French fries with ketchup are a little slice of heaven.

薯條搭上番茄醬根本人間天堂。

The problem is it's basically impossible to pour exactly the right amount.

問題是要倒出正確的量根本是件不可能的事情。

We're so used to pouring ketchup that we don't realize how weird its behavior is.

我們習慣於倒出番茄醬而不了解這奇怪的現象為何。

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

想像一瓶番茄醬住滿了像鋼一般的固體。

No amount of shaking would ever get the steel out.

沒有任何搖晃可以使鋼露出來。

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

現在再想像一下，一個同樣的瓶子裝滿了像水一般的液體。

That pour like a dream.

倒起來順極了。

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

番茄醬，看起來不能夠彌補這個洞。

Is it a solid? Or liquid?

這是固體呢？還是液體？

The answer is, it depends.

答案是：不一定。

The world's most common fluids like water, oils and alcohols respond to force linearly.

世上最常見的液體，例如：水、油和酒精，對應了線性力量。

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

若你以兩倍的力氣推動，他們則會以兩倍的速度移動。

Sir Isaac Newton--of apple fame--first proposed this relationship, and so those fluids are called Newtonian fluids.

牛頓先生，以蘋果為名，第一次提出這項關係，所以這些流體被稱為牛頓流體。

Ketchup, though, is part of a merry band of linear rule breakers called "non-Newtonian fluids."

番茄醬，是一個打破線性規則的特例，被稱為非牛頓流體。

Mayonnaise, toothpaste, blood, paint, peanut butter and lots of other fluids respond to force non-linearly.

美乃滋、牙膏、血液、油漆、花生醬，還有其他很多的流體都適用於非線性力量。

That is, their apparent thickness changes depending on how hard you push, or how long, or how fast.

也就是說，它們的外觀時常會有變化，完全依照你推得多大力、推的時間有多長或是推得多快而決定。

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

而番茄醬可由兩個方式看出它是非牛頓流體。

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

第一種方式為：你推得越用力，番茄醬就會流的越薄。

Below a certain pushing force, ketchup basically behaves like a solid.

以下面特定的推動力道，番茄醬基本上像固體一般。

But once you pass that breaking point, it switches gears and becomes a thousand times thinner than it was before.

但一旦你突破了這個突破點，它將會變換而變得比先前的還要薄上好幾千倍。

Sound familiar right?

聽起來很熟悉對吧？

Way number two: If you push with a force below the threshold force eventually, the ketchup will start to flow.

第二種方式：如果你以低於起初的力量推動，最終，番茄醬將會開始流動。

In this case, time, not force, is the key to releasing ketchup from its glassy prison.

在這個情況下，時間，而非力量，是將番茄醬從它的玻璃狀監獄釋放的關鍵。

Alright, so, why does ketchup act all weird?

所以，為什麼番茄醬的流動會如此的怪異呢？

Well, it's made from tomatoes, pulverized, smashed, thrashed, utterly destroyed tomatoes.

番茄醬是由番茄製成的；壓碎、打碎，完全的將番茄破壞。

See these tiny particles?

看到這些微小的粒子了嗎？

This is what remains of tomatoes cells after they go through the ketchup treatment.

這是經過製做成番茄醬的步驟後的番茄細胞。

And the liquid around those particles?

那麼這些粒子附近的液體是？

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

那些大部分是水，還有些許的醋、糖和香料。

When ketchup is just sitting around, the tomato particles are evenly and randomly distributed.

當番茄醬只是穩穩地坐於一處時，番茄的粒子會平坦的、隨機的分布。

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

現在，來談談如果給予一個非常微小但快速的衝擊。

The particles bump into each other, but can't get out of each other's way, so the ketchup doesn't flow.

粒子們會彼此碰撞，但不會離開彼此應走的道路，所以番茄醬並不會流動。

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

現在，再來說說如果你給予一個很強大又快速的力道。

That extra force is enough to squish the tomato particles, so maybe instead of little spheres, they get smushed into little ellipses, and boom!

多增加的力道足夠使番茄醬的粒子移動，所以或許不再只有小小的範圍，它們被撞擊成小小的橢圓形，然後… 蹦！

Now you have enough space for one group of particles to get passed others and the ketchup flows.

現在你有足夠的空間給予一團的粒子，通過和使番茄醬流動。

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

現在來談談你施以一個非常微小但持續很久的力。

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

結果，我們不能夠確定在這個情況下究竟會發生什麼事。

One possibility is that the tomato particles near the walls of the container slowly get bumped towards the middle, slowly get bumped towards the middle, leaving the soup they were dissolved in, which remember is basically water, near the edges.

一個可能為：靠近容器壁的番茄粒子慢慢的彼此碰撞到了中間，留下會將它們溶解的湯，而基本上是留在靠近邊緣的水。

That water serves as a lubricant between the glass bottle and the center plug of ketchup, and so the ketchup flows.

水就如同玻璃瓶和番茄醬中的潤滑劑，所以番茄醬會流動。

Another possibility is that the particles slowly rearrange themselves into lots of small groups, which then flow past each other.

另一個可能性為：粒子們自己重整成許多小團體，接著再利用彼此流動。

Scientists who study fluid flows are still actively researching how ketchup and its merry friends work.

研究流體流動的科學家仍然很積極的做研究，想知道番茄醬和它的好朋友們是如何運作的。

Ketchup basically gets thinner the harder you push, but other substances, like oobleck or some natural peanut butters, actually get thicker the harder you push.

番茄醬基本上是你推得越用力，它就會變得越薄，但其他的物質，像歐不裂和一些自然的花生醬是你推得越用力它會變得越厚。

Others can climb up rotating rods, or continue to pour themselves out of a beaker, once you get them started.

其他的可以附著於轉動的棍子上或是持續地流出燒杯，只要你開啟了它們的第一步。

From a physics perspective, though, ketchup is one of the more complicated mixtures out there.

從物理學的角度來看，番茄醬是一個很複雜的混合物。

And as if that weren't enough, the balance of ingredients and the presence of natural thickeners like xanthan gum, which is also found in many fruit drinks and milkshakes, can mean that two different ketchups can behave completely differently.

就如同不夠一般，材料的均勻和像黃原膠這種自然的濃縮劑，也在許多水果飲料和奶昔中被發現，以此可知，兩種不同的番茄醬可以完全不同的樣態。

But most will show two tell-tale properties: Sudden thinning at a threshold force, and more gradual thinning after a small force is applied for a long time.

但大多都會有兩個特性：在一開頭倒出時會突然的變薄，然後在長時間施以小小的力道後會漸漸的變薄。

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

這代表你可以以下面兩種方式使番茄醬倒出瓶子：

Either give it a series of long, slow languid shakes making sure you don't ever stop applying force, or you could hit the bottle once very, very hard.

不是給它一連串的長時間的、慢慢搖晃的確定你不會停止的力道，就是重重的拍擊一下它的瓶子底部。

What the real pros do is keep the lid on, give the bottle a few short, sharp shakes to wake up all those tomato particles, and then take the lid off and do a nice controlled pour onto their heavenly fries.

有真正實質幫助的幫法為：讓蓋子蓋上在將瓶子強烈的搖動來喚醒那些番茄粒子，再將蓋子打開，完美的控制好，將它倒於薯條上。