The science of macaroni salad: What's in a mixture? - Josh Kurz

通心粉沙拉的科学：什么是混合？ - Josh Kurz

Transcriber: Andrea McDonough Reviewer: Jessica Ruby

翻译人员: Gabriella Hu 校对人员: Zongzhen Yang

The world we live in is made of things,

我们生活的世界是由事物组成的

billions and billions of different things,

无数个不同的物体，

like pickles and pianos and dump trucks and octopi.

比如咸菜，

和钢琴，

还有自卸车

和章鱼

尽管这些物体看上去完全不同，

And even though these things seem totally different,

they're all made of the same stuff, just combined in different ways.

它们都是由同样的东西做成的，

只是以不同的方式组成的

To give you an idea of how this combining works,

想要了解这个组合的过程，

let's take something apart.

我们先把东西拆开

Let's start with this bowl of macaroni salad.

我们就从这碗通心粉色拉开始吧

If you were to reverse a recipe for macaroni salad,

如果你想颠倒一个通心粉色拉的食谱，

你们可以看到它是由混合

you'll see it's made by mixing together a bunch of ingredients,

一堆食材制成的

比如通心粉，

like macaroni, mayo, vinegar, vegetables, and mustard.

蛋黄酱，

醋，

蔬菜，

和芥末

This type of combining is called a mixture.

这种组合叫做混合

当你做一个混合物的时候，

When you make a mixture,

你在把两个或更多的东西结合在一起

you're combining two or more things together

而没有改变

without actually changing the chemical identity of those things.

这些东西的化学性质

Like mud, for example.

拿泥举例吧，

The soil and water in mud haven't actually changed.

泥里面的土和水实际上没有改变

They're still soil and water,

它们依旧是土和水

你只是创造了土和水的混合物：

you've just created a mixture of soil and water -- mud.

泥

It turns out that macaroni salad is actually a mixture of mixtures

其实，通心粉色拉是

混合物的混合物

because many of the ingredients, like mayo and mustard,

因为使用的许多食材，

比如蛋黄酱和芥末，

本身已经是混合物了

are already mixtures themselves,

which is nice for us because if we look closely,

这对我们来说很好

因为如果我们仔细地观察，

我们会看到三种不同形式的混合物

we'll the see the three main types of mixtures that exist.

The size of the particles in a mixture determines the type of mixture.

混合物中颗粒的大小

决定混合物的类型

On one end of the scale is a suspension, like our muddy water example.

在第一个级别是悬浮液体，

比如说浑水，

You get this if you take big chunks of something

你把一大块东西和

and mix it with something else so those chunks are just floating around.

别的东西混在一起

这些块状体到处浮动

拿芥末来说吧，

Take runny mustard for example.

You'll see a bunch of little particles

你们能看到许多小颗粒

like mustard seeds, pepper, allspice, and minced shallots

比如芥菜籽，

胡椒，

香料，

和剁碎的青葱

all floating around in a liquid,

都在一种液体中漂浮，

in this case vinegar with water.

在芥末中，液体是醋和水

This is called a suspension

这个叫做悬浮液体

because you've got particles of one thing suspended in another.

因为是一种物体的颗粒

浮在另一个物体中

Now, on the other end of the spectrum is a solution.

另一系列的液体

叫做溶液

这个混合物中的颗粒太小，

The particles in this mixture are so small,

它们是分子了

they are the actual molecules.

A solution is sort of like a suspension of molecules

溶液有点像悬浮的分子

里面一种分子混合

where one type of molecule is blended or dissolved with another.

或溶解在另一个物体中

Vinegar is an example of a solution

醋是溶液的一个例子

里面的醋酸分子

where the molecules of acetic acid are blended with molecules of water.

混合在水分子里

The chemical properties of the molecules haven't changed,

分子的化学性质没有改变

它们只是均匀地混合在一起

they're just evenly mixed together now.

盐水和碳酸苏打

Saltwater and carbonated soda are both examples of solutions

都是一种溶液

都是一种分子溶解在水中

where other molecules are dissolved in water.

The last type of mixture is called a colloid,

最后一种混合物叫做胶体，

which is somewhere between a suspension and a solution.

介于悬浮液体和溶液之间

It's when you take two materials that don't dissolve

当你把两个不相容的物体放在一起

使它们颗粒变得特别小

and you make the particles so small that they can't separate.

以至于它们无法分开

Mayo is what happens when you take oil and water,

蛋黄酱就是把

油和水，

which don't mix,

虽然不相溶，

但是把它们结合在一起，

and you bind them together,

通常靠另一种物体

usually with the help of another substance called an emulsifier.

叫做乳化剂

In the case of mayo, it's lecithin, found in eggs.

在蛋黄酱中，蛋黄中的卵磷脂就是乳化剂

现在，你只能发现特别小粒的油

And now you are left with really small globs of oil

hanging out with really small droplets of water.

和小水珠悬挂在一起

Whipped cream, hairspray, Styrofoam, and Jello

奶油，

发胶，

发泡胶，

和果冻

are all other examples of colloids.

都是一种胶体

我们再次回到通心粉色拉

So, let's get back to macaroni salad.

You've call colloids like mayo, suspensions like mustard,

我们有胶体，比如蛋黄酱，

像芥末的悬浮液体，

and solutions like vinegar,

还有溶液，醋

但是我们也有芹菜，

but you've also got celery, shallots, and all other vegetable chunks

青葱，

还有其它的块状蔬菜

that are also part of the salad.

它们也是色拉的一部分

These aren't mixtures, really, but we can break them up,

它们其实不是混合物，

但是我们可以把它们分解

就像电视机可以被分解成

just like a TV can be broken up

into smaller and smaller complex component parts.

更小，更复杂的零部件

拿蔬菜来讲，

In the case of vegetables, if you keep breaking things up,

如果我们一直把它们分解下去，

它们终究会变成成千上万个

they'll eventually end with thousands of complex organic molecules,

复杂的有机分子，

things like ATP synthase

比如三磷酸腺苷合酶

and RNA transcriptase

和逆转录酶

and water.

还有水

现在，我们已经拆散了所有的溶液，

So now, once we've unblended all the solutions,

unmixed all the colloids, separated all the suspensions

分解了所有的胶体，

分开了所有的悬浮液体

剖解了所有的蔬菜，

and taken apart all of our vegetables,

从物理的角度，我们分解了所有的东西

we've reached the end of what we can unmix physically.

What we're left with is a whole bunch of molecules,

只剩下一大堆分子，

and these molecules remain chemically the same

这些分子的化学性质依旧保持不变

不管是单独的

whether they are by themselves or thrown together in a salad.

还是一起放到色拉里

如果你想继续分解下去，

If you want to separate these guys even further,

we need to unmix things chemically,

我们需要从化学角度分解，

也就是说我们需要拆散一些化学键

which means we need to start breaking some bonds.