a binary star system.
一切都说得通 It all works.
你需要做的就是假设太阳和 All you have to do is hypothesize that the Sun,
银河系里其它三分之二的恒星一样 like 2/3 of all the other stars in the galaxy,
有一个伴星 has a companion--
它2600万年的公转周期 然后就明白了 This one with a 26-million-year period-- And there you have it.
若真为此 But if so,
为什么我们在天上看不见太阳的双子星呢 why don't we see the Sun's twin in the sky?
穆勒说 原因很简单 According to Muller, the reason is simple.
涅墨西斯是一颗极其黯淡的红矮星 Nemesis is an extremely dim red dwarf.
当我第一次提出涅墨西斯这个理论时 When I first came up with the Nemesis theory, the issue was,
问题在于"等等 那为什么没人发现它呢" "Well, wait a minute, how come nobody found it?"
答案很显然 And that was pretty obvious.
它肯定很难被观测到 It has to be hard to find.
据定义 红矮星基本不会发光 By definition, a red dwarf barely glows at all.
它可能是离我们的太阳最近的一颗恒星 It would be the closest star to our Sun,
可是我们居然不知道它的存在 and we wouldn't even know it.
为什么呢 Now, why is that?
我们发现临近恒星的方法无非是因为 The way we discover nearby stars is either because
它们很耀眼 可是红矮星一点也不明亮 they're very bright-- And the red dwarf star is not very bright--
或是因为太阳会经过它 Or because the Sun is moving past it.
这颗恒星和我们一起移动 This star is moving with us.
是的 它围绕我们运转 Yes, it's orbiting us,
但是运转的速度很慢--要2600万年 but that orbit is very slow-- 26-million years.
所以基本上是和地球同步 So it'd be moving with us.
它看上去就像固定在天空中一动不动 It would just be at a fixed position in the sky, and wouldn't move.
换句话说 当从地球上看过去时 In other words, when viewed from Earth,
大部分附近的恒星都在时刻移动中 most nearby objects are shifting over time.
但是涅墨西斯却一直不动 But Nemesis is sitting still.
因此 寻找涅墨西斯逐渐成为热点 So as the search for Nemesis enters high gear,
关键问题在于 何处寻芳踪 one key question is where to look.
所幸科学家们了解双子星的运行方式 Luckily, scientists understand how binary stars orbit each other,
这方法恰可用于寻找涅墨西斯 and they can apply this knowledge to the search for Nemesis.
如果太阳和涅墨西斯质量相当 If both the Sun and Nemesis were of equal mass,
那它们的绕转轨道必是一个巨大的正圆形 they would orbit each other in a vast but equal circle,
寻找涅墨西斯的难度便相对较小 and the search for Nemesis would be relatively easy.
但质量相当的双子星十分罕见 But binary stars are rarely equally sized.
仅有10% 或 20%的双子星 10% or 20% of binary stars have two components
两颗恒星大小完全相当 where the stars are really on an equal footing.
绝大多数情况下 其中的一个 And then there are also a large number of stars where one star
要比另一颗恒星质量更大 is considerably more massive than the other.
若双子星质量大小不等 When binary stars are of different sizes,
较小的一个 即涅墨西斯 the smaller star, in this case Nemesis,
多以椭圆形轨道围绕质量大的恒星 swings in a wide orbit around its larger companion,
也就是太阳 in this case the Sun,
太阳基本上看不出来是在运行 which barely seems to orbit at all.
那么 较小的为何在较远轨道上运行呢 Why does the smaller one move in a much wider circle?
这可以用"质心"的概念来解释 The answer has to do with a concept called the "Center of mass."
我们请一对体操运动员在平衡木上 A pair of gymnasts on a balance beam
为各位做直观的阐释 can help us visualize how it works.
一对双子星绕着它们的质心运行 Stars in a binary pair orbit around their common center of mass.
劳拉・丹利 格里菲斯天文台
如果二星质量相当 If two stars are about the same mass,
它们将围绕中间不可见的点运行 they orbit around an invisible spot in the middle,
该点恰好位于二者正中 right in between the two of them,
就像平衡木上的塔米和卡莉 just like Tami and Carly are balanced on this seesaw.
你们能保持平衡吗 Wow, you guys are balanced?
但与两位运动员不同 But unlike these gymnasts,
涅墨西斯和太阳质量不等 Nemesis and the Sun are not equal.
天文学家理查德・穆勒估算 Astronomer Richard Muller estimates that
太阳的质量是其未知双子星的十倍 the Sun has ten times more mass than its undiscovered twin.
若双子星中的一颗质量大于其"兄弟" And when one binary star is larger than its sibling,
二者的质心将移向较大的一颗 the center of mass between them shifts closer to the larger star.
现在塔米将为我们演示这一理论 So Tami's going to help illustrate that.
塔米 你大概有多重呢 Tami, how much do you weigh?
-大概59公斤 -哦 59公斤 - About 130. - About 130?
在这头 我们放一块约16千克的重物 And we have weights at this end that are about 35 pounds.
