Why is ketchup so hard to pour? - George Zaidan

為甚麼番茄醬這麼難擠？－喬治塞登

譯者: Thunder Song 審譯者: XiuDe Huang

French fries are delicious.

薯條是美味的。

French fries with ketchup are a little slice of heaven.

加上番茄醬的薯條 感覺就像天堂一樣。

The problem is it's basically impossible

問題是基本上不可能

to pour the exactly right amount.

擠出確切數量的番茄醬。

We're so used to pouring ketchup that we don't realize

我們習慣去使用番茄醬，

how weird its behavior is.

但是我們並沒有意識到 這是一個奇怪的現象。

Imagine a ketchup bottle filled with a straight up solid like steel.

想像裝滿了像鐵一樣固體的 番茄醬的瓶子。

No amount of shaking would ever get the steel out.

即使再大的晃動 也不能把鐵倒出來。

Now imagine that same bottle full of a liquid like water.

現在想像瓶子裏裝滿了水。

That would pour like a dream.

便能輕易地倒出來。

Ketchup, though, can't seem to make up its mind.

儘管番茄醬自己 好像還沒下定決心，

Is it is a solid? Or a liquid?

它是固體？或者說是液體？

The answer is, it depends.

答案是，它取決于其他因素。

The world's most common fluids like water, oils and alcohols

世界上最常見的流質 像是水、油以及酒精

respond to force linearly.

對力大小的比例是成線性關係，

If you push on them twice as hard, they move twice as fast.

如果你用兩倍的力去擠壓， 便會以兩倍地速度被擠出來。

Sir Isaac Newton, of apple fame, first proposed this relationship,

艾薩克·牛頓爵士，因蘋果而出名的那個， 首次提出這種關係，

and so those fluids are called Newtonian fluids.

所以這些液體也稱之為牛頓流體。

Ketchup, though, is part of a merry band of linear rule breakers

儘管番茄醬是一部分 打破這個線性規律定理的液體，

called Non-Newtonian fluids.

稱之為非牛頓流體。

Mayonnaise, toothpaste, blood, paint, peanut butter

蛋黃醬、牙膏、血液、油彩、花生醬

and lots of other fluids respond to force non-linearly.

以及其它一些液體 對力大小都是非線性地。

That is, their apparent thickness changes

這就是說，表面厚度的改變

depending on how hard you push, or how long, or how fast.

取決于你擠壓時候用的力的 大小、時間長短，或者多快。

And ketchup is actually Non-Newtonian in two different ways.

番茄醬從兩個角度 表現出非牛頓流體。

Way number one: the harder you push, the thinner ketchup seems to get.

第一種：你用勁越大， 擠出來的似乎越少。

Below a certain pushing force,

在一個確定的力大小之下，

ketchup basically behaves like a solid.

番茄醬的特性就像鐵一樣。

But once you pass that breaking point,

但是如果你超過了那個臨界點，

it switches gears and becomes a thousand times thinner than it was before.

它的流體特性大概會 比以前明顯一千倍。

Sound familiar right?

是不是有種熟悉的感覺？

Way number two: if you push with a force below the threshold force

第二種：如果你使用臨界值之下的力，

eventually, the ketchup will start to flow.

最後，番茄醬的量便會開始下降。

In this case, time, not force, is the key to releasing ketchup

這種情況下，時間，而不是力， 才是番茄醬的決定因素，

from its glassy prison.

從這個光滑的容器中擠出。

Alright, so, why does ketchup act all weird?

好吧，為甚麼番茄醬的行為是如此奇怪？

Well, it's made from tomatoes, pulverized, smashed, thrashed,

用番茄碾碎，搗爛，捶打 而做出的番茄醬，

utterly destroyed tomatoes.

完全摧毀了番茄本來的樣子。

See these tiny particles?

看到這些小東西了沒？

This is what remains of tomatoes cells

這個番茄遺的細胞

after they go through the ketchup treatment.

經過了一系列處理之後。

And the liquid around those particles?

這些小東西周圍的液體是什麼？

That's mostly water and some vinegar, sugar, and spices.

大部份都是水以及一些醋、糖和香料。

When ketchup is just sitting around,

當番茄醬放在一邊的時候，

the tomato particles are evenly and randomly distributed.

