与摩根·弗里曼一起穿越虫洞（2010）

我们都在随时间无休息地前进
We're all marching relentlessly forward through time.
我们接受了时间根本停不下来
We accept that there's no way to get off this ride
也没法改变我们的命运
or to change our destiny.
但果真如此吗？
But what if that's not really true?
如果我们能向过去传送消息
What if we can send messages back in time...
收到
Copy that.
并改变已经发生的事件
...and change events that already happened?
未来能否回顾过去，改写现在？
Can the future reach back and rewrite the present?
时间可以倒流吗？
Can time go backwards?
空间，时间，生命本身
Space, time, life itself.
宇宙之谜，尽在穿越虫洞
The secrets of the cosmos lie through the wormhole.
与摩根·弗里曼一起穿越虫洞（S06E02）
Through The Wormhole With Morgan Freeman (S06E02)
时间可以倒流吗？
Can Time Go Backwards?
我们认为过去是一成不变的
we think of the past as being set in stone
未来则是一块白板，一切皆有可能
and the future as a blank slate where anything can happen.
但爱因斯坦的相对论
But Einstein's laws of relativity
模糊了我们的时间观念
blur our concept of time.
这位伟大的人曾说过
As the great man said,
过去、现在、未来之间的区别
the distinction between the past, present, and future
不过是顽固而持久的幻觉
is only a stubbornly persistent illusion.
如果所有的时间已经在这里了
If all of time is already out there,
我们能让时间的沙子反过来流淌吗？
can we make the sands of time flow the other way?
加州大学
Craig Callender
圣地亚哥分校的克雷格·卡伦德
of the university of California, San Diego
是一个研究物理学和认知科学的哲学家
is a philosopher who studies physics and cognitive science.
他很奇怪为什么我们体验到的时间
He wonders why we don't experience time
并非时间真正的样子
the way it really is.
我们通常认为我们的大脑
We ordinarily think of our brains
只是接收信息流
as just receiving this stream of information
并被动地传达给我们
and giving it to us in a passive way.
但是事实上，我们从来没有真正地透过表面
But, in fact, we never really look underneath the hood
看看真正发生了什么
and then see what really is going on.
你看着平滑移♥动♥的表针
When you look at a smoothly moving clock hand,
你的大脑可以让时间看起来像是停止和开始
your brain can make time appear to stop and start
当你的精神注意力转移的时候
whenever your mental focus changes.
如果你看着一个模拟时钟
If you look at an analog clock
你看着秒针的移♥动♥
and you're looking at the second hand as it's going around,
正如你用注意力抓住了它
just as you grab it with your attention,
秒针像是短暂地暂停了一样
the second hand seems to pause momentarily.
当你照镜子的时候
You also experience a pause in time
也会感受到时间的暂停
whenever you look in the mirror.
将你的目光从一只眼睛转移到另一只眼睛
Shift your gaze from one eye to the other,
你不会看到眼睛的运动
and you will never see either in motion.
大脑总是跟我们玩这些把戏
The brain is pulling all these tricks on us all the time.
我们的大脑通过扭曲时间帮助我们抓取世界的快照
Our brains distort time to help us take snapshots of the world
记忆重要的事件
and remember important events.
如果时间的概念被扭曲了，现实又是什么呢？
If our concept of time is distorted, what's the reality?
爱因斯坦的相对论
Albert Einstein's theory of relativity
试图解释时间是怎样工作的
attempts to explain how time truly works.
在他的观点里，时间是一个维度
In his view, time is a dimension
就像空间的三个维度一样
just like the three dimensions of space.
因此，他相信
And because of this, he believed
没有什么普遍意义上的“现在”
that there is no such thing as a single universal "now."
空间没有普遍意义上的“这里”，时间怎么会有呢？
Space has no single universal here, so why should time?
我们身在圣地亚哥
So, here we're in San Diego.
其他的地方——波士顿、伦敦、莫斯科
There are other places -- Boston, London, Moscow.
还有很多别的地方
There are all those other places.
我们看不见它们，但是知道它们存在
We can't see them, but we know they exist.
类似地，事物在时间中也是这样排列着
Similarly, things are laid out in time that way, too.
全部的时间已经存在
All of time already exists
和其他三个维度一起
alongside the other three dimensions.
在爱因斯坦对时间的描述中
In Einstein's description of time,
克雷格的动作，下水
Craig's actions of getting into the water,
划桨，上岸
paddling over it, and getting out
都和其他的动作共同发生
all happen alongside one another.