这样 你比重物质量的四倍略微轻一点 So you're just a little bit less than four times that weight.
上来 So climb on up.
看看你站在哪 才能维持平衡木的平衡 Let's see where you have to be to balance the balance beam.
鉴于塔米大约是金属重物的四倍重 Since Tami weighs about four times as much as the metal weights,
她必须大幅度移向质心以保持平衡 she must move far closer to the center of mass to maintain balance.
如果塔米和重物代表双子星 If Tami and the weights represented binary stars,
较轻的重物将在较远的轨道上运行 the weights would orbit far out in the distance
而塔米则近于一动不动 while tami would barely move.
事实上 二者是相互围绕运行的 In fact, both would be orbiting each other.
人们常误以为较重的恒星多原地不动 It's kind of a misconception to think that the more massive
而较轻的都以它为中心绕转 star doesn't move, and the less massive star just goes around it.
事实上 它们仍是绕着共同的质心运行 In fact, they're still both orbiting the common center of mass.
较重的恒星 轨道半径较短 The more massive star moves less,
而较轻的恒星 轨道半径较长 and the less massive star moves more.
这一认识对于计算涅墨西斯 This insight is key to calculating where
与太阳的相对距离至关重要 Nemesis might lie in relation to the Sun.
我们知道 公转周期是两千六百万年 We know it's a 26-million-year period.
这提示我们它究竟有多远 That tells us how far out it is.
即其公转半径稍大于一光年 It has a radius of about a little over a light year.
至此我们知道了运行轨道半径 So we know the orbital size.
科学家现已粗略算得搜索范围 Now that scientists know roughly where to look,
寻找涅墨西斯已全面启动 the search for Nemesis is in full swing.
目前 这一研究指向一个令人震惊的理论 And so far, that search has led to an astounding new theory.
不光是太阳有个不为人知的"兄弟" Not only might the Sun have an undiscovered twin,
太阳系里也许藏匿着一颗巨大的未知恒星 the solar system may be harboring a massive undiscovered planet.
太阳邪恶双子星扰动彗星群 In the hunt for an evil twin to our Sun that
将死亡之雨降于大地 我们努力寻其踪迹 shakes comets loose and rains death across the earth,
万事俱备 只欠东风 all of the pieces are in place except one.
要使涅墨西斯理论成立 The Nemesis theory really needs the smoking gun of
克利福德・强森 南加利福尼亚大学
必须有确凿证据 actually finding direct evidence for the object itself
证明涅墨西斯确实存在 in order for the whole thing to hold together.
那么 为何我们现在还毫无所获 Now, why haven't we found it yet?
事实上 有不少天文学家对此漠不关心 Actually, there are quite a few astronomers who don't pay very
理查德・穆勒 美国劳伦斯伯克利国家实验室
他们简单的认为 much attention to this, and simply assume that
如果该星存在 那么应当早就被人们发现 if it existed, it would have been found by now.
我们坚信 在接下来的几年该星会被发现 We believe this thing can be found within the next few years.
我们要做的 是对暗星进行一次认真研究 What it takes is a survey of dim stars.
启用"智者" Enter WISE,
即沿轨道运行的大范围红外研究探测器 the orbiting "Wide-field infrared survey explorer,"
可能成为揭开涅墨西斯之谜的强大新仪器 a powerful new tool that just might crack the Nemesis mystery.
"智者"之所以如此出色 The reason that WISE is gonna be so good
麦克・布朗 加利福尼亚理工学院
正是因为它采用红外技术 is because it operates in the infrared.
简单地说 它可以观察到热源 It sees heat, basically.
红外扫描仪通过测算热源 而非传统光源 By measuring heat instead of light, infrared scanners
可以轻易发现发热但不发光的物体 can make warm but dark objects easy to spot.
通过红外观察热源的优势在于 The nice thing about looking in the infrared at the heat of
恒星与太阳的距离对观测没有影响 it is you don't care how far away you are from the Sun.
我们以木星为例 Jupiter provides an example.
木星表面的温度 The temperature on the surface of Jupiter
约为摄氏零下145度 measures 230 degrees below zero fahrenheit.
但较之摄氏零下270度的宇宙空间温度 But that's blazing hot when contrasted with
这又是如火般炙热的 the 450-degree-below-zero temperature of space.
所以 即便缺少太阳的照耀 So even in the absence of sunlight,
类似木星这样较远的恒星 a distant, Jupiter-like planet
也可能在红外扫描中 发出耀眼的光芒 would glow brightly in the infrared.
我们可以在赛车跑道上直观地了解 By visiting a motor speedway, we can see how the WISE
"智者"红外技术比对不同温度的物体 survey might help find Nemesis by exploiting the infrared
对寻找涅墨西斯究竟有何益处 contrast between objects of different temperatures.
在这 轰鸣的发动机只能展示过程的一半 Here, the roar of the engine only tells half the story.
