与摩根·弗里曼一起穿越虫洞（2010）

Through The Wormhole With Morgan Freeman S05E07

Part 1 April 19, 2021, 3:03 p.m.

每时每刻我们都能感受到它
We feel it every moment of our lives.
但对物理学家来说
But for physicists...
这是宇宙最古老的谜团
It is the oldest unsolved mystery of the cosmos.
为什么引力使得物体之间相互吸引？
Why does gravity make everything attract?
最前沿的理论带给我们了意外的答案
Cutting-edge theory is closing in on unexpected answers.
引力是否是另一种力的表现形式
Could gravity be another force in disguise...
一个全息现实的影子
A shadow of a holographic reality,
或是虚幻的涟漪？
or a rippling mirage?
我们，地球，太阳和其他恒星
Do we, Earth, the Sun, and the stars
真的有重量吗？
really have weight?
难道引力只是一个幻觉？
Or is gravity an illusion?
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（S05E07）
Through The Wormhole With Morgan Freeman (S05E07)
引力真的存在吗？
Is Gravity an Illusion?
太阳的引力使地球
The gravitational pull of the sun
围绕太阳运行而不会脱离轨道
keeps Earth from flying off into space.
地球的引力使我们牢牢地站在地面上
Earth's gravity keeps us firmly planted on the ground.
这一切都看起来那么真实
This all seems real enough.
科学家们则深入到宇宙的结构之中
But scientists are peering deep into the fabric of the universe
发现引力
and are discovering that gravity...
也许并不是它看起来的这样
...may not be what it seems to be.
我们觉得真实的东西会是虚幻的吗？
Can something feel real but not actually be real?
在我成长的日子里
There were some days growing up
有些时候没什么事可做
when there just wasn't anything to do.
我们就会玩一些简单的游戏
So we would play simple games
比如扔石头
like target practice with rocks.
引力一直发挥着作用
Gravity always worked.
无论我扔出什么东西，它都会掉在地上
No matter what I dropped, I always expected it to fall.
物理学家对引力有着自己的见解
Physicists have their own expectations about gravity.
他们认为引力是一种基本力
They believe it to be a fundamental force,
是宇宙的基本组成结构
an intrinsic cog in the machinery of the universe.
但实验物理学家内吉斯·马瓦瓦尔瓦
But experimentalist Nergis Mavalvala
并不认为这一切都是理所当然的
isn't taking anything for granted.
一种基本力——比如引力
So, a fundamental force that -- like gravity,
用来描述有质量物体间的相互作用
that describes how massive objects interact
我们认为引力是真实存在的
should be true anywhere you look in the universe.
艾萨克·牛顿发现任何有质量的物体
Isaac Newton showed that every object with mass
都会互相吸引
attracts every other object with mass.
两个物体质量越大，距离越小
The greater the mass and the closer they are,
它们之间的万有引力就越大
the greater the gravitational attraction.
两百多年后
Over 200 years later,
阿尔伯特·爱因斯坦解释了为什么会这样
Albert Einstein explained why this happens.
空间和时间互相交织形成时空
Space and time are interwoven into a fabric called spacetime.
爱因斯坦认为时空可以弯曲
Einstein believed that spacetime could bend.
这种时空形变产生了引力
This distortion is what we experience as gravity.
这是他如何理解有质量物体间的
And that's how he understood that objects with mass
相互吸引
attract to each other.
物体随时空弯曲运动
They follow the curvature of spacetime.
爱因斯坦对引力的描述
So Einstein's picture of -- of gravity was
表明质量是时空扭曲的表现
that mass tells spacetime how to curve,
时空的扭曲
and then the curvature of spacetime
告诉物体如何运动
tells mass how to move.
爱因斯坦也预测了
Einstein also predicted
当有质量的物体运动时
that when all objects with mass move,
会引起时空结构中
they trigger tiny gravitational ripples
微弱的引力波动
in the fabric of spacetime.
引力波会波及我们头上的天空
Gravitational waves should permeate the heavens above us.
内吉斯认为如果这些波足够大
Nergis believes we should be able to detect those waves,
我们就能够检测到它们
if they are big enough.
如果我往池塘中间扔出一个苹果
So if I drop an apple in the middle of a pond...
我在岸边检测水波强度
And I try to detect the ripple at the shore,
这基本是不可能的
it's not going to make it.
