(单词翻译:单击)
There were lots of things scientists believed a century or two ago that might sound weird to us today.
科学家们一两百年前相信的事情可能对今天的我们来说有点儿奇怪。
For one thing, they once thought atoms looked like plum pudding.
首先，他们曾认为原子像葡萄干布丁。
But over time, as researchers have done more experiments and developed new theories,
但随着时间的推移，研究人员做了许多实验并开发了新理论，
those ideas have evolved into the science we know today.
这些想法已经发展成为我们今天所知的科学了。
And one of the most game-changing experiments ever was what's known as the Michelson-Morley Experiment,
其中最具颠覆性的实验就是所谓的迈克尔逊·莫雷实验，
not because of what it did find, but because of what it didn't.
这不是因为它发现了什么，而是因为他们没有发现什么。
See, physicists used to think that all of space and time was filled with what they called the aether:
物理学家们曾认为所有的时间和空间都充满以太，
an invisible material that wasn't interacting with anything, but was giving light its speed.
以太是一种无形的物质，不与任何物质反应，但能给光加速。
No one had ever detected this aether, but scientists figured it had to be there,
没有人探测过以太，但科学家们确定它存在，
they knew that light acted like a wave, and waves seemed to need a material to travel through.
他们知道光就像波浪一样，似乎需要物质传递。
Throughout the 19th century, evidence was piling up that light was a wave,
在整个19世纪，越来越多的证据表明光是一种波，
it reflected like a wave, it interfered with itself like a wave...
它像波浪一样反射，像波浪一样干扰着自己。
So it would make sense for light to get around like other waves, too, by moving particles back and forth.
所以光像其他波一样，通过粒子的来回移动四处传播就能讲通了。
In ocean waves, for example, the water molecules move up and down.
例如，在海浪中，水分子上下移动。
And in sound waves, air particles move back and forth.
在声波中，空气粒子来回移动。
So it would make sense for light to be moving around something,
所以光在物体周围移动也说得通，
even if it was invisible and physicists called that something the aether.
即使那是隐形的、被物理学家们称为以太的物质。
In the spring of 1887, in Cleveland, Ohio,
1887年春天，在俄亥俄州的克利夫兰，
Albert Michelson and Edward Morley set up an experiment to learn more about the aether,
阿尔伯特·迈克逊和爱德华·莫里建立了一个实验，以了解更多以太的知识。
by looking for the effects of something called the aether wind.
方法是寻找以太风的效果。
You know how when you try to yell into a particularly strong gust of wind, your voice won't get very far,
你知道，当你试图冲进一股特别强的风时，你的声音不会太远；
but if you yell with the wind, it'll go much farther?
但如果你对着风大喊时，声音会传得更远吗？
Well, scientists assumed that as Earth moved through this aether,
科学家们假设地球穿过以太时，
it would create a similar kind of wind,
会产生类似的风，
but one that would affect the speed of light from Earth's perspective.
但从地球的视角上看，它会影响光速。
So Michelson and Morley set up beams of light in a way that should have given them different speeds,
于是迈克尔逊和莫雷发射了
depending on whether they were traveling with, against or perpendicular to the aether wind.
与以太风平行或垂直的光束，产出了两个速度本应不同的光。
They then bounced the two beams off of mirrors so that they eventually reunited with each other,
然后让两道光束在镜子上反射，最终两者汇聚，
and predicted the beams would arrive at slightly different times,
他们还预测光束会在不同的时间到达，
since they'd been sped up or slowed down by the wind.
因为以太风会使它们加速或减速。
But the result? One of the greatest failed experiments of all time.
但是结果呢？这是有史以来最失败的实验之一。
There seemed to be no difference between the two beams.
两道光束似乎没什么不同。
It was like Earth wasn't moving through any kind of aether at all.
就像地球没有穿过以太一样。
Over the next few years, physicists tried to figure out how that could possibly make sense.
接下来的几年，物理学家们试图弄明白其中的原理。
Some said that the experiment just wasn't accurate enough,
有人说实验不够精确，
and tried repeating it with better and better equipment.
并用更好的设备重复实验了，
But they still didn't find anything.
但没发现任何东西。
Eventually, they had to accept that it seemed like there was no such thing as an aether.
最终，他们不得不接受这样的事实：宇宙似乎根本就没有“以太”这种物质。
Instead, light is just different from other waves.
相反，光与其他波不同。
Turns out that the speed of light isn't affected by an invisible aether,
事实证明，光速不受无形以太的影响，
and light speed through a vacuum is always the same.
真空中的光速总是一样的。
Space and time will even bend themselves to fit, which is where Einstein's Special Theory of Relativity comes in.
空间和时间甚至会屈服于光，这就是爱因斯坦狭义相对论的出处。
He helped put all these pieces together, showing that physics could work even without the aether.
他帮忙把所有的因素整合起来，证明物理没有以太也能工作。
It just meant that completely mind-bending things had to be happening, like time slowing itself down.
这就意味着会发生完全令人费解的事情，比如时间会自己慢下来。
And unlike with the aether, experiments have shown that Einstein was right.
与以太不同，实验证明了爱因斯坦是对的。
Meanwhile, more physicists were working on some of the other questions raised by the fact that the aether didn't exist.
与此同时，更多物理学家根据以太不存在的事实，正在研究一些其他问题。
Mainly: if light wasn't like a regular wave, what was it?
其中主要有：如果光不是普通的波，那么它是什么？
After a whole lot of experimenting, they realized that even though light did act like a wave sometimes,
他们经过大量实验认识到，即使光有时是波，
it also acted like a particle, what's known as the wave-particle duality.
但它也像粒子，这就是我们所知的波粒二象性。
It was another brain-melting idea,
这是另一个颠覆性的想法，
and one that eventually led to another whole new field in physics, quantum mechanics, the science of the very small.
它最终带来另一个全新的物理领域——量子力学，一个研究微观世界的科学。
So, the Michelson-Morley Experiment might have banished the aether to the history books.
因此，迈克尔逊·莫雷实验可能已经把以太驱逐出了历史书。
But its failure also led to some of the most important ideas in science.
但它的失败也带来了一些最重要的科学思想。
Thanks for watching this episode of SciShow Space,
感谢您收看本期的太空科学秀，
and thanks especially to our patrons on Patreon who help make this show possible.
特别感谢Patreon对本节目的大力支持、
If you want to help us keep making episodes like this,
如果你想我们继续制作此类节目，
just go to patreon.com/scishow to learn more.
就登陆patreon.com/scishow了解更多信息吧。
And don't forget to go to youtube.com/scishowspace and subscribe!
不要忘了登录youtube.com/scishowspace点击订阅哦！