今天 我们来到驾驶技术竞速学校 I came out here today to the drive tech racing school
亚历克・弗里喷库 加州大学伯克利分校
坐进一辆赛车 to be in a race car
在跑道上跑几圈 that would go zooming around this track a bunch of times.
我们要用红外相机拍摄赛车 An idea was to film the car with an infrared camera,
以显示出高热的物体 and show us things that are hot--
温度高于周围环境 hotter than the outside surroundings--
在红外光谱中发光的物体 and glowing at infrared wavelengths.
-泰德你好啊 -你好 - So, hey Ted! - How you doing?
幸会幸会 Good to meet you.
彼此彼此 Likewise.
今天是你来开车吗 Yeah. You're the driver?
是的先生 Yes, sir.
我们打算开多快呢 Now, how fast are we gonna be going?
大概每小时274公里吧 Approximately 170 miles an hour.
差不多就是普通高速路行驶速度的三倍 Now, that's about three times normal highway driving speed, so
看来等下真的会"热火朝天" whoa, things are really gonna heat up.
是啊 Oh, yeah.
闲话少说 出发吧 All right, let's go, then.
工作人员布莱尔・迪普利帮我钻进这辆车 Blair Dupree of drive tech helped me get into the car.
带好护具 这个厚重的头盔 Good protection. This is a nice, thick helmet.
车门都没有 这可不太容易 And it's not so easy, because there's no doors, okay.
你得从窗户爬进去 You have to kind of climb in through a window.
把左脚抬起来放进去 Bring your left foot up in there. Okay.
再把右腿放进去 Bring your right foot on up.
我感觉自己像是"破车而入" I feel like I'm breaking into a car.
然后再钻进去 And then kind of slither your way in.
在赛车里的感觉真棒 Being in that race car was really exciting.
当我们转弯时 When I was going around the turns,
我能感到强烈的离心力 I could really feel the g-forces.
泰德开得不错 是吧 Ted give you a good ride, did he?
幸亏是泰德开车 Yeah, well, I'm glad Ted was the driver.
我真的来不了这个 我去 I couldn't do this, you know?
我吓得腿都软了 而且我还是坐车的 I was scared out of my seat, and I wasn't even the driver, okay?
车辆预热完毕 热成像专家 With the car nicely warmed, a FLIR infrared camera,
罗斯・欧文斯利特架起一台红外摄像机 set up by thermal-imaging expert Ross Overstreet,
以全新的方式观察一切事物 sees everything, literally, in a new light.
你好 亚历克 Hello, Alex.
罗斯 还好吗 Hey, Ross, how you doing?
-很好 情况怎么样 -好 很好 - Doing good. How you doing? - Good, good.
让我们看看这些红外图像 Let's look at these infrared images.
我们正在拍摄车的尾部 Right now we're pointed at the back of the car.
这台仪器的好处是 The best way to think about it is
与其说是摄像机它更像是测量仪 it's more of a measurement device than a camera.
这张图上好像有无数温度计 It's like having a million different thermometers spread across the image.
每一个像素都能体现出测量温度 We're actually getting temperature measurements on each of those pixels.
温度高的地方 Things that are supposed to be hot
就呈现出红色 橘黄色和白色 look like they're glowing red and orange and white.
温度低的地方则是蓝色和黑色 Things that are cold are colored blue and black.
也就是我们熟知的冷色调 You know, colors you associate with cool objects.
-对 -你可以看到 - Right. - And you'll notice there's
这辆车上有几个不同的热区 several different hot areas of the vehicle.
我看到轮胎上的温度不太一样 Now, I see some variations across the tires.
你可以看到 Yeah, and you'll notice that
一个轮胎比另外一个轮胎稍许热些 the one tire is a little bit warmer than the other.
右胎温度果然高于左胎 The right-hand tire was indeed hotter than the left-hand tire
因为在转弯时右胎受压更大 because there was more pressure on it during the turns.
那么右胎能达到多少度呢 So how hot is that hotter tire there?
我们先前测量过 大概有摄氏89度 We made a measurement earlier of about 190 degrees fahrenheit.
这跟开水的温度差不多了 Almost the temperature of boiling water on the tires.
仅用肉眼 我们不可能区分出 When we just look by eye, we can't tell whether something is
哪里温度更高 hotter than something else.
但这样你就可以区分了 真不错 But here you can tell, and that's really cool.
是的 这台摄像机在漆黑的夜里 Right. And this camera would work just as well
和在大白天都能工作 if it was pitch black or in the middle of the day.
阳光对它没有影响 It doesn't care about solar light at all.
红外摄像机拍摄赛道的原理 The infrared camera sees the racetrack
和用"智者"探测 the way the WISE survey
黑暗而又遥远的太阳系领域的原理一样 scans the dark and far-away realms of our Solar System.
如果涅墨西斯真的存在 If Nemesis is out there,
那么红外线应该能探测到 infrared should reveal it.
赛车上的热点就像是那些远离太阳 The hot spots on the race car are sort of like warm,
在寒冷的太空中熠熠发光的温暖恒星 glowing objects out in the cold depths of space, far from the Sun.
