你并不在你以为的那个地方：英语精读讲义

Look around you.

看看你的周围。

Where are you?

你在哪里？

Where is this place you're occupying?

你占据的这个地方到底在哪里？

Somewhere in a room, maybe in a city,

也许在某个房间里，也许在某座城市里，

on a continent, on a planet orbiting a star in a galaxy among billions.

在某块大陆上，在一颗绕着某颗恒星公转的行星上，而这颗恒星又处于数十亿个星系中的一个。

But where is all of that?

但所有这些又都在哪里呢？

While this may feel like a daft question,

虽然这听起来像是个傻问题，

it turns out that the concept of an absolute position is something humans made up. 表達脈絡

但事实证明，绝对位置的概念完全是人类虚构的。

In a nutshell, 習語

简而言之，

the universe is a big bag of space that has things in it.

宇宙就像一个装满了东西的空间大口袋。

If someone removed all these things,

如果有人把这些东西全都拿走，

the stars and planets and black holes and dust,

那些恒星、行星、黑洞和尘埃，

there would just be empty space left.

留下的就只有空无一物的空间。

In empty space, the concept of having a position loses all meaning. 短語搭配

在虚空之中，拥有一个位置的概念失去了所有意义。

Empty space is uniform, the same everywhere.

虚空是均匀的，到处都一样。

The space we occupy is not like a stage under our feet. 習語

我们占据的空间并不像脚下的舞台。

We can't mark specific points or staple something to space-time as an anchor. 習語

我们无法标记特定的点，也无法将某物钉在时空上作为锚点。

Without things, there is no position.

没有了事物，就不存在位置。

We are really ever only at a position in relation to something else,

我们实际上永远只能相对于其他东西而拥有一个位置，

which also means that things we take for granted 習語

这也意味着我们理所当然认为的那些事情

like up and down are actually relative too.

比如“上和下”，其实也是相对的。

Okay, let's fill the universe up with things again

好了，让我们重新把东西装满宇宙，

and try to find out where you are right now 短語動詞

然后试着弄清楚你现在究竟在哪里

relative to everything else.

相对于其他所有事物而言。

Let's start this video at a familiar place 表達脈絡

让我们从一个熟悉的地方开始这段视频，

and then get increasingly weird.

然后情况会变得越来越诡异。

From your perspective,

从你的视角来看，

the world is seemingly flat and you can move in three dimensions.

世界似乎是平坦的，你可以在三维空间中移动。

It's what physicists call a frame of reference, 用詞

这就是物理学家所说的“参考系”，

the perspective you have of the universe

这是你观察宇宙的视角，

and how you see things moving around you,

以及你看待周围事物如何移动的方式，

where your up and down is.

以及你的“上下”在何处。

Your frame of reference is correct for you,

你的参考系对你来说是正确的，

but not for the rest of the universe.

但对宇宙的其他部分则不然。

Around 5 km from you,

在距离你大约5公里的地方，

where the horizon begins,

即地平线开始的地方，

the ground noticeably curves away from you.

地面会明显地向下弯曲。

If you could see through the ground, 語法

如果你能透视地面，

you'd see people from below or sideways.

你会看到下方或侧面的人。

But they don't fall down off the planet

但他们并没有从这颗星球上掉下去，

because gravity doesn't actually pull them down.

因为引力并没有真正把他们“往下拉”。

Down is an illusion of your reference frame.

“向下”只是你的参考系产生的一种错觉。

To Earth's reference frame,

对地球的参考系而言，

gravity just pulls in.

引力只是在向内拉。

But for humans, there is an up and down

但对人类来说，“上和下”是存在的，

because within our frame of reference, that just makes sense,

因为在我们的参考系里，这就说得通，

which is also why we think that the planet itself has an up and down,

这也是为什么我们认为这颗行星本身也有上下、

north and south,

南北之分，

and we made our maps accordingly.

我们还据此绘制了地图。

But an observer looking at the solar system might disagree.

但观察太阳系的观测者可能会不同意。

Our maps make sense to us because we're used to them, 語法

我们的地图对我们来说合理，是因为我们习惯了它们，

not because they are correct.

而不是因为它们是绝对正确的。

Okay, so this is step one.

好了，这是第一步。

Your position on what feels like a flat surface,

你在一个感觉像是平面的表面上的位置，

but is actually a sphere.

但实际上是一个球体。

But this sphere is always moving,

而这个球体总是在运动，

never staying in one position.

从不曾停留在某一个位置。

Earth is orbiting a star,

地球正在绕着一颗恒星公转，

the sun at the center of the solar system.