这个波过于微弱了
It was too small of a wave.
对内吉斯来说，幸运的是
Luckily for Nergis,
天空中引起波动的物体
bodies much more massive than apples
比苹果大得多
cause a stir in the heavens.
牛逼！哇哦！
Awesome! Whoa!
整个宇宙中
Around the cosmos,
剧烈的引力事件
intense gravitational events,
比如星系之间的碰撞
like the collision of galaxies...
或是巨星的爆发
...or the explosions of giant stars...
都会向着地球发出
...should be sending massive volleys
引力波信♥号♥♥
of gravitational waves towards Earth.
内吉斯发明了一种检测它们的方法
Nergis has created a way to detect them
这需要像迈克·兰德里这样的同事的帮助
with the help of collaborators like Mike Landry.
内吉斯和迈克
Nergis and Mike
是美国国家科学基金会建造的
are part of the largest experiment ever built
最大的实验室成员之一
by the National Science Foundation.
它就是
It is known as
引力波天文台（激光干涉引力波天文台）
the Laser Interferometer Gravitational Wave observatory, or L.I.G.O.,
在这个庞然大物中
in this behemoth,
激光束射向两个
laser beams fire down two vacuum tubes
以L型排布的真空管
arranged in an "L" shape.
每个臂都有4公里长
Each arm is 4 kilometers long.
激光束在每个臂中测量扰动的精度
The laser beams can measure the length of each arm
可以达到一个原子宽度的
with an accuracy of better than 1 millionth
一百万分之一
of the width of an atom.
如果距离我们有500兆兆英里远的
If a gravitational wave from any intense cosmic event
某个剧烈宇宙事件产生了引力波
up to 500 trillion trillion miles away
经过了地球
passes through the Earth,
管子中的空间就会波动
the space inside the tubes will ripple.
激光束就可以检测到变化
The lasers will detect the change,
提示铃就会响
and the alarm bells will ring.
对天空将近十年的聆听
After almost a decade of listening to the heavens,
引力波天文台没有检测到
L.I.G.O. picked up the sound...
任何明显信♥号♥♥
...of crickets.
在引力波天文台运行初期
We didn't observe a gravitational wave
我们并没有观察到引力波
in the initial science runs of L.I.G.O.
内吉斯，迈克和引力波天文台的数千位科学家
Nergis, Mike, and the thousands of scientists at L.I.G.O.
还有一招
Have one more shot.
他们正尝试使用先进的设备
They're working on advanced upgrades
来使引力波天文台的检测敏感程度增加十倍
that will increase L.I.G.O.'s sensitivity tenfold.
但这仍不能保证他们就能够获得引力波信♥号♥♥
But there's no guarantee they'll ever get a signal.
如果使用如此先进的引力波天文台
Well, if we don't detect gravitational waves
还检测不到引力波的话，我就要哭了
with advanced L.I.G.O., well, first, I'll cry.
但之后我觉得现在的结果同样令人兴奋
But then, I think, it's actually very exciting either way.
如果我们检测不到引力波
If we don't see gravitational waves,
那么一场新的革命就会开始
then it's going to start off a different kind of revolution,
人们就会努力去思考
where there'll be a lot of head-scratching
“到底大自然还有什么是我们不了解的？”
about, "what is it about nature we don't understand?"
内吉斯对此充满希望
Nergis is hopeful.
事实上，2014年三月，一组宇航员
In fact, in march of 2014, a group of astronomers
声称他们检测到了
claimed to have detected gravitational waves
由大爆♥炸♥产生的引力波
produced by the big bang.
而一些科学家认为
But some scientists take
引力波天文台并未监测到任何信♥号♥♥
the deafening silence at L.I.G.O.
恰好说明引力也许并不是基本力
as evidence that gravity may not be a fundamental force.
苹果成熟后向地面掉落
When an apple falls to the earth,
也许是其他原因造成的
something else could be pulling it down.
物理学家们认为宇宙万物
Physicists believe that everything in the universe,
包括一股我们称作力的能量
even the pulse of energy that we call force,
都是由粒子构成的
is made from particles.
引力也不例外
Gravity should be no exception.
兹维·伯尔尼是一位粒子物理学家
Zvi Bern is a particle physicist
他有着非常丰富的想象力
with a very active imagination.
他正在设想如果把高尔夫球
He's imagining what a game of mini golf would look like
压缩到亚原子粒子的大小、
if the balls were shrunk
并遵循量子力学规律后
to the size of subatomic particles
应该如何玩这场迷你高尔夫球呢？
and ruled by the laws of quantum mechanics.