这是一种探测遥远恒星的全新技术 This is a whole new way of discovering objects--
这些恒星利用光学望远镜是捕捉不到的 Objects too faint to be seen through a normal optical telescope,
但红外线却能探测到 but bright enough to be detected in the infrared.
"智者"于2011年初完成了探测任务 The WISE telescope completed its sky survey in early 2011,
但对涅墨西斯的探测还没定论 but in the search for Nemesis, the results are still inconclusive.
"智者"探测结果要花很长时间去分析 The WISE survey is going to take a long time to analyze,
因为它收集到了 simply because there's a huge amount of data
海量的数据 that had been gathered by this craft.
我们仅研究了半数可能是涅墨西斯的天体 About half of the Nemesis candidates have not yet been studied.
我们预计 这个理论是对是错 But in the next few years, we expect the theory
将在接下来的几年里被证实 will be either proven right or wrong.
在那之前 有争议纯属正常 Until that time, it is and should be controversial.
为何距地球这么近的恒星如此难以发现 That something so relatively near to Earth can be so obscure
来自阿州莫比尔的弗兰克・切科夫斯基 is what Frank Jankowski of Mobile, Alabama,
想要询问宇宙 wants to ask The Universe.
为什么科学家们能观察到百万光年以外的天体
却不能找出在我们太阳系边上的天体
弗兰克 这是个有趣的问题 That's an interesting question, Frank.
百万光年以外的天体能被天文学家发现 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.
它们能产生大量能量 They produce a lot of energy on their own,
就像是正在爆炸的恒星 like an exploding star.
但是在我们太阳系边上的天体可能很小 But an object near the edge of our Solar System might be small,
只反射微乎其微的太阳光 and it reflects only a little bit of sunlight,
所以我们在可见光的波段看不到它 so we can't see it at visible wavelengths.
询问宇宙
科学家在分析涅墨西斯的探测数据时 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 Although calculations indicate that
涅墨西斯要几百万年以后才会回来 Nemesis isn't due back for millions of years,
有颗恒星正在扰乱奥尔特云中的彗星 something appears to be shaking up the comets in the oort cloud right now.
难道涅墨西斯已经兵临城下了吗 Could Nemesis already be upon us?
自从涅墨西斯理论被提出 Since the birth of the Nemesis hypothesis,
天文学家们就密切注意着 astronomers have been on the lookout
会周期性扰乱奥尔特云中彗星引力的 for a faint red star that periodically disturbs the gravitation
黯淡的红矮星 of the Oort Cloud comets.
每隔2600万年 这会使得它们 This sends them on a catastrophic rendezvous
穿越包括地球的内太阳系 with the inner Solar System,
发生灾难性的碰撞 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,
他们发现了令人不安的迹象 they have uncovered unsettling evidence
有东西正在干扰彗星的运行轨道 that something is disturbing comet orbits right now.
涅墨西斯已经回来了吗 Has Nemesis already returned?
如果太阳独立存在 没有涅墨西斯 If the Sun was all by itself, and there was no Nemesis,
那么奥尔特云中的彗星 then the comets in the Oort Cloud
它们的运行轨道将是可预测和规律的 would all have very predictable and regular orbits.
格雷格・洛格林 加利福尼亚大学圣塔克鲁兹分校
它们到达和出发的时间应该很有规律 They'd be very regular in their arrival times and departure times.
如果只有太阳的引力干扰 Without gravitational interference from anything other than the Sun,
奥尔特云中的彗星就如杂耍物体 Oort Cloud comets, like juggled objects,
在宇宙中有规律得运动 could spread out evenly across the sky.
但这并不是一些科学家们得出的结论 However, that's not what some scientists report.
我们仰望星空 观察这些彗星从何而来 When we look out into the sky, and look at where the comets are coming from,
它们的方向往往集中在天空的某个固定区域 their directions tend to concentrate in a certain region of the sky.
有一个可能的解释是 And one possible explanation for that is that
这种偏移是一个我们看不见的天体 that skew is being directed by the gravitational perturbations
发出的引力干扰所导致的 from an unseen object that is out there.
基于这些研究 科学家们推测 Based on these observations, scientists infer
有一个巨大的天体正在干扰奥尔特云 that a huge object is disturbing the Oort Cloud.
这个道理和加利福尼亚运输官员 They do this the same way that California transit officials
推测扰乱洛城交通秩序的事故如出一辙 infer that an accident is disturbing traffic patterns in Los Angeles.
马克 我们在哪 So, Marco, where are we?
这房间是做什么的 What is this room?
墙上的图 Well, the map we have here on the wall,
是高速公路系统图 that's our freeway system map.
如你所见 And as you can see,
它显示了洛杉矶主要的高速路线 it shows the major freeway routes in Los Angeles.
绿点表示正常的交通车流 The green dots represent normal traffic flow,
红点表示 while the red dots indicate
某些原因引起了交通阻塞 that something is causing traffic to back up.
