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大爆炸证据:冰冻希格斯、冰镇啤酒、还有引力波 – 译学馆
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大爆炸证据:冰冻希格斯、冰镇啤酒、还有引力波

Big Bang Evidence: Frozen Higgs, Frozen Beer, and Gravity Waves | Lawrence Krauss

我们对于宇宙最初的认识不断地改进 我很高兴
Our picture of the earliest moments of the universe has been evolving, and I’m happy
在某些方面 它得到了比以前更多的实证支持
to say, in some sense has more empirical support than it did before.
希格斯场的发现意味着场可以冻结于真空中
The discovery of the Higgs field implies that you can get fields that freeze in empty space.
它是我们对宇宙初期演变的认知的核心部分
And that’s a central part of what we think happened in the very early universe.
如果我们能够探测到宇宙大爆炸产生的引力波
And if we can detect gravitational waves from the Big Bang we’d have a window on the universe
那么我们就有途径去研究一万亿亿亿亿分之一秒时的宇宙
back to a time when it was a billionth of a billionth of a billionth of a billionth
回答关于宇宙起源的问题
of a second old, answering questions about the origin of the universe as we know it—ideas
我的新书中有提到这些猜想 例如书中描述了一些
that I speculated upon in my last book, for example—for which we have new evidence that
关于这些猜想的新的证据
I’ve described in my new book.
但是在宇宙早期 宇宙的温度 能量以及其中的粒子都非常极端
But because the temperature of the universe and the energies and particles were so extreme
那时 整个宇宙塌缩到一个比原子更小的尺度上
at that early time—when the entire visible universe was contained in a region that was
在这个尺度上 宏观与微观相差无几
smaller than the size of an atom—there’s a wonderful symbiosis between large scales and small scales smaller
如果我们能够探测到我提及的早期宇宙的信号
And if we can probe the early universe back to a time that I described we’ll actually
那么 我们就能够探测到比大型强子对撞机所能获得的还要小的尺度上的物理现象
be probing physics on scales that are much smaller than we can see at the Large Hadron
比我们用现有的最高能的加速器所能获得的尺度(或能量)还要小(大)12个数量级
Collider, 12 orders of magnitude smaller in scale (or higher in energy) than we can probe with our highest-energy accelerator now.
为了建造一个能够直接探测到如此大能量的加速器我们必须有一个
To build an accelerator that would directly probe those energies, we would have to have
不仅包含26千米长的大型强子对撞机
an accelerator that’s not just 26 km around, as the Large Hadron Collider is, but whose
同时 还要包含一个周长要为日月距离的加速器
circumference is the earth-moon distance
我们穷尽一生(可能永远)也无法完成如此规模的加速器
and that’s not going to be built in our lifetime (and probably ever)
因此 我们只能依靠宇宙自身去给予我们这些信息
So we may have to rely on the universe to give us new information, and that’s why we’re
这就是我们要去探测这些信号的原因
looking for such signals.
当宇宙的年龄是万亿亿亿亿分之一秒时
When the universe was a billionth of a billionth of a billionth of a billionth of a second
我们现有的图像表明:有一个与希格斯场相似的场冻结于空间中
old our current picture suggests: A field very similar to the Higgs field froze in space,
我们称之为亚稳态
but it was in what is called a metastable state.
就像…你要举办一个啤酒聚会 但是直到聚会马上就要开始了
Sort of like… if you have a beer party and you put beer in the freezer because you forgot
你才想起你忘了把啤酒冰镇一下 所以你将它放入了冷冻格 但是在聚会当中
to until the few minutes before the party, and then during the party you forget that
你又忘了在冷冻格中的啤酒 一段时间之后你才把它拿出来
it’s in the freezer, and you take it out later.
你会发现它依旧是液态的 但是当你打开它时 它突然变成了固态
And it’s there—liquid—and you open it up, and suddenly it turns to ice, and the
然后瓶子爆裂:啤酒就处于亚稳态
bottle cracks: The beer is in a metastable state.
只有处于高压下 它才能在那样的温度下不冻结
At that temperature it would rather be frozen except it’s under a high pressure.
当你释放了压力时 它突然冻结 并且释放出大量的能量
The minute you release the pressure it freezes instantaneously, releasing a lot of energy.
当我们的宇宙冷却下来时同样的事情发生了:一个场冻结了
As our universe cooled we think the same thing happened; basically a field got frozen but
但是这并不是个好的选择 随着宇宙的冷却—嗙!—就像那啤酒瓶一样
in the wrong configuration, and as the universe cooled, suddenly—boom!— like those beer
它改变了自身的状态 释放出大量的能量
bottles, it changed its state, releasing a huge amount of energy, creating the hot Big
产生了大爆炸
Bang.
现在 有趣的是 当它处于亚稳态并且储存着能量时
Now the interesting thing is, while it was in that metastable state and storing energy,
广义相对论告诉我们:如果有个储存着能量的真空场
general relativity tells us that if you have a field in empty space that’s storing energy
那么它的引力效应为排斥而非吸引
it produces a gravitational effect that’s repulsive, not attractive.
所以有那么短暂的瞬间 引力场为排斥场 然后宇宙大爆炸开始
So during that brief time gravity is repulsive, and the expansion of our universe started
膨胀得越来越快 (我们认为)宇宙会在一百亿亿分之一秒内
speeding up faster and faster and faster, and the size of our universe (we think) increased
将尺度扩大到原来的10的30次方倍
by a factor of 10 to the 30th in scale, or at least 10 to the 90th in volume, in a time
而体积则至少膨胀为原来的10的90次方倍
interval of a billionth of a billionth of a billionth of a second.
这意味着在很短的时间内 它由一个原子的大小膨胀至一个篮球的大小
That means it went from the size of an atom to the size of a basketball in a short time,
正是由于这剧烈的膨胀导致了遍及整个宇宙的基本的性质:
and that rapid expansion produced characteristics which pervaded the universe today: The fact
我们观测到的宇宙近乎平坦涨落与宇宙微波背景辐射
that our observed universal looks flat, the fluctuations, and the cosmic microwave background
都来自于膨胀时的量子涨落
radiation all came from quantum fluctuations that happened during inflation.
膨胀是第一原则 它从根本上解释了
Inflation is the only First Principles idea that in principle explains why our universe
为什么宇宙会是这样的
looks the way it does.
值得庆幸 它不需要量子引力
And what’s wonderful about it is it doesn’t require any exotic ideas of quantum gravity
以及其它我们还没有建立的理论来提供支持 它完全是基于我们现有的
or theories we don’t have, it’s based on ideas that are central to our current understanding
对粒子物理的标准模型的认知 仅仅是标准模型的外推
of the standard model of particle physics, just extrapolating them somewhat.
所以 这个很好的解释 即使我们很难相信宇宙大爆炸曾经发生过
So it’s very well-motivated; even though it is hard to believe that it could have happened,
但是我们认为它发生过
we think it did.

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视频概述

演讲者:Lawrence M.Krauss

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翻译译者

ckan

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视频来源

https://www.youtube.com/watch?v=E0Wqo7706R8

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