評論
打印
And many of the questions that we might have about the universe at large scales,
我們關于宇宙在宏觀上有很多問題，
such as, how does gravity work?
比如，引力是怎么起作用的？
might be answered by studying these systems.
這些問題可能可以通過研究這些系統來解決。
So that was very big.
所以這就是“非常大”。
The second things is very hot.
第二個特點是“非常熱”。
Okay, if I take an image of a galaxy cluster,
如果我拿出一幅星團的照片，
and I subtract away all of the starlight,
去掉其中所有的星光，
what I'm left with is this big, blue blob.
留下的是這個巨大的藍色的一團。
This is in false color.
這個顏色不是真的。
It's actually X-ray light that we're seeing.
事實上這是X光。
And the question is, if it's not galaxies,
問題是，如果不是這些星系，
what is emitting this light?
那么是什么在發出這X光呢？
The answer is hot gas,
答案是高溫氣體，
million-degree gas in fact, it's plasma.
一百萬度的氣體，事實上是等離子。
And the reason why it's so hot goes back to the previous slide.
溫度如此之高的原因要回到前一張幻燈片。
The extreme gravity of these systems is accelerating particles of gas to great speeds,
這些系統的超強引力將氣體粒子加速到非常高的速度，
and great speeds means great temperatures.
而高速則意味著高溫。
So this is the main idea,
這是主要的想法，
but science is a rough draft.
但是里面的科學還不太明晰。
There are many basic properties about this plasma that still confuse us,
關于等離子氣體，還有很多基本性質的問題仍讓我們困擾，
still puzzle us,
仍然是謎團，
and still push our understanding of the physics of the very hot.
但它正在推進我們對超高溫物理的理解。
Third thing: probing the very small.
第三個問題是：研究“極小”。
Now, to explain this, I need to tell you a very disturbing fact.
為了解釋這個，我要說一件很讓人困擾的事實。
Most of the universe's matter is not made up of atoms.
宇宙的大部分物質不是由原子構成。
You were lied to.
你們以前被騙了。
Most of it is made up of something very, very mysterious,which we call dark matter.
宇宙大部分是一種非常神秘的物質，我們稱為暗物質。
Dark matter is something that doesn't like to interact very much,
暗物質不太與周圍發生作用，
except through gravity,
除了通過引力，
and of course we would like to learn more about it.
理所當然的我們希望對其了解更多。
If you're a particle physicist,
如果你是粒子物理學家，
you want to know what happens when we smash things together.
你會想知道當我們撞擊物體的時候發生什么。
And dark matter is no exception.
暗物質也不例外。
Well, how do we do this?
那么，我們怎么做呢？
To answer that question,
為了回答這個問題，
I'm going to have to ask another one,
我要問另一個問題，
which is, what happens when galaxy clusters collide?
那就是，當星團碰撞的時候會發生什么？