速度只是发生事故的一个迹象 So the speed here's just one indicator that something's going on,
但想知道到底发生了什么 but to really know what's going on,
你必须得有一个摄像头 you either have to have a camera
或是在现场的人告诉你到底发生了什么 or a report from somebody who's actually there and able to tell you what it is.
非常正确 That's correct.
天文学家总是遇到这样的问题 Astronomers have this problem all the time,
他们试图研究他们并不能真正看到的东西 they're trying to understand what they can't actually see.
劳拉・丹利 格里菲斯天文台
天文学中 我们经常指出 In astronomy, we frequently infer
某物体的存在 并非因为我们亲眼所见 the existence of something, not because we can actually see it,
而是因为我们能够看到 but because we can see the influence
它对周围事物的影响 it has on the objects around it.
无论是车流太多还是高峰时段的车道太少 Whether too many cars or crowding too few lanes during rush hour,
或者是事故阻碍了交通 or an accident is slowing traffic flow,
一定有什么造成了拥堵 something causes congestion.
既然科学家们在奥尔特云中观测到类似现象 Since scientists see similar congestion in the Oort Cloud,
涅墨西斯有可能是罪魁祸首吗 could Nemesis be the perpetrator?
这地方真棒 This place is very impressive.
能得到所有监控录像和探测数据 It's got all the cameras, all the sensor data,
还有所有加州高速路巡逻事件的报告 all the California highway patrol incident reports.
这比天文学家研究的数据多得多 This is far more data than astronomers have to work with.
如果我们在太阳系周边布有无数摄像机 If we only had remote cameras all throughout the outskirts of the Solar System,
我们会更好的了解它 we might know a lot more about it.
尽管没有远程相机 Even without remote cameras,
科学家们提出了一个非凡的理论 scientists have proposed a remarkable theory
以解释奥尔特云中的堵塞 to explain the congestion in the Oort Cloud.
根据该理论 According to this theory,
干扰奥尔特云的原因不是涅墨西斯 the culprit disturbing the Oort Cloud isn't Nemesis.
而是同样让人惊讶的 Instead, it's something equally
一颗巨大且未知的恒星 astounding-- A giant, undiscovered planet,
质量是木星的四倍 four times the mass of Jupiter.
简言之 它是太阳系最大的恒星 In short, the largest planet in the Solar System.
科学家称它为堤喀[命运女神] Scientists have proposed naming it Tyche.
简单的说 堤喀是"小版的涅墨西斯" In a nutshell, Tyche is "Nemesis light."
涅墨西斯 在最初的假设中 Nemesis, in the original hypothesis,
是一颗红矮星 was literally a red dwarf star.
质量是木星的100倍 Something that was 100 times more massive than Jupiter.
不像涅墨西斯 堤喀不会像星星一样发光 Unlike Nemesis, Tyche would not glow like a star.
它更像是变形版的木星 Instead, it would look like a strange version of Jupiter.
如果你戴上夜视镜 If you put on night-vision goggles,
会看到很不一般的景象 then it would be quite a bit more impressive sight.
你能看到云中的裂缝和闪电 You would see breaks in the clouds, and there would be lightning.
你会看见云层被它底下的闪电 You would see the clouds light up from the lightning down
照亮 beneath the cloud tops.
堤喀可能会影响奥尔特云中彗星的轨道 Tyche might disturb the orbit of comets in the Oort Cloud,
但它绝不是地球周期性物种灭绝的原因 but it can't be the source of Earth's periodic extinctions.
首先 它的假定位置 First, its proposed position
决定了其100万年的公转周期 puts it on a 1-million-year orbit,
而非像涅墨西斯一样的2600万年 not 26 million, like Nemesis.
其次 它太小了 Second, it's too small.
堤喀没有引力来移动彗星群 Tyche doesn't really have the gravitational mojo to dislodge comets,
造成这些周期性的毁灭 send them crashing in these periodic extinctions--
真的重组奥尔特云 really rearrange the Oort Cloud.
所以它的影响仅仅是一些小的偏移 And so it's effects would be visible only in these small skews,
而不会引发大量彗星突然来袭 and not in the form of huge pulses of comets coming out of seemingly nowhere.
如同涅墨西斯一样 NASA的"智者"探测 Just as with Nemesis, NASA's WISE survey
应该能探测到堤喀 只要它存在 should be able to detect Tyche, if it exists.
当我们惊讶于太阳系可能藏有一颗 While it's surprising that our Solar System might harbor a
巨大且未知的恒星 该理论既没有支持 giant, undiscovered planet, it doesn't support or refute the
也没有驳斥未知的涅墨西斯的存在 idea that it also harbors the undiscovered star Nemesis.
但近期一个对外太阳系的发现 But a recent finding in the outer Solar System
可能有助于探索涅墨西斯是否存在 may shed more light on whether Nemesis really exists,
和了解它对地球生命的威胁 and the kind of threat it may pose to life on Earth.