即位于太阳系中心的太阳。

While we usually imagine this as pretty orderly,

虽然我们通常把这一切想象得井然有序，

someone looking at us from the outside would see something pretty messy.

但从外部观察我们的人会看到相当混乱的景象。

To see this more clearly,

为了看得更清楚些，

we'll exaggerate all these movements.

我们将夸大所有这些运动。

This is not to scale. 短語搭配

此图并未按实际比例绘制。

First of all, our orbit really is an ellipse,

首先，我们的轨道其实是一个椭圆，

so we spend half the year sinking a little bit closer to the sun, 語法

所以我们有半年的时间会稍微靠近太阳一点，

speeding up,

速度加快，

and half the year rising up a bit and slowing down.

另外半年则会稍微远离一点，速度放慢。

And the ellipse itself changes its shape every 100,000 years too.

并且这个椭圆本身每十万年也会改变一次形状。

And in another cycle of 112,000 years,

在另一个11万2千年的周期中，

the ellipse itself is drifting,

这个椭圆本身也会发生漂移，

which at least creates a beautiful shape.

这至少创造出了一个美丽的形状。

In the end, we get an orbital path

最终，我们得到了一条公转轨迹，

that looks like a wobbly circle with wavy edges.

看起来就像一个边缘呈波浪状、摇摆不定的圆。

And it gets worse

事情变得更复杂了，

as the moon now starts to mess things up too. 短語動詞

因为月球现在也开始来搅局。

As the moon is a pretty massive thing,

由于月球是个质量相当大的天体，

it pulls on Earth.

它对地球有引力作用。

Both objects orbit their common center of gravity

这两个天体都围绕着它们共同的重心运转，

that lies around 4,700 km off to the side of Earth's core.

这个重心位于偏离地球核心约4700公里的地方。

In practice, this means that as the moon orbits Earth, 表達脈絡

实际上，这意味着当月球绕地球公转时，

it's jerking Earth around a bit, 短語動詞

它在轻轻拉扯着地球，

enough to make it jiggle.

足以让地球产生晃动。

Okay, so you're standing on the surface of a rotating planet

好了，所以你正站在一颗自转行星的表面上，

that is jiggling around the sun in an elliptical orbit

它在椭圆轨道上围绕太阳晃动，

that changes a bit every year.

这个轨道每年都在发生微小的变化。

But who's to say the Earth is right? 習語

但谁说地球的视角就是正确的呢？

From the perspective of the sun,

从太阳的视角来看，

the plane of the solar system is arbitrary.

太阳系的平面是任意界定的。

It's defined as the plane the Earth orbits in 短語搭配

它被定义为地球公转所在的平面，

because that is convenient for us.

因为那样对我们来说很方便。

In reality, the other planets are just a little bit inclined

实际上，其他行星相对于我们的平面，

with respect to our plane. 短語搭配

都有着些许倾斜。

From their point of view, 表達脈絡

从它们的角度来看，

we're the ones with a slightly bent orbit.

我们才是那个轨道略微弯曲的家伙。

But this isn't it, far from it. 習語

但这还差得远呢。

The solar system as a whole 短語搭配

太阳系作为一个整体，

is orbiting the center of the Milky Way galaxy.

正在绕着银河系的中心公转。

If we look at the Milky Way,

如果我们观察银河系，

we can clearly make out a galactic plane 短語動詞

我们能清晰地分辨出一个银道面，

in which the solar system orbits the center every 230 million years.

太阳系就在这个平面上每2.3亿年绕中心公转一圈。

But of course, it's not that simple.

但当然，事情没那么简单。

First of all, the plane of the solar system

首先，太阳系的平面

is not aligned with the plane of the galaxy.

并没有与银河系的平面平齐。

Nothing really is,

其实没有什么东西是真正平齐的，

just like the planets in the solar system orbit the sun on their own planes, 語法

就像太阳系里的行星在各自的平面上绕太阳公转一样，

so do all the stars orbiting the galactic center.

绕银河系中心运转的所有恒星也是如此。

The solar system as a whole is tilted about 60 degrees towards the galactic plane,

太阳系整体向银道面倾斜了大约60度，

speeding through space at almost a million kilometers per hour.

正以将近一百万公里的时速在太空中穿梭。

Someone in the center of the galaxy

身处银河系中心的人

would see the orbits of the planets moving through space in a helix shape,

会看到这些行星的轨道在太空中呈螺旋状移动，

which you can imagine as a corkscrew motion on the tilted plane of the solar system 表達脈絡

你可以把它想象成在倾斜的太阳系平面上进行的开瓶器式运动，

relative to the plane of the galaxy.

