3
嗨我是John Green
Hi, I'm John Green,
这里是速成课：大历史
this is Crash Course Big History.
今天我们将谈一谈太阳系的形成
Today we're gonna be talking about
今天我们将谈一谈太阳系的形成
the formation of the solar system,
大约在45.67亿年前
approximately 4.567 billion years ago.
4 5 6 7
这只是个巧合吗？
Could that possibly be a coincidence?
是的
Yes.
所以如果你读小学的时候并不是每一分钟都在打瞌睡
So if you weren't asleep during like, every minute of grade school, 你应该会比较熟悉太阳系的基本布局
you're probably familiar with the basic layout of the solar system 以及太阳系的8大行星以前是9大
and the eight, formerly nine, planets.
你可能不知道的是
What you may not know is
13
为什么行星会与恒星和生命一起
how the planets fit between the stars, and life
成为宇宙“越来越复杂”主题的关键
as the linchpin of rising complexity.
老师！老师！
Mr. Green, Mr. Green!
冥王星怎么了？
What about Pluto?
噢过去的我
Oh, me from the past!
我知道人们都同情失败者
I know people like to root for the underdog,
尤其是这个失败者还和米老鼠的宠物狗同名
particularly when the underdog shares
尤其是这个失败者还和米老鼠的宠物狗同名
a name with Mickey Mouse's dog.
跑题了
Off topic,
但为什么米老鼠会有一只宠物是狗
but how come Mickey Mouse has a dog who is a dog,
同时自己还有一个朋友高飞也是狗？
and also a friend, Goofy, who is a dog?
不过请记住 Pluto同时还是罗马冥界之神的名字
But just remember that Pluto also shares a name
不过请记住 Pluto同时还是罗马冥界之神的名字
with the Roman god of the underworld,
这个神非常不招人喜欢
who was very unlikable.
但不管怎样
But regardless,
“行星”这个词
the word "planet"
是人们为了描述某种自然现象而人为创造的一种分类
is a man-made classification for a natural phenomenon.
我们这么做是为了更方便做科学研究
We use it because it makes it easier to do science.
冥王星无法像通常的行星那样
Pluto hasn't cleared the rocks
把进入自己轨道的宇宙碎块清理干净
within its neighborhood orbit, like planets usually do,
而太阳系的边缘又存在着矮行星
and there's even a dwarf planet on the edge of our solar system
阋神星
Eris,
比冥王星的体积还大
that's bigger than Pluto,
还有其他数百个矮行星在各方面都不比冥王星差
and there are hundreds of others that are comparable to Pluto.
宇宙的本质并没有变
The nature of the universe has not changed,
只是我们发现冥王星的表现并不像一颗行星
it's just that we learned that Pluto was not acting like a planet, 所以我们能不能不要再纠结冥王星了？！
so can we please just drop the Pluto thing?!
所以我们现在要从跨度长达几百万光年的星系
So we're now moving from the scale of galaxies,
所以我们现在要从跨度长达几百万光年的星系
which involve millions of light years,
来到距离太阳只有几小时光程的我们的邻居
to a neighborhood that's only a few light hours from the sun,
来到最遥远的行星海王星
to Neptune the farthest planet
最远我们甚至会到达
or at most, a light year or two
距离我们1~2光年布满数十亿彗星
to the distant Oort cloud of billions of comets
仍然受到太阳引力约束的奥尔特云
held by the gravity of our sun.
所以上一集我们谈到
So last episode we talked about
星星就像是我们的曾曾曾曾曾曾祖父
how the stars are like our great-great-great
星星就像是我们的曾曾曾曾曾曾祖父
many-many-times-over grandparents.
其实星星实际上也是太阳的父亲
Well, our sun actually had stars as its parents, too.
太阳很可能是第二代星星
It's most likely a second generation star,
这意味着太阳是由先前死去星星的残骸形成的
which means that the sun was formed
这意味着太阳是由先前死去星星的残骸形成的
from the wreckage of previous dead stars,
并且太阳所包含的元素并不只有氢和氦
and that it contains elements other than just hydrogen and helium 还有在星星肚子里形成的更重的元素
heavier elements that are forged in the bellies of stars
以及一些通过超新星爆发抛撒在宇宙中的重元素
and some of which are, like, flung out by supernovae.
