(单词翻译:单击)
The world can be a minefield in the winter,
冬季到来，世界变为了一个布雷区，
when just about anything metal can zap you with a painful electric shock.
任何金属物品都会使你触电。
Shocks happen for the same reason balloons stick to the ceiling after you rub them on your hair,
触电的原因和用气球摩擦你的头发后，气球会吸附在天花板上的原理一样，
which is also what causes lightning: the triboelectric effect.
闪电同理，这些都是由于：摩擦起电效应。
People have experimented with it for thousands of years,
千年以来，人们做过无数实验，
and we’ve come up with some pretty good ways of mitigating the shocks
而我们也有了一些缓解触电的好方法
so you don’t have to be afraid of doorknobs all the time.
因此，你不用总是害怕门把手了。
But despite millennia of experiments,
但除了几千年的实验，
there are still some things about this everyday phenomenon that we don’t quite understand.
对于这个日常现象，我们仍有许多不了解的地方。
The triboelectric effect happens when rubbing two electrically neutral things together builds a static charge on them,
当带中性电的物品相互摩擦时，彼此会产生静电荷，
so one becomes positively charged and the other becomes negatively charged.
其中一个带正电，另一个带负电，摩擦起电效应就由此产生。
Our oldest records of it come from Ancient Greek philosophers, who knew that after you rubbed amber against fur,
有关摩擦起电效应最古老的记载来自古希腊哲学家，他们发现用琥珀摩擦皮毛后，
it would start attracting feathers and hair.
就能吸附羽毛和头发。
People have been playing with the triboelectric effect ever since, making huge tables of which materials build charge the best.
自那时起，人们就一直在运用摩擦起电效应，利用带电荷量最大的材料制作巨大的桌子。
Mostly, they’re electrical insulators, because that lets the charges build up in one place.
这些桌子多半是电绝缘体，因为这种方式是将电荷聚集在了一个地方。
In a conductor, they’d spread out.
在一个导体中，电荷会相互分散。
The moving charges themselves can be negatively charged electrons,
移动的电荷本身可以是带负电荷的电子，
or they can be ions — whole atoms with an electric charge.
他们也可以是离子——整个原子只带有一种电荷。
It just depends on what kinds of materials are involved and how they’re rubbed together.
这取决于使用的是什么材料以及是如何一起摩擦的。
Even though I’ll be talking in terms of electrons moving for the rest of the video,
虽然在接下来的视频中，我打算讲讲电子运动，
everything works pretty much exactly the same if it’s ions moving around instead.
但是如果是离子在移动，那么每一步都基本相同。
So here’s how you get zapped: Some things, like polyester and rubber, are good at holding onto extra electrons.
你之所以会被电到是因为：一些物品，如聚酯和橡胶，都擅长抓住额外电子。
Others, like wool, are good at giving electrons away.
其他如羊毛类的物品，均擅长释放电子。
When you shuffle your feet on the carpet, you rub an electron-receiver against an electron-giver,
当你的脚步在地毯上移动，这就相当于你用一个电子接收器摩擦电子释放器，
so you get negatively charged shoes and a positively charged carpet.
因此，你的鞋子就会带有负电，而地毯则带正电。
Those extra electrons move up from your shoes onto your skin, since humans are good electrical conductors.
多余的电子会从你的鞋游走到你的皮肤上，而人类是很好的导电体。
But metals are even better conductors, so the electrons jump toward a doorknob when you go to grab it.
但是金属确是更好的导电体，所以当你抓住门把手时，电子会迅速的跳到门把手上。
When that happens, a tiny lightning bolt goes between your hand and the doorknob.
这个过程中，一个微小的闪电球会存在于你的手和门把手之间。
The moving electrons heat the air between your hand and the knob, and you feel that heat as the pain of an electric shock.
移动中的电子会加热你手掌和把手之间的空气，而你感受到的热量就像触电一样疼。
Shocks tend to be more of a problem in the winter than the summer, because the cold air can’t hold as much water as warm air.
在冬天这种情况会比在夏天更加严重，因为寒冷空气无法像温暖空气那样锁住水分。
When it’s warm, the extra water in the air makes the air more conductive.
天气温暖时，空气中额外的水分使空气变得更加传导。
So on a humid day, any charge you build up leaks off into the wet air before you touch metal.
因此，天气潮湿时，你身上的任何电荷都会在你碰到金属前泄漏到潮湿的空气之中。
But even in the winter, there are things you can do to avoid getting shocked.
但即使在冬天，也有避免触电的方法。
Wearing clothes that build up more charge leads to worse sparks, and so does lots of rubbing or shuffling as you walk.
穿着能产生不放电电荷的衣服，还有当你走路时，不要摩擦地面或是拖着脚步走。
Switch to full, wide steps and wear lots of cotton, which hardly builds charge at all, and the shocks won’t be as bad.