它是相对于银道面而言的。

This orientation in space means that sometimes

在太空中的这种方位意味着有时，

the planets are sort of in front of the sun 語氣意圖

在太阳绕银河系核心公转时，

as it orbits around the galactic core.

这些行星有点像是运行在太阳的前方。

Let's just look at this for a moment.

让我们稍微欣赏一下这个画面。

There is a strange and eerie beauty

我们行星和太阳在太空中穿行的方式，

about how our planets and the sun move through space.

带着一种怪异而神秘的美。

Do you feel a bit dizzy?

你觉得有点头晕了吗？

It gets worse.

更糟的还在后头。

This is still not the whole story

这仍然不是故事的全貌，

because the mass of the galactic disc

因为银盘的质量

is constantly pulling on the solar system too.

也在不断地牵引着太阳系。

Like a drunk dolphin,

就像一头喝醉的海豚，

we're diving down and shooting up hundreds of light-years

我们每次绕行时都会穿过银道面10次，俯冲而下又向上冲出几百光年，

through the galactic plane 10 times every orbit

在太空中穿梭，

along arcs thousands of light-years long.

沿着数千光年长的弧线前行。

We haven't mapped this motion out completely 短語動詞

我们还没有完全绘制出这种运动的轨迹，

as it takes the solar system tens of millions of years to go up and back once,

因为太阳系上下穿梭一次需要数千万年，

and well, humanity is not that old.

嗯，人类的历史还没有那么久远。

Let's look at your relative position again,

让我们再来看看你的相对位置，

on a planet tilted towards the sun,

在一颗向太阳倾斜的行星上，

jiggled around by the moon,

被月球拉扯得晃动，

in a solar system tilted towards the galactic plane,

处在一个向银道面倾斜的太阳系中，

moving forward in a helical shape,

以螺旋形状向前移动，

diving up and down through the plane.

并在银道面上下来回穿梭。

Hmm, but where is up in a galaxy?

那么，在星系里，“上”又在哪里呢？

At this point,

到了这一步，

the frame of reference becomes a bit arbitrary and pointless

参考系变得有些武断且毫无意义，

because of the nature of the universe at this scale.

因为在这个尺度上，宇宙的本质就是如此。

The Milky Way is part of a galaxy group

银河系属于一个星系群，

that appears to be part of greater structures

而这个星系群似乎又属于更大的结构，

like the Laniakea supercluster,

比如拉尼亚凯亚超星系团，

which itself is part of the gigantic Pisces-Cetus supercluster complex,

它本身又属于庞大的双鱼-鲸鱼座超星系团复合体，

and finally a galactic filament that spans hundreds of millions of light-years

最终是一条跨度达数亿光年的星系纤维，

in all directions and orientations.

向各个方向和方位延伸。

Someone looking right at us from that far away

从那么远的地方直直地看着我们的人，

will only see the end of greatness.

将只会看到“宏大之结（End of Greatness）”。

All stuff appears homogeneous, the same everywhere.

所有的物质看起来都是均匀的，到处都一样。

Just like with empty space, when everything looks the same,

就像在虚空中一样，当一切看起来都一样时，

who's to say anyone's view is better than anyone else's?

谁又能说谁的视角比别人的更好呢？

We've reached the end of our little exercise in cosmic humility. 習語

我们这场宇宙谦卑之旅已经抵达终点。

Let's make the journey backwards again,

让我们再次开启倒放的旅程，

from the indescribably large to the really large

从无法言喻的庞大回到真真切切的大，

to our galactic home,

回到我们的银河家园，

to our galaxy,

回到我们的星系，

to the solar system

回到太阳系，

diving up and down through the Milky Way,

正在银河系中上蹿下跳，

to the jiggle of existence,

回到那摇晃不定的存在，

and finally back to you right now watching this video.

最后回到此时此刻正在看这部视频的你。

If this is all a bit much, 習語

如果这一切让你觉得信息量有点大，

don't feel bad. 語氣意圖

别感到难过。

The scale of the universe is brain-crushing

宇宙的尺度极其考验大脑，

and trying to keep track of how everything is oriented 短語搭配

试图去追踪所有事物的方位，

or decide where the best up and down is is hard. 語法

或是决定哪里是最好的“上下”，确实很难。

But it doesn't really matter

但这其实并不重要，

because it doesn't change where you are.

因为它并不会改变你所在的位置。

You're already in the best spot you possibly could be,

你早已身处你所能处于的最好的位置，

right here, right now. 短語搭配

就是此时，此地。

For all you care,

就你所关心的而言，

nothing can stop you from being right at the center 習語

没有什么能阻止你身处

of your own little universe.

你自己的小宇宙的正中心。