What is chemical equilibrium? - George Zaidan and Charles Morton

翻译人员: Huiying Ma 校对人员: Eugenie Yu

Say two people are walking down the street,

当两个人走在街上

and they bump into each other.

不小心撞到一起

They'll just shake it off and walk on.

他们会立马分开，然后继续前行

Sometimes that happens with molecules too.

这种情况有时也发生在分子身上

They just bounce off each other, and that's that.

不过它们只是互相弹开而已

But what if two people were to bump into each other,

但是如果两个人撞到一起

and during that collision,

在这个过程中

one person's arm got severed

其中一个人的手断了

and reattached to the other person's face?

粘到了另一个人的脸上，情况会如何呢？

Now that sounds really weird,

这听起来很奇怪

but it's similar to one of the many ways

但这与分子间发生反应众多方式之一

that molecules can react with each other.

非常相似

Two molecules can join and become one.

两个分子可以结合，变成一个

One can split apart and become two.

一个分子也可以分裂成两个

Molecules can switch parts.

分子可以相互交换部件

All these changes are chemical reactions,

所有这些变化都是化学反应

and we can see them happening around us.

它们就发生在我们身边

For example, when fireworks explode,

例如燃放烟花

or iron rusts,

铁生锈

or milk goes bad,

牛奶变质

or people are born,

人的出生

grow old,

变老

die,

and then decompose.

死亡

最后分解

But chemical reactions don't just happen willy nilly!

但是化学反应不会平白无故的发生

Everything has to be right.

所有条件都要具备

First, the molecules have to hit each other

首先，分子要以正确的方式互相碰撞

in the right orientation.

And second, they have to hit each other hard enough,

其次，他们得相撞必须足够强

in other words, with enough energy.

换言之，就是有足够的能量

Now you're probably thinking

现在你可能会想

that a reaction just happens in one direction and that's it.

化学反应只沿着一个方向发生

Sometimes that's true.

有时这是正确的

For example, things can't unburn

比如东西不能逆燃烧

or unexplode.

或是逆爆炸

But most reactions can happen in both directions,

但大部分的化学反应可以沿着两个方向发生

forward and reverse.

或正或逆

There's no reason that our face-arm guy

脸上有手臂的男孩

can't bump into armless girl,

也不是不可能会再次撞到无臂女孩

reattaching that arm back to its original socket.

从而把手臂接回原来的位置

Now let's zoom out a bit.

现在，让我们拉远一下镜头

Now let's say that you've got

假设现在有

a thousand people on the street,

一千人走在街上

and all of them start with their limbs

开始他们的四肢

normally attached.

都在正常的位置上

At the beginning, every collision is a chance

刚开始，他们每一次相撞，

for Person A to transfer an arm to Person B's face.

路人甲的手臂都有机会黏在路人乙的脸上

And so at the beginning,

more and more people end up

所以一开始，

with arms attached to their faces or arms missing.

会有越来越多人的手黏到别人的脸上或是失去了自己的手

But as the number of people with arm-faces

随着这些人数的增加

and missing arms grows,

collisions between those people become more likely.

他们相撞的可能性也就随之增加

And when they bump into each other,

那么当他们相撞

guess what?

猜猜会发生什么事？

Normal-appendage people are reproduced.

他们又变回了四肢完好的正常人

Now the number of limb transfers per second forward

这样说来，每秒肢体脱节的数目

will start high and then fall,

从刚开始很多，逐渐减少

and the number of limb transfers per second backward

同时每秒肢体回到原位的数目

will start at zero and then rise.

会由零开始逐渐上升

Eventually they'll meet,

最后他们会不断趋近

they'll be the same.

数目相同

And when that happens,

the number of people in each state stops changing,

当这个发生的时候

每种形态的人的数目将停止改变

even though people are still bumping into each other

尽管他们仍在互相碰撞

and exchanging limbs.

并交换肢体

Now how many people do you think

现在你觉得，每种形态的人数会有多少呢？

there are in each state?

Half and half, right?

一半一半对吧？

No, well, maybe.

不，嗯。。。也可能吧

It depends.

这要依情况而定

It could be 50/50,

这可能是一半一半

but it could be 60/40

也可能是60/40

or 15/85,

又或者15/85

or anything.

或是任何比例

We chemists have to get our little, gloved hands dirty

我们化学家必须亲自动手，弄脏带的手套

- ah, well, we're in a lab so not really dirty -

哈哈，恩，我们的实验室并没有那么脏的

to figure out what the actual distribution

去找出实际的分子比例

of molecules is.

Even though each of limb transfers

即使每一次肢体交换

is a pretty dramatic event for the people involved,

对参与者来说 是非常神奇的事情

if we zoom out,

如果我们将镜头拉远

we see population numbers that don't change.

我们会发现人群数目不会发生改变

We call this nirvana equilibrium,

我们将这种重生称之为平衡

and it doesn't just happen with chemical reactions.

它不仅存在于化学反应中

Things like gene pools

其他比如基因库

and highway traffic show the same pattern.

以及高速公路也有这种现象

It looks pretty still from 30,000 feet,

从高空三万英尺看下去好似静止

but there is lots of crazy stuff

但其实有很多疯狂的东西

happening on the ground,

在地面发生

you just need to zoom in to see it.

你只需将镜头拉近即可发现