大步走，穿着棉含量高的衣服，这样的衣服几乎不产生电荷，就算触电也没那么疼。
You might get some weird looks waddling around like that, but hey, at least it’ll hurt less.
或许这样的穿着和走路方式会很奇怪，但至少没那么疼了呀。
You can also try touching things with something metal first, like a key, so electrons jump from there,
你也可以先摸摸带金属物的东西，比如钥匙，这样电子就会跳到到钥匙上，
and the key gets hit with the burst of hot air instead of your hand.
钥匙就会代替你的手来承受热气的爆发。
But even though we mostly know how to stop the triboelectric effect from zapping you,
虽然我们基本了解如何避免因摩擦起电效应而受伤，
there's a lot we still don't know about why it happens in the first place.
但是我们仍然不清楚为什么会出现这种现象。
For one thing, electrons repel each other, so any extras on one surface should make it harder to pile more on there.
电子相互排斥，表面上的任何额外电子应该会使电子的聚集变得更加困难。
But the electrons build up anyway.
但电子还是聚集起来了。
This problem took scientists decades to solve, and they're still working out some of the finer details.
这个问题困扰了科学家几十年，如今仍在专注其中的一些细节。
It turns out that the electrons don't just hop between surfaces as they rub together — they jump because of friction.
人们发现，摩擦时电子并不仅在表面之间跳跃——电子因摩擦力而跳跃。
A lot of the time, friction comes from chemical bonds that quickly form and break as two surfaces slide past each other.
很多时候，摩擦力都来自化学键，当两个表面相互来回滑动时，化学键能快速形成并打破。
And chemical bonds often involve unequally shared electrons, where electrons spend more time on one side of the bond than the other.
化学键通常包含不相等的共价电子，电子在键结的一边所花时间比另一边更长。
Those sides are more likely to have an extra electron or two when the bond breaks, so they become the electron-receivers.
当键结打破，时间长的那一边可能会有一个或两个额外电子，所以它们就变成了电子接收器。
But since the electrons tend to stay with their molecules,
但是由于电子更倾向于和它们的分子待在一起，
they don't really keep other electrons from getting caught by nearby molecules, and the charge builds up.
它们不会真的阻止其他电子被附近原子所吸收，因此，电荷就产生了。
We also don't fully understand how the triboelectric effect works in thunderstorms.
我们还是无法完全了解，在暴雨天气，摩擦起电效应是如何进行的。
We know the bottoms of thunderclouds tend to get negatively charged as ice crystals and dust rub against each other, but we're not sure why.
我们知道，当冰晶和灰尘相互碰撞时，雷云底部容易形成负电荷，但是我们并不确定为什么会这样。
It's possible that denser ice crystals tend to get more negatively charged,
可能是由于密集的冰晶容易吸收更多负电荷，
so the negative charge follows them down as they sink to the base of the cloud.
所以当它们沉入云层中时，负电荷也会跟着下来。
Another option is that crystals charge differently depending on the temperature,
也有可能是因为晶体可以根据温度产生不同电荷，
and the temperatures in different parts of a cloud lead to negative charge on the bottom.
在云层不同部位的温度导致了云层底部带负电荷。
Then there are the convection currents in the clouds,
云层中有对流，
which might affect the process as they mix the different kinds of crystals and other particles together.
当它们将不同晶体和其他粒子一起混合时，对流可能对混合的过程产生影响。
All of these ideas probably play a role,
所有这些想法都有可能，
but we don't really know if one is more important than the others.
但是我们并不清楚哪一个是占决定作用的。
Plus, sometimes positive charge accumulates on the bottom of clouds, which is even harder to explain.
另外，有些时候，正电荷在云层底部相聚集，这一点甚至更难以解释。
And it's tough to study any of this directly, since flying planes in storm clouds is … not very safe.
要直接研究任何一点都非常困难，因为在暴风云中飞行十分不安全。
We're stuck with mostly small-scale experiments that involve crashing ice crystals and water droplets together in labs.
我们的实验室正主要忙于涉及碎冰晶和水滴的小规模研究。
So, we know that you get static shocks because of the triboelectric effect,
因此，我们知道你受到静电的冲击是由于摩擦起电效应，
and we know that static shocks are just miniature lightning bolts.
而且我们知道静电是微小的闪电球。
But somewhere between shuffling feet on the carpet and rubbing ice crystals in clouds, the physics gets a little more mysterious.
但是介于地毯上摩擦步伐和云层中摩擦冰晶之间的问题，让物理学变得更加神秘。
Thanks for watching this episode of SciShow!
谢谢收看这一期的科学秀！
If you're interested in learning more about how we figured out electricity,
如果你对我们是如何探究电流感兴趣，
you can check out our episode about Benjamin Franklin, Founding Nerd — including what really happened with that kite and key.
请收看我们的视频《Benjamin Franklin,Founding Nerd》——视频中还讲到了那只风筝和钥匙到底经历了什么鬼。
