与摩根·弗里曼一起穿越虫洞（2010）

Through The Wormhole With Morgan Freeman S02E03

Part 5 April 19, 2021, 2:34 p.m.

时间比宇宙还年长
that time is older than the Universe --
它在大爆♥炸♥之前就存在了
it was here before the Big Bang,
它在宇宙终结后还将存在
and it will be here after the Universe ends.
他认为他能够证明这它
And he thinks he can prove it
通过仔细观察光子的
by looking closely at how particles of light behave
长距离行为
over long distances.
物理学的核心规律之一规定
One of the core laws of physics states
光速是每秒186,282英里
that light travels at 186,282 miles per second.
如果时间是假象
If time is an illusion,
那真的就会是在宇宙各个角落
then this will be true everywhere in the Universe,
并没有我们所看到的物质存在了
no matter where we look.
但如果时间是真实存在的
But if time is real,
那就有可能物理定律会随着
it's possible that the laws of physics have changed
宇宙的年长而改变
as the Universe has aged.
若是如光速这样的基本物理定律
If a basic law of physics such as the speed of light
并不适用于宇宙的最古老部分的话
doesn't hold true out in the oldest part of the Universe,
那么我们将会知道物理学自宇宙诞生以来
we'll know that physics has evolved
已经演变了
since the Universe was born,
因而时间不能是假象
so time can't be an illusion.
会有某些实验的
There should be some experiments
这样如果你很敏感地观察的话
where, if you look very sensitively,
或许光速并不具有普遍性
maybe the speed of light is not Universal.
这样的实验有正在进行的
And there are such experiments which are being done.
费米太空望远镜
The Fermi Space Telescope
就是这样一个实验
is one such experiment.
费米将记录伽马射线暴
Fermi records gamma-ray bursts --
怪异的能量暴发
strange blasts of energy
来自宇宙的最远端
from the farthest reaches of the Universe.
这些爆发给我们机会去检查物理规律
These bursts give us the chance to check out the laws of physics
在130亿年前的模样
as they were 13 billion years ago.
试想有两个光子从100亿光年远的
Imagine two photons race out of a gamma-ray burst
伽马射线暴竞相闯出来
10 billion light-years away.
其中一个光子获得的能量大于另一个
One photon bursts with more energy than the other.
在我们这部分宇宙里
In our part of the Universe,
两个光子会以完全相同的速度穿行
both photons will travel at exactly the same speed.
但若是光的物理性质
But if the physics of light are different
在较老部分的宇宙间有所不同
in an older part of the Universe,
李认为较高能量的光子
Lee believes the higher-energy photon
应该稍稍落后
should fall slightly behind.
平衡的打破将会在那里
It would break down at the point where,
100亿年之后
after 10 billion years,
其中之一将会一秒或二秒或三秒领先
one of them would be a second or two or three seconds ahead,
但那足以被检测到
but that's enough to be detected.
即使是100亿年之一秒
Even one second worth over 10 billion years --
我们也能检测到
we can detect that.
费米发出的伽马射线暴的数据
The gamma-ray burst data from Fermi
会在接下来几年里送达
will come in over the next few years.
李可能很快就有他的证据了
Lee may soon have his proof
那就是130亿年前的现在
that the now of 13 billion years ago
这是不同于我们的现在
is truly different from our now,
因而时间必定是真实的
and therefore, time must be real.
物理定律随着时间而改变的确凿证据
Conclusive proof that the laws of physics change over time
将会解决这个争论
would settle the debate
时间究竟是真实还是假象
over whether time is real or an illusion.
但还是留下了一个大问题未予解决
But it still leaves a big question unanswered --
为什么会有时间呢？
why is there time?
理论上物理学似乎并不需要时间
In theory, physics doesn't seem to need time,
然而我们自我感觉穿行其中
and yet we feel ourselves moving through it.
如果时间不是我们头脑里天生的
If time wasn't born in our minds,
那么它又是从哪里来的呢？
then where did it come from?
肖恩·卡罗尔认为他有了答案
Sean Carroll thinks he has the answer.
但是它需要邪恶孪生宇宙
But it takes an evil-twin Universe
与后退的时间一道才能使其奏效
with backward-flowing time to make it all work.
关于时间如何运作的理论大量充斥于
