It can strike without warning, at any moment.
任何时候，毫无预警地，你就会被电到。
You may be walking across a soft carpet and reaching for the door knob when suddenly...zap!
你可能正走过一个软软的地毯，刚要伸手摸门把手，然后突然...啪！
To understand static electricity, we first need to know a bit about the nature of matter.
为了理解静电，我们首先需要理解物质的一些性质。
All matter is made up of atoms that consist of three types of smaller particles:
所有物质都是由原子组成的，原子又是由三种更小的粒子组成的：
negatively charged electrons, positively charged protons, and neutral neutrons.
带负电的电子，带正电的质子，以及中性的中子。
Normally, the electrons and protons in an atom balance out,
一般来说，一个原子中的电子数和质子数相平衡，
which is why most matter you come across is electrically neutral.
这就是为什么大部分你接触过的物质都是电中性的。
But electrons are tiny and almost insignificant in mass,
但是电子很小，质量几乎可以忽略，
and rubbing or friction can give loosely bound electrons enough energy
摩擦能使受到束缚较小的电子得到足够的能量，
to leave their atoms and attach to others, migrating between different surfaces.
从而离开从属的原子，转移到其他原子上，在不同物体表面迁移。
When this happens, the first object is left with more protons than electrons and becomes positively charged,
此时，第一个物体剩下的电子就比质子少了，从而变成了带正电；
while the one with more electrons accumulates a negative charge.
相对应地，拥有更多电子的物体就积累成了带负电。
This situation is called a charge imbalance, or net charge separation.
这种情况称为电荷失衡，或者净电荷分离。
But nature tends towards balance, so when one of these newly charged bodies comes into contact with another material,
但是大自然趋向于平衡，所以当一个新产生的带电物体接触到另一个物质，
the mobile electrons will take the first chance they get to go where they're most needed,
这些游离的电子就会立即跑到最需要它们的地方，
either jumping off the negatively charged object,
不是从带负电的物体上瞬间溜走，
or jumping onto the positively charged one in an attempt to restore the neutral charge equilibrium.
就是一拥而上到带正电的物体上，试图恢复电中性的平衡状态。
And this quick movement of electrons, called static discharge, is what we recognize as that sudden spark.
这种电子的快速移动被称为静电放电，这就是我们感受到的突然的触电。
This process doesn't happen with just any objects.
并不是任何物体都会静电放电。

Otherwise you'd be getting zapped all the time.
否则你会经常被电到。
Conductors like metals and salt water tend to have loosely bound outer electrons, which can easily flow between molecules.
像金属和盐水一样的导体往往带有受到束缚较弱的外层电子，这些电子能够轻易在分子间流动。
On the other hand, insulators like plastics, rubber and glass
另一方面，像塑料、橡皮和玻璃一样的绝缘体，
have tightly bound electrons that won't readily jump to other atoms.
它们具有紧密结合的电子，所以不容易跑到其他原子上。
Static build-up is most likely to occur when one of the materials involved is an insulator.
静电积聚最容易发生在其中一种物质是绝缘体的情况下。
When you walk across a rug, electrons from your body will rub off onto it,
当你走过一个地毯，你体内的电子就会通过摩擦转移到地毯上，
while the rug's insulating wool will resist losing its own electrons.
然而，绝缘的毛地毯不会失去自己的电子。
Although your body and the rug together are still electrically neutral,
尽管你的身体和地毯的总和是电中性的，
there is now a charge polarization between the two.
现在却在两者之间产生了电荷的极化。
And when you reach to touch the door knob, zap!
然后当你要摸门把手的时候，啪！
The metal door knob's loosely bound electrons hop to your hand to replace the electrons your body has lost.
金属门把上受束缚较弱的电子涌到你的手上，来填补你体内丢失的电子。
When it happens in your bedroom, it's a minor nuisance.
当静电放电发生在你的卧室，这还是小问题。
But in the great outdoors, static electricity can be a terrifying, destructive force of nature.
但是在广阔的室外，静电可以变成大自然可怕的、具有破坏性的力量。
In certain conditions, charge separation will occur in clouds.
在某种条件下，电荷分离会发生在云层里。
We don't know exactly how this happens.
我们不知道具体这是如何发生的。
It may have to do with the circulation of water droplets and ice particles within them.
这可能和水滴的循环移动以及它们中的冰粒子有关。
Regardless, the charge imbalance is neutralized by being released towards another body,
不管怎样，电荷失衡会通过对另一个物体放电从而达到中和，
such as a building, the Earth, or another cloud in a giant spark that we know as lightning.
比如通过一个建筑，通过地球，或者另一个云，此时产生的巨大的电火花就是我们熟知的闪电。
And just as your fingers can be zapped over and over in the same spot,
就像你的手指的同一个地方可以一次又一次被电到，
you better believe that lightning can strike the same place more than once.
你最好相信闪电也可以在同一个地方闪好多次。