了解宇宙是如何运行的（2010）

How the Universe Works S08E05

Part 7 Jan. 30, 2022, 2:58 p.m.

普莱特:我们目前对宇宙的理解是
Plait: Our current understanding
of the universe
宇宙有一个时间零点
is that there was a time zero.
宇宙诞生的那一刻
There was a moment that
the universe came into being,
就是大爆♥炸♥
and that is the big bang.
大爆♥炸♥似乎是
The big bang seems
to have been
一个非常低的熵态
an incredibly low entropy state.
一切都非常有序，非常密集，非常热
Everything was very ordered,
very dense, and very hot.
所以除了从这个状态增加熵外
So there was really nowhere
for entropy to go
真的没有别的选择了
but to increase from that state.
在时间零点，宇宙从一个
Narrator: At time zero,
the universe expanded
高度有序稠密的能量点开始膨胀
from a highly ordered
dense speck of energy.
38万年后，第一个原子形成了
380,000 years later,
the first atoms formed.
气体逐渐开始聚集在一起
Gradually gas began
to clump together.
大约2亿年后
Something like
200 million years later
第一批恒星形成了
that the first stars formed,
然后这些恒星在那之后形成了星系
and then those formed into
galaxies sometime after that.
随着宇宙的老化和膨胀
Narrator: As the universe ages
and expands, it becomes
它变得越来越无序
more and more disordered.
星系之间的距离越来越远
Galaxies move further
and further apart.
数万亿年后，无序将主宰一切
In trillions of years,
disorder will rule.
恒星建造的气体将会耗尽
Star building gas will run out.
不会有新的恒星形成
No new stars will form.
当最后一颗恒星死亡时
When the last stars die,
宇宙将变得寒冷和黑暗
the universe will become cold
and dark.
特伦布雷:坦白地说，我们的宇宙
Tremblay: The accelerated
and continual and forever
正在加速、持续、永远地膨胀，这可能会导致一个
expansion of our universe
might make for a, frankly,
令人沮丧的结局
depressing end.
总有一天，宇宙中最后一颗恒星
There will come one day when
the very last star
会熄灭，就是这样
in the universe just
fizzles out, and that is it.
大爆♥炸♥也许可以解释
Narrator:
The big bang may explain
为什么时间似乎是朝一个方向流动的
why time seems to flow
in one direction,
从过去到现在
from the past
through the present
再到未来，一直到最后一个时刻
and to the future, right down
to the last detail.
宇宙中熵的增加解释了为什么
The rise of entropy in
the universe explains why
你可以用一个完整的鸡蛋来炒一个鸡蛋
you can scramble an egg
from a whole egg,
但是用一个炒好鸡蛋还原成一个完整的鸡蛋
but it's a little harder
to make a whole egg
就有点难了
from a scrambled one.
熵对于想要成为时间旅行者的人来说
Narrator: And entropy could be
a big problem
可能是个大问题
for wannabe time travelers.
时间的年代意味着随着时间的推移
The era of time means
that things get
事情变得更加混乱
more chaotic over time.
所以如果你回到过去
So if you were to go back
in time,
就打破了熵定律
it breaks that law of entropy.
泰勒:事实上，它的熵，就是我们
Thaller: And its entropy,
in fact, the reason why
不能穿越到过去的原因
we cannot travel into the past,
that that is getting back
那就是回到宇宙中
to a part of the universe
能量不同、无序程度不同的
where the energy itself
was different,
那一部分
the level of disorder
was different.
也许熵定律要求我们
Maybe this law of entropy
不断向未来前进
requires us to keep
moving into the future.
时间之箭似乎是在通往过去的
Narrator: The arrow of time
seems to be another
棺材板上的又一颗钉子
nail in the coffin
for traveling to the past.
但一些科学家认为可能存在一种变通方法
But some scientists think
there could be a work around.
[时钟滴答作响]
[ clock ticking ]
时间旅行者可能会在量子领域
time travelers might travel
to the past
回到过去
in the quantum realm.
虽然在我们的宏观世界里
Though in our
macroscopic world,
我们没有经历过双向的时间旅行
we don't experience time travel
in both directions,
但在量子领域里
it could be that
the quantum realm
这可能是允许的
may allow that to be possible.
而量子时间旅行
Narrator:
And quantum time travel
可以改变我们对现实的所有认知
could change everything
we know about reality.
♪
我们在一个方向上体验时间的流动——
narrator: We experience the flow
of time in one direction --
向前
forwards.
时钟的指针永远不会倒转，打碎的鸡蛋永远碎着
Clock hands never reverse,
broken eggs stay broken.
[咝咝声]
[ sizzling ]
人们只有在收到邀请后
and people only attend a party
才会参加派对
if they're invited
before it takes place.
但在宇宙中有一个地方
But there is a place
in the universe
时间之箭可能双向运行——
where this arrow of time
might run both ways --
由量子力学控制的亚原子领域
the subatomic realm,
ruled by quantum mechanics.
在量子力学中，我们知道
In quantum mechanics,
we do know that
亚，亚，亚，亚原子世界
the sub, sub, sub, sub
atomic world
是一个非常奇怪的地方
is a very strange place.
微观粒子构建了
Narrator:
Microscopic particles build
我们在宇宙中看到的一切
everything
we see in the universe.
夸克、轻子和玻色子，这些微小的粒子
Quarks, leptons, and bosons,
tiny building blocks
都有自己的规则——量子力学定律
that play by their own rules --
the laws of quantum mechanics.
在量子世界里，亚原子粒子
In the quantum world,
subatomic particles
可以穿墙而过，也可以突然出现或消失
can travel through walls
or pop in and out of existence.
但量子力学定律
But the laws
of quantum mechanics
有一个更奇怪的性质
have an even stranger property.
它们似乎是可逆的
They appear to be reversible.
在量子力学中，就我们目前所知的
In quantum mechanics,
there is no difference between
物理定律而言，移♥动♥到未来
moving to the future
and moving to the past
和移♥动♥到过去并没有什么区别
as far as we currently know
in the laws of physics.
在量子领域
Narrator: In the quantum realm,
时间之箭可能会失效
the arrow of time
may break down.
2019年3月，俄♥罗♥斯♥科学家
In March 2019,
russian scientists
对此进行了测试
put this to the test.
利用量子计算机，他们模拟了一个电子
Using a quantum computer,
they simulated an electron
在不到一秒的时间里向后移♥动♥
travelling a fraction
of a second backwards in time.
该团队计算出这种向后运动
The team calculated
that this backward motion
可以在现实世界中自发发生
can spontaneously happen
in the real world.
虽然在138亿年的宇宙历史中
Though perhaps only once in
the 13.8 eight billion year
可能只有一次