Theories abound about how time works,
宇宙间和我们的头脑里
in the Universe and in our minds.
但就是有一位难得一见的物理学家提出了问题
But it's a rare physicist who asks the question,
为什么会有时间呢？
"Why is there time?"
如果时间不是我们人类发明的东西
If time isn't something we humans invented,
那它又是从何而来的呢？
then where did it come from?
肖恩·卡罗尔认为他知道
Sean Carroll thinks he knows.
肖恩是一位理论物理学家
Sean is a theoretical physicist
供职于加州理工学院
at the California Institute of Technology.
时间是实实在在的东西
Time is real.
我们每天都在用它证据在我们身边比比皆是
We use it every day. The evidence is all around us.
然而作为科学家
But as scientists,
我们对时间的真正意义思考得越多
the more we think about what time really means,
它就越扑朔迷离
the more mysterious it becomes.
肖恩接受常识性的想法
Sean accepts the common-sense idea
即时间是往前移♥动♥的从过去到未来
that time moves forward from the past to the future,
就像箭头一般
like an arrow.
但为何时间会有方向？
But why does time have a direction?
肖恩认为答案
Sean believes the answer is closely tied
与焦作熵的东西息息相关
to something called entropy.
让时间成为特别的是物理学定律
What makes time special is a law of physics,
热力学第二定律
the second law of thermodynamics.
第二定律基本上说
The second law essentially says
随着时间的推移熵在增大
that as time goes on, entropy increases.
熵告诉我们情况有多凌乱
Entropy is telling us how messy things are,
宇宙中的情况有多无序有多混乱
how disorderly, how chaotic things are in the Universe.
而在过去
So in the past,
若是你一路回到早期的宇宙
if you go all the way back to the early Universe,
那是非常有序的
it was very organized.
那就像是这些精巧排列的
It was like this delicately arranged configuration
台球
of billiard balls.
随着时间的推移就像是我们在打台球一样
As time goes on, it's like we're playing pool --
首先我们要做的
the first thing we do...
是我们要增加宇宙的混乱
...Is we increase the chaos of the Universe.
宇宙间时间的推移是个整体
As time goes on in the Universe as a whole,
无序熵升高了
disorderliness, entropy goes up.
因为宇宙的突然面世
Since the explosive birth of the Universe,
熵的增大就决定了
the increase of entropy is the reason
为什么过去不同于未来
why the past is different from the future...
为什么会有时间箭头
Why there is an arrow of time...
为什么我们记得过去
Why we remember the past...
为什么我们会变老
Why we grow older...
为什么进化会是这种方式
Why evolution happens the way it does.
这一切都是源于这个熵的增大
It's all because of this increase of entropy.
那奥秘何在呢？熵随着时间而提高
So, where's the mystery? Entropy goes up as time goes on.
但有趣的是
But interestingly,
在支撑我们周围一切的
in the fundamental laws of physics
基本物理定律中
underlying everything around us,
过去与未来之间并无差异
there is no difference between the past and the future.
流传给我们的定律不管是牛顿
The laws handed down to us by Isaac Newton,
爱因斯坦乃至量子力学
Albert Einstein, even in quantum mechanics,
你都无法区分
you have no distinction
一个方向的时间与另一个方向的时间的差异
between one direction of time and the other.
所以如果你有一个非常简单的物理系统
So, if you have a very simple physical system,
比如就两个台球
like just two billiard balls,
当你将一个撞上另一个
when you knock one into the other...
一个方向的时间
...There is no difference
与另一个并无差别
between one direction of time and the other.
你可以回放影像
You could play that movie backwards,
它会看上去很正常
it would look perfectly normal.
只有当我们碰到复杂的宏观系统时
It's only when we get to complicated, macroscopic systems
过去与未来之间就有差异了
that there's a difference between the past and the future.
当我们把许多台球放在台球桌上时
When we have lots of balls on the billiard table,
情况就发生在时间的一个方向上
things happen in one direction of time
而不是其它方向
but not the other.
或者还是当台球厅里形势失控之时呢
Or when all hell breaks loose in the pool hall.
好现在我们热闹了
So, now we have noise,