了解宇宙是如何运行的（2010）

How the Universe Works S08E05

Part 5 Jan. 30, 2022, 2:58 p.m.

泰格马克:一开始人们说这种奇怪的东西
Tegmark: So, first people said
weird stuff like that
根本不可能存在
just totally can't exist.
但是另一种被我们认为
But then another kind of
weird stuff
不可能存在的奇怪的东西，暗能量
that we were told couldn't
exist, dark energy,
却被证明是存在的
turned out to actually exist.
所以现在我们不再那么快，那么武断
So now we're not so quick
and fast and loose anymore
轻易地说，“哦，我们确定它不存在”
to just say, "oh, we're sure
that can't exist."
也许有一天我们可能会发现
narrator: Someday we may
discover a substance
有一种负能量的物质，可以打开虫洞
with negative energy, opening up
the possibility of wormholes
并使穿越时间成为可能
and of travelling backwards
through time.
但也许有另一种方式可以穿越到过去——
But there may be another way
to travel to the past --
通过控制时间本身
by controlling time itself.
泰勒:时间本身就有可能让你
Thaller: Time itself may be
something you can
弯曲和拉伸的
bend and stretch.
时间可能有不同的版本
There may be different
versions of time.
所以在某些方面，时间旅行
So in some respects, time travel
may be every bit as real
可能和我们最疯狂的
and every bit as strange
科幻幻想一样真实而奇怪
as our wildest
science fiction fantasies.
♪
时间旅行激发了科幻小说中
narrator: Time travel inspires
incredible journeys of
令人难以置信的旅行，而回到过去
science fiction,
and traveling to the past
将是终极的假期
would be the ultimate vacation.
如果我能穿越到过去
If I could time travel
into the past,
我很想体验一下罗马帝国
I would love to experience
ancient rome
鼎盛时期的古罗马
at the height
of the roman empire.
我将穿越130亿年的过去，观察我们的星系
I would travel 13 billion years
in the past, and I would watch
如何形成
our galaxy form.
塞勒:嗯，我可以告诉你，如果我是一个时间旅行者
Thaller: Well, I can tell you
if I were a time traveler,
我很想去参加史蒂芬·霍金的派对
I would love to show up
for stephen hawking's party.
但这真的可能吗？
But is this
actually possible?
我们能回到过去吗？
Can we ever travel back
into the past?
如果我们能回到过去
Narrator: If we could travel
back in time,
可能会有无尽的可能性
the possibilities
would be endless.
但倒向时间的旅行也会引起
But backwards time travel
also causes mystifying
令人困惑的时间悖论
temporal paradoxes.
即使在科幻小说中
Even in science fiction,
时间旅行也充满了悖论
time travel is
all about paradoxes.
你有可能影响你自己的过去吗？
Is it possible that
you can influence your own past?
最简单的说法就是
And the most simple way
of putting this
祖父悖论
is the grandfather paradox.
如果你能回到过去，杀死你的祖父
Narrator: What if you could go
backwards in time
会怎么样？
and kill your grandfather?
那样的话，你的父母是怎么出生的？
In that case, how could
your parents have been born?
你又是怎么出生的？
How could you have
ever been born?
布洛克:但如果你从未出生过，那你就不存在
Bullock: But if you were never
born, then you didn't exist.
你是怎么杀死你祖父的？
How did you kill
your grandfather?
你只是在原地打转这没有任何意义
You just run in circles.
It doesn't make any sense.
它在逻辑上是不可能的
It's logically impossible.
似乎宇宙法则不允许你
It seems like the laws of
the universe will not allow you
穿越回过去
to travel back in time.
但也许有个漏洞
But maybe there's a loophole.
有一种方法可以让我们回到过去
Narrator: There could be a way
to travel back in time
而不用制♥造♥矛盾
without creating a paradox
这多亏了空间和时间的联♥系♥
thanks to the way that space
and time are linked.
一旦你相信了四维时空
Once you believe in
four dimensional spacetime,
你就开始把现实概念化为
you begin to conceptualize
reality as the whole
整个四维的东西
four dimensional thing,
然后你就把它叫做大块宇宙
which you then call
the block universe.
它就像一个四维的物体
It's like a four dimensional
block of stuff.
不同的切片代表不同的时间时刻
The different slices
are different moments of time.
[发动机运转]
[ engine revs ]
在大块宇宙里
narrator: In the block universe,
过去、现在和未来共存
the past, present,
and future coexist.
如果你能跳出这个框架
If you could step outside
of this entire framework
看到这个大块宇宙
and see this block universe,
你就能看到宇宙的整个历史就在你面前
you would see the entire history
of the universe
从时间0一直到时间无穷大
from time zero to time infinity
sitting in front of you.
从一亿五千万年前漫游地球的恐龙到未来数百年
Narrator: From dinosaurs roaming
the earth 150 million years ago
殖民太阳系的人类
to humans colonizing
the solar system
再到2009年霍金
hundreds of years in the future
为时间旅行者举办的派对
and hawking's party for time
travelers back in 2009.
在大块宇宙中，所有的历史同时存在
In the block universe, all of
history exists simultaneously.
天体物理学家保罗·萨特解释道
Astrophysicist
paul sutter explains.
你可以把大块宇宙想象成一个电影胶卷
You can think of the blog
universe as a film reel
过去和未来都已经存在
where the past
and future already exist.
它们只是在同一部影片上的画面帧
They're just frames
on this same film.
所有的帧都已经存在了
All the frames already exist.
它们就在那里
They're just right there.
但是我们以特定的顺序和特定的方向
But we experience them
in a particular order
经历它们，这是基于，你知道的
and in a particular direction
based on, you know,
一个特定的转动把手
a particular turn of the handle.
就像转动电影胶卷的把手
Narrator: Just like a handle
turning a film reel,
时间从过去流向未来
time flows from past to future.
但既然时间中的每一刻
But since every moment
in time exists
都是作为一帧存在于这个胶卷的某个地方
as a frame somewhere
on this reel,
那么我们当然可以去拜访它们
then surely we can visit them.
塞勒:如果大块宇宙的想法是真的
Thaller: If the idea of
the block universe
那么时间旅行就会变得更容易理解
is really true, that makes
time travel more understandable
也更有可能性
and more possible.
我们只需要想个办法
We just need to find a way
to get to different
从不同的角度切入
parts of this reel.
要做到这一点，我们必须找到
Narrator: To do that,
we have to find a way
一种穿越时间的方法
to travel through time.
我们知道行星和黑洞会扭曲时空
We know planets and black holes
curve spacetime.
但爱因斯坦的方程揭示了真正的大质量物体
But einstein's equations reveal
that really massive objects
在彼此周围移♥动♥时，会将时空拖入一个循环
moving around each other
can drag spacetime into a loop.
我们宇宙中最有可能发生
The regions of our universe