2003年 天文学家麦克・布朗 In 2003, astronomer Mike Brown
有了一个历史性的重大发现 made a historic discovery
他在夜空中发现了一颗令人无法解释的恒星 when he found something floating around the night sky he couldn't explain.
我记得我发现塞得娜的那天 I remember the day that I discovered Sedna.
看着我电脑的屏幕和那些图片 Looking at it on my computer screen, looking at these pictures,
麦克・布朗 加利福尼亚理工学院
我的第一反应是"这不是真的" my first reaction was "That can't be real."
那太遥远了 It's too far away.
不会有这样的东西存在于太阳系中 Nothing like that exists in the Solar System.
他无意中发现的 What he stumbled upon
恰好是一颗比月球要小的小恒星 turned out to be a planetoid just smaller than our moon,
现在被命名为塞得娜 now named Sedna.
然而塞得娜引出了一个科学难题 But Sedna presents a scientific quandary.
塞得娜离太阳最近距离 At its nearest point, Sedna lies about three times farther away
是木星和太阳距离的三倍 在此区域中 from the Sun than Pluto, in a region where astronomers never
天文学家从没想过会发现恒星 expected to find planetary bodies.
这是我们知道的 It's the coldest, most distant place
整个太阳系中最寒冷和遥远的地方 that we know in the whole Solar System.
如果你坐在塞得娜的表面 If you were sitting on the surface of Sedna,
你可以拿一根大头针 然后伸直手臂 you could take a straight pin and hold it out at arm's length,
仅用大头针的顶端 你就能覆盖住太阳 and with the head of that pin, you could cover up the Sun.
除了处在出人意料的边远区域 In addition to being in an unexpectedly distant region,
塞得娜还在太阳系中有着广阔的椭圆形轨道 Sedna also takes a wildly elliptical orbit through the Solar System.
奥秘就在于塞得娜附近没有任何事物 The mystery is there's nothing anywhere near Sedna that could
可以产生如此遥远和极端的轨道 account for an orbit that distant and that extreme.
它现在所处的位置 不受任何物体影响 The place where it is now, nothing ever affects it.
它周围没有任何星球 It doesn't come close to any planets,
没有恒星接近过它 there are no stars that ever come close to it.
那是什么迫使塞得娜形成如此独特的轨道 So what forced Sedna into its unique orbit?
理论上 死星涅墨西斯是否对其有影响呢 And in theory, could the death star Nemesis have played a role?
对于布朗来说 蹦床帮助解释了 For Brown, the bounce of a trampoline offers a way to
塞得娜是如何形成让科学家 understand how Sedna ended up in an orbit
匪夷所思的独特轨道 that remains a head-scratcher for astronomers.
以60里面为单位 我身后的测量杆 I have behind me a measuring stick that gives how high I'm
能测出我将要跳多高 gonna bounce in 2-foot intervals you see here.
弹跳高度代表 在我的运行轨道上 And what that bounce is supposed to represent is how far away
我离太阳有多远 from the Sun I am in my orbit.
在普通的恒星轨道上 圆形的恒星轨道 In a normal planetary orbit, in a circular planetary orbit, the
恒星围绕着太阳运动 planet circles around the Sun,
和太阳总是保持不变的距离 always staying the same distance from the Sun.
就有点像我站在蹦床上 And that's sort of like me staying on a trampoline, always
和地面总是保持着相等距离 the same distance from the floor.
除了沿着圆形轨道运动 Other sorts of orbits can be,
其它的公转轨道 instead of going in a circular orbit,
可以环绕着太阳 沿着椭圆轨道运动 you can go in an elliptical orbit around the Sun.
你远离太阳 又朝着太阳转回来 You move away from the Sun, you come back towards the Sun.
所以你会越来越远然后越来越近 And so you'll be moving further away and getting closer.
就和你在蹦床上开始上下跳动一样 And that would be starting to jump up and down on the trampoline.
如同地心引力维持公转 Like gravity keeping us in orbit,
当我们到达弹跳顶点 when we reach the apex on the trampoline,
重力会把我们拉下来 gravity will pull us back down.
所以只要没有什么干扰我 我就会一直 So as long as nothing happens to me, I stay in this orbit
在这条轨道上 上下跳动 forever, jumping up and down,
总是达到同一高度 always to the same height.
但一些不平常的因素影响着塞得娜 But something unusual afflicted Sedna.
它碰到了一种神秘力量 It brushed up against a mysterious force
将它推入了一个没有恒星存在的区域 that shoved it into a region where no planetary body should exist.
有人怀疑这种力量就是涅墨西斯 Some suspect that force was Nemesis.
假如太阳的邪恶双子星存在 And if the Sun's evil twin is out there,
科学家们便可以预测 scientists can tell exactly
我们何时看到其回归的可怕迹象 when we'll see the terrifying signs of its return.
就在天文学家寻找一颗名为涅墨西斯时 As astronomers search for a death star named Nemesis
它可能会周期性对地球造成大量物种灭绝 that might periodically cause mass extinctions on Earth,
近期对于小世界塞得娜的发现 the recent discovery of a tiny world named Sedna
也许提供了线索 could prove key.
