宇宙时空之旅：未知世界（2020）

Cosmos: Possible Worlds S01E09

Part 2 Aug. 24, 2022, 10:55 a.m.

Because he assumed that the many overlapping colors would
会导致惠根斯想象的那种光波
result in the same light wave that Huygens imagined,
称为"干涉图样"
called an interference pattern.
他迫使单一色彩的光穿过两道缝隙
He forced that single color of light to travel through
想看光会在最后一张纸板上
two separate slits to see what kind of pattern the light
形成哪一种图样
would make on that last piece of cardboard.
如果光是粒子你会预见在对面的纸板上
If light was a particle, you'd expect to see two distinct
见到两团明显的光
clumps of light on the opposite wall,
也就是每一个光粒子穿过缝隙后
where the individual particles of light ended up
停留的地方
after they passed through the slits.
然而结果并非如此
But that's not what happened.
纸板上出现了完全意想不到的图样
Instead, a completely unexpected pattern.
是两道水波重叠或彼此...
The one that two waves would make when they overlapped,
干涉后出现的那种图样
or interfered with each other.
所以那叫做干涉图样
That's why they're called an interference pattern.
杨证明了光实际上是一种波
Young had demonstrated that light was actually a wave.
牛顿这个科学史上最伟大的天才错了一半
That Newton, the greatest genius in the history of science was half wrong.
光并不是他自信满满宣称的粒子
That light was not a particle as he confidently proclaimed.
权威人士的论述在科学中没什么分量
There's a reason that arguments from authority
这是有原因的
hold little weight in science.
只有自然才能决定论述的正确性
Nature and nature only settles the argument.
而自然界的花招太多
And she has so many tricks up her sleeve,
只有无知者才会认为我们对自然界完全知晓
only a fool would ever consider our understanding of nature complete.
牛顿遗漏了某个重点
Newton had missed something fundamental.
令人意外但是最令人不安的部分还在后头
Surprising, but we haven't gotten to the really disturbing part yet.
托马斯·杨留下了一颗定时炸♥弹♥
Thomas Young left a time bomb with a long fuse.
导火线很长花了100年才烧尽并引爆
One that took 100 years to burn down before it exploded.
直到十九世纪末科学才研发出必要工具
It wasn't until the end of the 19th century that science
找到隐藏宇宙的开口
developed the necessary tools to find an opening to a hidden universe,
隐藏宇宙又充满更深奥的谜
a realm of deeper mystery.
你可以听到发现者为自己的成就惊呼
You can hear the discoverer's astonishment in his own account.
会有东西在乍看之下比这还无用吗
THOMSON: Could anything, at first sight,
这个物体极小
seem more impractical than a body which is so small that
其质量只占一个氢原子的一小部分
its mass is an insignificant fraction of the mass of an atom of hydrogen?
而氢原子本身已经非常小
Which itself is so small that
就算是聚集与全球人口一样多的数量
the crowd of these atoms equal
也是小的无法用当时科学已知的...
in number to the population of the whole world would be too small
任何方式被探测出来
to have been detected by any means then known to science.
那个声音那个将近100年前
That voice, that particular organization of
凝结在时间中的声波组织
sound waves frozen in time nearly 100 years ago,
属于约瑟夫·汤姆孙
belongs to J.J. Thomson.
他在回忆自己做阴极射线实验时发现电子的事
He's remembering his discovery of the electron in his cathode ray experiment.
他不断加热一个金属电极直到电极发射出一个电子
He had heated up a metal electrode until it spit out an electron.
又一个再一个
And another, and another.
史上第一次组成原子的基本粒子
For the first time, an elementary particle of
被人发现了
the atom was made visible.
科学闯入自然界的宝库
Science was breaking into nature's vault where she had
而那里藏着自然界最隐私的秘密
kept her most closely held secrets,
情况自此变得迷人不已
and that's when things got really crazy.
如果就连物质最小的单位原子
If even the smallest units of matter, atoms say,
都还有更小的组成例如电子
had even smaller components, such as an electron,
那么光是不是也一样呢
then could the same thing be true of light?
无法停止对光着迷的科学家
Scientists, in their never-ending fascination with light,
开始着手想办法
set out to devise ways of isolating smaller
把光分离成更小的单元
and smaller units of it.
后来证实这就是穿过镜子的通道
It proved to be the passage way through the looking glass.
在这道门槛后方的奇境中
It was the crossing of a threshold into a wonderland
已知的物理法则一概不适用
where the known rules of physics do not apply.
史上第一次科学家能够分离出光的最小单位
For the first time, they were able to isolate the tiniest unit of light,
单光子
a single photon.
并且把托马斯杨的双缝实验发展到全新境界
And to perform Young's double slit experiment on a whole new level,
可以追踪光穿过左右任一缝隙时的精确路径
tracing its precise path either through the right slit or the left slit.
我们要停在旁边从最好的角度观察