当太阳刚变成恒星时
When our star formed,
它巨大的引力
its immense gravitational pull
将太阳系中99.99%的物质都吸入了自身内部
sucked in 99.99% of all the matter in the solar system,
所以这么说来我们都是剩下的那0.01%
so in this case we are all the 0.01%.
不过本质上
But essentially,
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太阳系中留下的都是宇宙的残骸
the rest of the solar system is made up of the debris,
就像面包屑
like the crumbs,
你喝完咖啡杯子里剩下的残渣
the dregs in the bottom of your coffee cup.
大约经过10万年太阳形成于“太阳星云”之中
Our sun formed over the course of about 100,000
大约经过10万年太阳形成于“太阳星云”之中
years in what's called a solar nebula,
太阳星云就像是一个炙热的充满一缕缕灰尘和气体的摇篮
which is like a fiery cradle of wisps of dust and gas.
然后太阳星云开始压缩成一颗恒星
Then the solar nebula began to compress into a star,
可能是受到附近超新星的触发
probably triggered by a nearby supernova
这同样非常有效地将更重的元素抛撒在太阳系中
gassythat also, usefully, peppered the solar system
这同样非常有效地将更重的元素抛撒在太阳系中
with even more heavy elements.
然后由于这颗恒星吸收了太阳系中几乎所有的物质
And then, as the sun slurped up like almost
然后由于这颗恒星吸收了太阳系中几乎所有的物质
all of the matter of the solar system,
压力使其中心部位的温度急剧上升
pressure made the core of the sun heat up
太阳就形成了
and it came to life.
氢原子和氦原子通常的聚合反应开始发生
The usual fusion of hydrogen and helium began to happen
并一直持续的发生着
and continues to happen,
这很棒
which is nice
因为如果不这样
because otherwise
地球将会是极度寒冷一片死寂的景象
the Earth would be extremely cold, and- and also very dead. 那么我们怎么知道这一切都是真的呢？
So how do we know all of this is true?
好的听一听The Brain Scoop的Emily怎么说
Well, let's talk to Emily, from The Brain Scoop.
好吧一个很好的证据
Well, a good piece of evidence
是来自那个时间段的施工现场留下的瓦砾
is the construction site rubble from that time.
陨石形成了一种化石记录
Meteorites form a sort of fossil record.
陨石落在地球上
Meteorites fall to Earth
一些陨石是星云尘埃中的原始碎块
and some of them are primitive clumps of nebular dust. 细致的研究表明它们大约有45.68亿年的历史
Careful investigation reveals them to
细致的研究表明它们大约有45.68亿年的历史
be about 4.568 billion years old.
重点是铁60元素的形成只有两种可能的环境
The point is there can only be two
重点是铁60元素的形成只有两种可能的环境
environments where Iron-60 came from.
一种是产生于年龄非常大的红巨星的内部
One is inside of a very old giant red star,
另一种是产生于超新星
and the other is within a supernova.
老年红巨星会远离星星形成一片星系
Elderly red giants move away from
老年红巨星会远离星星形成一片星系
star forming regions in the galaxy;
而太阳的周围并没有这种星系
chances are, the sun wasn't formed near one of those. 所以更有可能的是
So it's much more likely that
太阳是受到附近超新星爆炸的触发而形成的
our sun's formation was triggered by a supernova blast. 所以在早期
So in the early days,0
太阳的高温将大量气体物质从内太阳系推了出去
the heat from the sun blasted lots of gassy materials1 太阳的高温将大量气体物质从内太阳系推了出去
away from the inner regions of the solar system,2
包括水星金星地球和火星
encompassing Mercury, Venus, Earth, and Mars,3
更远则达到木星现在的位置
further out in the vicinity of where Jupiter is now;4 这里的温度足够低于是挥发性气体能够聚集
it was cold enough for volatile gasses to hang around5 甚至变成液体或固体
and even become liquids or solids.6
所以内太阳系的行星比如地球是岩态行星
That's why the inner planets like us are rocky,7
而其他行星木星土星天王星和海王星都是气态巨行星
and the outer planets, Jupiter, Saturn, Uranus, and8
而其他行星木星土星天王星和海王星都是气态巨行星Neptune are all these humongous gas giants.9

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