亿万年前 塞得娜围绕着太阳公转 Billions of years ago, Sedna revolved around our Sun,
就像其他星球一样 其轨道近乎圆形 like other planets, in a nearly circular orbit.
然而有两件不同寻常的事情发生了 But then two strange things happened.
首先 塞得娜被某物推入一个椭圆轨道 First, something forced Sedna into an extremely elliptical orbit.
然后另有其物把轨道推到如此远的地方 And then something else pushed that orbit out so far that it
以至科学家们无法给出合理的解释 seems to defy any visible explanation.
首先 它的椭圆形轨道是如何形成的 The first question-- What caused it's elliptical orbit--
已被轻易阐解 is fairly easily explained.
它可能仅是由于来自外部的巨型气体恒星 It could simply have been gravitational tugs from the
木星和土星所产生的引力牵引 outer gas giants Jupiter and Saturn.
我们可以用蹦床来说明 A trampoline can help illustrate.
为了真正了解太阳系内恒星轨道的运行方式 To really understand how orbits in the Solar System work
以及我们找到的这些极椭圆的轨道 and we get these very elliptical orbits,
我们要尽量在蹦床上跳高点 we need to get more height on the trampoline.
麦克・布朗 加利福尼亚理工学院
我可做不到 所以 肯 你来帮我跳 And I can't do it, so, Ken, I'm gonna need your help.
-好极了 我准备好了 -我先站开点 - Well, awesome, I' ready to help. - Let me get out of your way.
正如蹦床上多一个人的帮助就会使弹跳更高 Just as extra people on a trampoline create extra bounce,
太阳系中巨型气态恒星间产生的重力弹力 the large gas giants in the Solar System can create enough
足以使小恒星的轨道伸展成宽阔的椭圆型 gravitational bounce to stretch a smaller body's orbit into a wide ellipse.
这代表塞得娜在椭圆轨道上运行 So here's Sedna on a nice elliptical orbit.
紧接着塞得娜向其中一颗恒星靠近了一点 But then Sedna got a little bit close to one of the planets.
与此同时 这颗恒星所提供的额外引力 As soon as it does that, the extra gravity of the planet
促使了椭圆轨道的一点点变大 gives it a little boost into an even more elliptical orbit.
之后它靠近另外一颗恒星 也就是木星 But then it gets close to another planet-- Let's say Jupiter.
这是木星 Here comes Jupiter.
它弹跳得更高了 It bounces even higher.
借助木星足够强的弹力 With enough bouncing from Jupiter,
我们可以使塞得娜弹出太阳系 we could bounce Sedna all of the way out of the Solar System.
由木星和土星证明了的轨道弹力 The orbital bounce provided by Jupiter and Saturn
能帮助解释塞得娜的轨道为何呈椭圆状 can explain how Sedna's orbit got its elliptical shape,
但其不能解释它为何最终被推入太阳系的边缘 but not how it ended up being forced into a distant region of the solar System,
在那里 科学家们认为不会恒星存在 where scientists never expected to find a planetary body.
塞得娜原本是在一个椭圆轨道上 Sedna was on an elliptical orbit,
现在它运行得逐渐越来越远 getting further and further and further.
它在远端轨道的时候 发生了什么 And then something happened to it when it was out here.
另一种引力将其强行推入另一个轨道 Some other gravitational force pushed it off into a different orbit,
导致它不会回到它之前的公转轨道 and so it didn't come back to the same place it was before.
就好像有某种擦身而过的次要引力场 It's as if some second gravitational force was passing by
把塞得娜强行推进一个不同的蹦床上 and shoved Sedna onto a different trampoline,
因此它被弹入了一个意想不到的地方 so that it bounces in an unexpected region.
最有可能的情况是太阳附近有另一颗恒星 The most likely answer is that there was another star very close to the Sun
这段时间塞得娜正在经历这个过程 at the time when Sedna was going through this process.
太阳系可能是从一丛恒星群中诞生而成的 The Solar System probably formed in a cluster of stars,
格雷格・洛格林 加州大学圣塔克鲁兹分校
所以它与邻近的恒星甚至是流浪恒星的交汇 and so close encounters with nearby stars, nearby rogue planets even,
这样的事情 were much more common
在太阳系形成的最初期是很寻常的事情 during the very earliest days of the Solar System's formation.
太阳的这些兄弟姐妹们大多早已无影无踪 Most of these solar brothers and sisters have long since dispersed.
但根据涅墨西斯假说 But according to the Nemesis hypothesis,
有一颗仍逗留于此 它仍然环绕着太阳 one of them is still out there, still circling the Sun,
仍旧周期性的引发彗星冲撞 still causing periodic chaos amongst the comets,
仍然在等待再次将灭顶之灾降于地球 and still waiting to rain death on the Earth once more.
如果假设成立 If that is correct,
我们的后代在涅墨西斯归来之时 future generations will be faced with a monumental threat
将面临一场生死浩劫 when Nemesis returns.
