(单词翻译:单击)
- I know every scientist understands that we cannot see the entire universe right now.
每个科学家都明白，我们现在无法看到整个宇宙。
And that's because there's such a thing that we quantify as the observable universe.
这是因为我们把它量化为可观测的宇宙。
The universe has existed, we think, since the Big Bang, about, say, 13.8 billion years.
我们认为，自从大爆炸以来，宇宙已经存在了大约138亿年。
So as you look farther and farther out into space, you necessarily have to look back in time.
因此，当我们在太空中看得越来越远时，我们必然要回头看时间。
If something is a million light years away from you, like the Andromeda galaxy is about two million light years away,
如果某样东西离我们有100万光年，比如仙女座星系离我们大约200万光年，
the light that you see through binoculars tonight, as you look up at the Andromeda galaxy left two million years ago.
那么我们今晚通过双筒望远镜看到的星光是200万年前留下的。
We now have instruments that see so far, we can actually look back to about 400,000 years after the Big Bang.
我们现在有仪器可以看得很远，我们实际上可以回看大爆炸后约40万年的景象。
We can see so far out into space that the light has taken that long to get to us.
我们可以看到很远的空间，而光要花很长时间才能到达我们这里。
The whole idea of the Big Bang has been given I think a real disservice.
我认为整个大爆炸的概念被赋予了一种误解。
There are so many misconceptions, and certainly, one of the biggest misconceptions is that people think that scientists feel that the Big Bang came out of nothing.
有许多误解存在，最大的误解之一是人们觉得科学家认为大爆炸是无中生有。
I mean, how did all of this energy and all of this matter that made up the universe, you're saying it just came out of nothing.
所有这些能量和物质是如何构成宇宙的，还是说它只是凭空出现的。
No, I don't think any scientist actually believes that.
不，我认为任何科学家不会真的相信这一点。
The problem is when you think about the condition the universe was in at that point, I mean, take our observable universe, right?
问题是，当考虑到宇宙那时的状况，即可观察到的宇宙，对吧？
I mean, you can look from one side of the universe to the other, you'll back 13.5 billion light years or more.
你可以从宇宙的一边看向另一边，你会回到135亿光年前甚至更早。
All of the stuff that we see was actually compressed into a space smaller than an atom, volume smaller than an atom.
我们看到的所有东西实际上都被压缩到一个比原子还小的空间，体积比原子还小。
We don't have the physics that describes how that would work.
没有物理学来描述这是如何实现的。
That is so much mass, so much energy and so little volume, at this point, there wasn't even mass, just basically pure energy, that right now, our physics doesn't go there.
它的质量和能量很大，但体积很小，在这一点上，它甚至没有质量，基本上只是纯能量，现在，我们的物理学尚未研究到这一点。
As we get a better idea about how gravity works under very extreme circumstances, huge energy densities, we may have some idea what set off the Big Bang, and possibly what came before the Big Bang.
当我们了解重力在非常极端的情况下、在巨大的能量密度下如何工作时，我们可能知道什么引发了大爆炸，并知道大爆炸之前的一些东西。
So today we actually have telescopes that are so powerful, they can see back to a time about 400,000 years after the Big Bang.
因此，今天我们实际上有非常强大的望远镜，它们可以看到大爆炸后大约40万年的景象。
That's amazing, we can see so far away in space that the light has taken that long to get to us, nearly 13.8 billion years.
这是令人叹为观止的，我们可以看到如此遥远的太空，光需要很长时间，将近138亿年才到达人类世界。
And when we look back to that time, the universe looks very different.
而当我们回过头来看那个时候，那时的宇宙看起来非常不同。
For one thing, it's very hot. (chuckles) It's actually about as hot as the surface of the sun.
首先，它非常热。(它实际上和太阳的表面一样热。
And it's so dense and hot that we actually can't see any farther.
它的密度很高很热，以至于我们实际上无法看到更远处。
Literally, in any direction you look around the sky, anywhere you look, if you look to that distance,
实质上，你从任何方向环顾天空，你看到的任何地方，如果你看向那个距离，
you see the universe as it was at that time, 400,000 years after the Big Bang, and everything becomes just hot hydrogen gas.
你会看到宇宙在那个时候的样子，也就是大爆炸后40万年的样子，一切都变成了热氢气。
That's incredible. But what that means is that there's a limit.
这真是不可思议。但这意味着有一个极限。
There's a bubble around us that we can see just because there's been time for light to come to us from those areas.
在我们周围有一个气泡，我们能看到只是因为已经有时间让光从那些地方来到我们身边。
Think about my arm being the universe before the Big Bang, in some kind of state that we can't even describe through modern physics.
把我的手臂比作是大爆炸之前的宇宙，它处于某种我们甚至无法通过现代物理学描述的状态。
The entire observable universe that we can see now used to be a tiny volume of it, maybe an atom in my arm.
我们现在能看到的整个可观测的宇宙曾经是它的一个小小的部分，也许是我手臂上的一个原子。
One atom expanded and became the entire observable universe that we see.
一个原子扩大后成为我们看到的整个可观测的宇宙。
But that's not the whole universe.
但这并不是整个宇宙。
There are trillions of atoms in my arm.
我的手臂里有数万亿个原子。
Each one of those could expand to actually be its own entirely observable universe.
其中的每一个都可以扩展成它自己的完全可观察的宇宙。
So we can't tell yet how big the universe was before the Big Bang, or even what shaped the universe is,
所以我们还不能说宇宙在大爆炸之前有多大，甚至不能说宇宙是什么形状的，
because all we're seeing is a tiny little bit of it that expanded to become everything that we see, but that's not the whole universe.
因为我们所看到的只是它的一小部分，它扩展成为我们所看到的一切，但那不是整个宇宙。
That's our observable universe.
那是我们可观察到的宇宙。
There's far more out there than what we can see.
外面的世界远比我们能看到的要多。