We'll pull over to the side of the road for the best possible view of which slit,
光子是从左边还是右边的缝隙
the right or the left,
抵达对面的墙壁
the photon passes through to get to the far wall.
左边右边
Left slit, right slit.
又是右边
Another right slit.
左边
Left slit.
如果我们观察上一整天
If we watched them all day long,
会发现模式是随机的
the pattern would be random.
穿过两边的光子大约各半
About half would go through either slit.
等一下
Wait a second.
波在哪里
Where are the waves?
杨氏干涉图样在哪里
Where is Young's interference pattern?
不可思议就从这里开始
This is where the weird begins.
我无法解释你即将看到的一切
I cannot explain to you what you're about to see.
因为地球上还没有人能理解
That's because no one on earth understands it yet.
如果你不能接受
If you can't live with that,
那你对稍后发生的事就不会满意了
then you're not gonna be happy with what lies up ahead.
在人类讨论过最小的可能规模
On the smallest possible scale that we've ever discovered,
即量子宇宙上仅仅是观察的行为就会改变结果
the quantum universe, the mere act of observation changes reality.
好光子一直来吧这次我们保证不去看
Okay, photons, keep on coming, and this time we promise not to look.
你绝对不会相信我们只要不去看光子
You're not gonna believe this, but we can change the pattern
穿过哪条缝隙就能改变对面
on the far wall simply by not watching which slit the
墙壁上的图样
photons pass through.
我知道听起来很扯但是至今做过的每一次实验中
I know it sounds crazy, but in every trial ever conducted,
结果都取决于实验是否在被观测
the outcome depends on whether or not the experiment was observed.
刚才我们没有看到干涉图样
So, the reason we didn't get the interference pattern
不是因为我们把光细分成单光子
earlier wasn't because we chopped up the light into single photons,
而是因为我们在观察光子
it was because we were observing which slit
穿过哪一条缝隙
the photons passed through,
可是光子怎么可能知道有人在观察
but how can a photon know if someone is watching?
光子没有眼睛
A photon doesn't have eyes.
也没有大脑
A photon doesn't have a brain.
它怎么知道自己正在被观测？
How could it know it was being watched?
你或许会理智地推断
You might reasonably conclude that a single photon is such
单光子体积极小要用复杂的科技才看得到
a tiny thing that it's very hard to see without using complex technology.
这种方法♥会♥破坏微弱的光子
This machinery does violence to the delicate photon.
令其发生变化但这还无法解释
It changes it, but that doesn't explain why photons
为何光子在我们观察时表现得像粒子但不观察时却像波
behave like particles when we're watching but waves when we're not.
如果光本质上是粒子
If light is fundamentally a particle,
那就不应该产生波形
then it should never create a wave pattern,
无论我们是否在观察光子
whether we're observing it or not.
单光子又怎么知道该在哪里就位
And how can individual photons know where to take their places,
光子群才会形成波的干涉图样？
so that as a group they create the interference patterns of waves?
这就是量子物理核心的一道令人气恼的难题
This is a maddening conundrum at the heart of quantum physics.
艾萨克·牛顿和克里斯蒂安·惠更斯
Isaac Newton and Christiaan Huygens were both
两人对的一样多也错的一样多
equally right and equally wrong.
光既是粒子又是波同时又二者皆非
Light is both a wave and a particle, and neither.
直到我们观察之前
Until we make an observation,
光子都以一种不确定的状态存在
the photon exists in a state of uncertainty,
受概率法则的控制
governed by laws of probability.
当我们观察它的时候
And when we do observe it,
它就变得完全不同
it becomes something completely different.
没有克里斯蒂安·惠更斯我们将迷失在量子宇宙中
We would be lost in the quantum universe without Christiaan Huygens.
他的概率理论即使在现在
His probability theory provides, even now,
都是我们理解量子现实的唯一关键
the only key we have to grasping the laws of quantum reality.
每一个粒子都以随机的运气
Every particle is at the mercy of random chance
与变换的概率主宰
and shifting probabilities.
思考这件事就像看着一个光学错觉
Thinking about it is like looking at an optical illusion,
一次只能掌握它的片刻
you can only grab hold of it for moments at
然后它就会变回原来的模样
a time before it pops back into something else.
在量子宇宙中有一个尚未探索的边界
In the quantum universe, there's an undiscovered
我们这个世界的法则在那里被取代
frontier where the laws of our world give way to the ones
新法则适用于我们所知的最小规模
that apply on the tiniest scale we know.
与我们的日常经历毫不相关
They're divorced from our everyday experience.
你要如何思考一个法则与我们不同的世界?
How can you think about a world that has different rules than ours?
这并不容易
It's not easy.
所以我要带你去一个地方
That's why I want to take you to this place where it's not
在那里不但会有剧烈改变还非变不可
only possible to make such a leap, it's mandatory.
那个世界跟我们很像