时间约为一千万年 In 10 million years.
月亮 火星这些行星 The Moon, Mars, the planets would basically
它们在以后还是会保持原状 be unaltered from their current condition.
在地球上 城市可能不复存在了 On Earth, cities might not be there,
但是对于陆地来说 but the continents would still be
极有可能与它们现在所处的位置不差分毫 almost in exactly the same places that they are now.
但是 根据涅墨西斯假说 But according to the Nemesis hypothesis,
距太阳一光之遥 一场巨变正在进行中 a major change is underway one light year from the Sun.
一颗暗红的恒星已经进入了奥尔特云 A dark-reddish star has entered the Oort Cloud.
涅墨西斯归来了 Nemesis has returned.
如果人类仍在地球上生存 If humans still exist on Earth,
他们即将面临一个缓缓酝酿的宇宙威胁 they'll face a slow-building but imminent cosmic threat.
亚历克・弗里喷库 加州大学伯克利分校
奥尔特云团可能有十亿余颗彗星 The Oort Cloud contains perhaps 10 trillion comets, maybe even more.
但是 它相当庞大 But remember, it's really big.
所以若你置身奥尔特云团之中 So if you were in the Oort Cloud,
它不会让你时刻都被彗星撞击 it's not like you would be pelted by comets all the time.
它们之间的间距一般都很大 The spaces between them would pretty big.
就像这颗杂耍人手中的保龄球 Like a bowling ball in a juggler's hands,
涅墨西斯只会让少数彗星轨道混乱 Nemesis simply shuffles some comets out of its way.
理查德・穆勒 美国劳伦斯伯克力国家实验室
奥尔特云团的中间有一块空旷的地方 The Oort Cloud has an empty region in the middle.
它是被木星和太阳清理干净的 It's been cleaned out by Jupiter and by the Sun.
我们就生活在这里 We live in that region.
但随着涅墨西斯的靠近 But as Nemesis approaches,
太阳系的内部就成了一个射击场 the inner Solar System becomes a shooting gallery.
因此有可能会出现数量比平时稍多的彗星 And so there would start to be a few more comets than usual,
然后突然 满眼望去 尽皆彗星 and then, suddenly, there are just comets, comets coming all the time.
数量最多的时 每年将有一千至一万颗彗星 And at the peak, there might be 1,000 to 10,000 comets per year in the sky.
分析显示 According to the projections
地球会成为会成万箭彗星的靶心 Earth would be in the crosshairs of this comet storm
长达一百万年之久 for a million years.
在这一百万年中 Over a period of a million years,
可能有约十亿颗彗星造访 there would be visits by about a billion comets.
事实上 你可以算一算 Actually, you do the calculation,
总归有一颗会撞上地球 或者两颗 it turns out one of them will hit the Earth. One or two.
很难准确预言 It'd be difficult to predict exactly
它究竟会在何时发生 when the impact would happen,
不过可能会有这么个阶段 but there would be this phase--
是一段危险的时间 This sort of danger zone in which the chances
在此期间 彗星撞击地球的几率 for a catastrophic impact with something of a comet's size
要比现在高很多 would be much, much higher than they are now.
这次冲撞会再次引发地球物种覆灭吗 Will the impact spark another catastrophic extinction on Earth?
有可能 Perhaps.
除非人类坐以待毙 But only if we let it happen.
我喜欢开玩笑说涅墨西斯这次失算了 I like to joke that Nemesis planned this one poorly.
我们处于上次大灭绝与下次之间 In between the last extinction and the next one,
高智能的生物有大把的时间集中精力 there's plenty of time for intelligent life to get its act together
确保涅墨西斯再次归来时 to make sure that next time Nemesis comes back
虽天空彗星满布 and the sky is filled with comets,
却都不会撞击地球 to make sure that none of them hit us.
覆灭之路是无法避免的吗 Is this future inevitable?
除非科学家们找到涅墨西斯 Until scientists either discover Nemesis
或完全否认其存在 or definitively rule it out,
没人能够确定 no one can know for sure.
要知道这不仅仅只是一次抽象的假设 It's important to realize this is not just an abstract discussion.
克利福德・强森 南加利福尼亚大学
这些物体撞击地球无疑是小几率事件 Clearly, these objects colliding with Earth happen very rarely.
但换个角度来说 当它们真的撞上来了 But on the other hand, when they do collide,
它们带来的冲击是巨大的 they're extremely cataclysmic.
所以我们能做的 So what we need to be able to do
是要更进一步的了解太阳系 is get better understanding of our Solar System,
并密切留意我们的天空 and keep an eye on the sky,
因为它可能会是决定我们生死的关键 because it maybe crucial for our survival.
如果未来有一天 真的彗星漫天 If the future sky one day does fill with comets,
人类也许会找到一条自救之路 perhaps humanity will have found a way to save itself
而非最终成为太阳邪恶双子星的又一牺牲品 rather than end up one more victim of the Sun's evil twin.