物理学家把这种
Physicists call this view of reality
全部时间和空间已经存在的现实观
where all of time and space already exist
叫做块宇宙
the block universe,
它看起来就像是这块蛋糕
and it looks like this cake.
令块的这一端作为大爆♥炸♥
So, let this end of the block be the big bang,
另一端作为宇宙的终结
this end of the block be the end of the universe.
全部的事件都排列在这里
All the events are there laid out.
有些事件可能是你的出生
So some of these events might be your birth.
有些事件可能是现在
Some of them might be right now.
有些事件可能是你的死亡
Some of them might be your death.
它们全都在这里
They're all there.
当然，我们不能一次看到整个块宇宙
Of course, we don't see the block universe all at once.
我们每个人从自己现在的切面经历宇宙
We each experience the universe as our own slice of now.
切面后面的一切成为我们的过去
Everything behind the slice becomes our past,
前面的一切代表我们的未来
and everything in front represents our future.
所以每一个观察者都有一个不同的切面
So each observer will have a different slice,
把宇宙切割成过去，现在和未来
carving it up into past, present, and future.
这把刀就是他们的现在
That knife will be their present.
但就像每个人的“这里”都不一样
But just as everyone can't have the same here,
不是所有人都有一致的“现在”
not everyone can agree on what now is.
或者换一种说法
Or to put it another way,
每一个人都有一个独特角度的“现在”切面
everyone has their own uniquely angled now slice.
考察你的现在切面，在地球上
Consider your own slice of now here on earth.
你的现在包括了夜空中的光线
Your now includes light in the night sky
来自附近的半人马座α星
from the nearby star Alpha centauri.
但那束光用了四年时间才到达你这里
But that light has taken over four years to reach you.
所以你的现在切面实际上是倾斜的
So your present slice is actually angled
包括了半人马座α星的过去
to include past events on Alpha centauri.
如果某个三体人正在看地球
For someone on Alpha centauri looking toward earth,
他们的切面包含了我们的星球上
their now slice includes events from four years in the past
四年前的过去
on our planet.
爱因斯坦表示
And Einstein is saying that
不同的切法没有区别
there's no distinguished cutting up of the cake.
都是一样合法的
They're all equally legitimate ways of cutting up everything.
这些切面会在时空中
And those slices will grab different events
抓取不同的事件
in the space-time manifold.
光线在几秒之一秒内就可以跑遍整个地球
Light zips around our planet in a small fraction of a second,
所以大脑骗我们在共享的“现在”上取得了共识
so our brains trick us into agreeing on a single shared now.
大脑还骗我们相信
And our brains also fool us into believing
时间是移♥动♥的，即便过去，现在和未来
that time is moving, even though the past, present, and future
共同存在
exist together.
克雷格认为这是因为我们的大脑
Craig thinks this is because our brains
把不同的现在切面串联在了一起
are stringing together individual slices of now,
像是电影的帧一样
like frames of a movie.
真正发生的，我想
What's really going on, I think,
是我们只有一个方向的记忆
is that we have memories only in one direction.
你得不到关于未来的记忆
You just can't get memories of the future.
你的记忆里有婴儿的你，成人的你，等等
So there's baby you, adult you, et cetera.
你的这个身份线程在时空中运行着
You have this thread of identity running through space-time.
这就是为什么感觉像是我在流动
That's why it feels like I'm flowing,
因为我在建立自我的故事
because I'm building up this story of the self.
块宇宙里没有什么是移♥动♥的
There's nothing really moving through the block.
我们对时间的感受显得是扭曲的，甚至是装配好的
Our sensations of time appear to be distorted, even fabricated,
那麽我们能换个方式看待时间吗？
so can we learn to see time differently?
时间从不停歇
Time never stops.
但大脑一次只能记录一个瞬间
But our brains can only register one moment in time --
我们管这个瞬间叫现在
the moment we call the present.
如果所有的时间同时存在
If all of time does exist at once,
我们就不能改变我们的视角
couldn't we change our viewpoint of time
看到我们的未来吗？
and maybe see our own future?
吉姆·哈特尔是加州大学
Jim Hartle is a physicist
圣塔芭芭拉分校的一名物理学家
at the university of California at Santa Barbara.
他花了几十年去琢磨
He spent decades trying to wrap his head around
爱因斯坦的相对论
Einstein's theory of time.
在狭义相对论中，并没有过去、现在、未来
There isn't a notion of past, present, and future