這些番茄地小分子是平等地，被隨機打亂了。

Now, let's say you apply a weak force very quickly.

現在，我們快速地用一個很小的力。

The particles bump into each other,

這些微粒相互碰撞，

but can't get out of each other's way,

但並無法擺脫其他，

so the ketchup doesn't flow.

所以番茄醬無法像液體一樣流動。

Now, let's say you apply a strong force very quickly.

現在，讓我們快速地用一個極大的力，

That extra force is enough to squish the tomato particles,

這樣的一個力足夠擠壓這些番茄微粒，

so maybe instead of little spheres,

所以可能就不再是小球，

they get smushed into little ellipses, and boom!

它們被搗成小橢圓，然後嘣！

Now you have enough space for one group of particles

現在你有足夠的空間讓一小群微粒

to get passed others and the ketchup flows.

穿過然後讓番茄醬流出。

Now let's say you apply a very weak force but for a very long time.

現在讓我們用一個很小的力 但是作用很長的一個時間。

Turns out, we're not exactly sure what happens in this scenario.

然後你會發現， 我們並不確定這裡發生了什麼。

One possibility is that the tomato particles near the walls of the container

一種可能性是靠近杯壁的番茄微粒

slowly get bumped towards the middle,

慢慢地被擠到了中間，

leaving the soup they were dissolved in,

離開它們之前 溶解於其中的溶液，

which remember is basically water,

而那個溶液 基本上就是水，

near the edges.

在邊緣地方的水。

That water serves as a lubricant betwen the glass bottle

水作為玻璃瓶 以及番茄醬中間的

and the center plug of ketchup,

一種潤滑劑，

and so the ketchup flows.

然後番茄醬便可以流出來。

Another possibility is that the particles slowly rearrange themselves

另一種可能是這些分子慢慢的重組

into lots of small groups, which then flow past each other.

變成許多小組，接著它們便可以流出來。

Scientists who study fluid flows are still actively researching

研究流體的科學家仍然在研究

how ketchup and its merry friends work.

番茄醬和其它的果醬朋友 是如何工作的。

Ketchup basically gets thinner the harder you push,

基本上番茄醬會隨著你力的變大而液化，

but other substances, like oobleck or some natural peanut butters,

但是其它一些物質， 比如玉米糊或者一些天然花生醬

actually get thicker the harder you push.

事實上會隨著力的變大 而變得更偏向固態性質。

Others can climb up rotating rods,

其它還有一些會爬上旋轉的攪拌棒，

or continue to pour themselves out of a beeker,

或者它們自己就能持續從燒杯中倒出，

once you get them started.

一旦你開始這麼做。

From a physics perspective, though,

儘管從物理學角度上來說，

ketchup is one of the more complicated mixtures out there.

番茄醬是一種更加複雜的混合物。

And as if that weren't enough, the balance of ingredients

如果這還不夠，原料的平衡

and the presence of natural thickeners like xanthan gum,

比如還有天然增稠劑黃原膠的存在，

which is also found in many fruit drinks and milkshakes,

它也存在於其它水果飲料以及奶昔，

can mean that two different ketchups

會意味著兩種不同的番茄醬

can behave completely differently.

會表現出完全不同的行為。

But most will show two telltale properties:

但是絕大多數會有兩種性質：

sudden thinning at a threshold force,

當力量達到臨界值，醬會液化，

and more gradual thinning after a small force

以及當你長時間施加一個很小的力

is applied for a long time.

它也會有逐漸液化的傾向。

And that means you could get ketchup out of the bottle in two ways:

這意味著你可以 用兩種方法擠出番茄醬：

either give it a series of long, slow languid shakes

一種是持續地，緩慢地極小的晃動

making sure you don't ever stop applying force,

並且保證你一直用力按壓，

or you could hit the bottle once very, very hard.

或是你可以給瓶子施加 一個非常非常大的力。

What the real pros do is keep the lid on,

真正專業的做法就是蓋上瓶蓋，

give the bottle a few short, sharp shakes

給瓶子一些短的，急速的晃動

to wake up all those tomato particles,

來喚醒這樣的一些番茄微粒，

and then take the lid off

然後打開蓋子，

and do a nice controlled pour onto their heavenly fries.

然後很好地控制倒在那些美味地薯條上。