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Most physical objects in everyday life maintain the same identity
日常生活中的大多数物体，
whether we're interacting with them, or not.
无论我们是否与它们互动，都保持着同一性。
Like, a baseball is a baseball whether you're holding it in your hand
就像，棒球就是棒球，
or it's flying through the air.
不管是在你手里还是在空中划过。
Even electrons are electrons whether they're part of an atom
甚至电子也不例外，
or flying freely through interstellar space;
无论它们是作为原子的一部分还是在宇宙空间自由飞行；
they have the same mass, same charge: they are electrons.
它们有相同的质量，相同的电荷：它们是电子。
But neutrinos, those weird, super light, super fast,
但是中微子粒子，这些怪异的、超光速的、
electrically neutral, hard-to-interact-with particles - they are identity-agnostic.
电中性的、难以与粒子相互作用的粒子，人们对这种粒子的特征是持有不可知的态度。
Neutrinos have different identities depending on
中微子有不同的特征，
whether they're interacting with other particles, or traveling freely,
取决于它们是否与其他粒子相互作用，或自由移动，
and on top of that their identities can change over time!
除此之外，它们的特征可以随时间而改变！
Here's what I mean: when they interact with other particles,
我的意思是：当它们与其他粒子相互作用时，
like when they're produced in fusion in the sun or in radioactive decay,
比如当它们在太阳的核聚变或放射性衰变中产生时，
there are three different kinds of neutrinos,
会有三种不同的中微子，
characterized by the particles involved in their creation or annihilation.
其特征是粒子参与它们的产生或湮灭。
And when they're traveling through space,
当这些粒子穿越太空时，
there are three different kinds of neutrinos, characterized by their masses.
会有三种不同的中微子，以它们的质量为特征。
But these two sets of identities don't match up in a one-to-one correspondence;
但这两组特征并不是一一对应的；
instead, each of the "interaction" identities
相反，每一个“相互作用”特征
is actually a mix of the three "traveling" identities.
实际上都是三个“移动”特征的混合体。
And this weirdness allows neutrinos to change their identities.
这种奇怪的现象使得中微子改变了它们的特征。
That's because the traveling identities have different masses,
这是因为移动中的特征有不同的质量，
so they travel differently from each other,
所以这些粒子移动的方式不同，
technically what happens is they each pick up a complex-numbered phase
从技术上讲，它们每一个都根据
depending on their mass and how far they've traveled,
它们的质量和行进的距离来获得一个复数相位，
but I'll just show that using arrows that rotate at different speeds,
但我只会用以不同速度旋转的箭头来展示，
which is essentially the same thing.
本质上是一样的。
Anyway, because the arrows rotate at different speeds,
不管怎样，由于箭头的旋转速度不同，
over time a combination that initially looked like an electron-interacting neutrino
随着时间的推移，最初看起来像电子中微子的组合
might become the muon-interacting combination.
可能会变成μ中微子的组合。
And then, if you wait longer,
然后，如果你再等一段时间，
the combination will look like an electron-interacting neutrino again,
这个组合就会看起来像是电子中微子，
then muon-interacting, and so on, back and forth,
然后是μ中微子，如此反复，来回变换，
all happening as the neutrino flies super fast through space.
所有的一切都发生在中微子飞速穿越太空的过程中。
It's kind of like if I took my violin and played an A,
这有点像我拿着小提琴演奏A，
and somehow by the time the sound waves reached your ear,
不知何故当声波传到你的耳朵时，
the relative strengths of the frequencies had shifted.
频率的相对强度发生了变化，
so you heard the sound as an E, or a D, or an A, depending on how far away you were.
所以你听到的声音是E，D，或A，这取决于你离得有多远。
In fact, the oscillation of neutrinos back and forth between different identities was discovered in part
事实上，我们发现中微子在不同特征之间来回变换，
because we didn't see as many neutrinos coming from the sun as our understanding of fusion suggested.
部分是因为我们没有看到如我们对核聚变的理解那样的，会有很多来自太阳的中微子。
It turned out that about 2/3 of the electron-interacting neutrinos had turned into
结果发现，大约有三分之二的电中微子在通往地球的路上变为
muon and tau-interacting neutrinos en route to the earth,
μ中微子和Τ中微子。
in a very real, very long-range example of quantum superposition!
这是一个非常真实的量子叠加的例子！涉及到的距离非常远。
Oh, and one other little technicality:
哦，还有一个小的技术性问题：
even though the three "interaction"-neutrinos are named after the specific electron-family particles
尽管这三个“相互作用”中微子是以
that are involved in their creation and annihilation,
参与其产生和湮灭的特定电子家族粒子命名的，
they can still interact with (that's physics-speak for "bounce off of") other members of the electron family as well as quarks.
它们仍然可以与电子家族的其他成员以及夸克相互作用（这就是物理学所说的“反弹”）。
Ok, I'd like to thank the Heising Simons foundation for their support of this video and of neutrino research!
好的，我要感谢海辛·西蒙斯基金会对这个视频和中微子研究的支持！
They put me in touch with some of the neutrino researchers they help fund,
他们让我接触了一些他们资助的中微子研究人员，
who were awesome to talk to and learn from.
跟他们交流学习感觉非常棒。
And Heising Simons also funds a variety of research in other fields,
海辛·西蒙斯基金会还资助了其他领域的各种研究，
like exoplanets, microscale gravity, climate change, and so on.
比如系外行星、微尺度重力、气候变化等等。
To learn more about Heising Simons, check out heisingsimons.org. Thanks.
要了解Heising Simons.org的更多信息，请查看Heisingsimons.org。谢谢。
