令人驚嘆的蜂蜜盤繞高速影片！- 每天聰明一點點 53：英語精讀講義

Hey, it's me, Destin.

嘿，是我，Destin。

Welcome to Smarter Every Day.

歡迎收看Smarter Every Day。

And today we're going to show you some pretty cool high speed

今天我們要向你們展示一些非常酷的高速畫面，

and it has nothing to do with all those assault rifles. 片語搭配

這和那些突擊步槍沒有任何關係。

It's actually much sweeter than that, 慣用語

其實它比那要甜得多，

literally.

字面意義上的甜。

Check this out. 片語動詞

看看這個。

It is a jar of honey.

這一罐是蜂蜜。

So,

那麼，

I know this sounds a little strange, 表達脈絡

我知道這聽起來有點奇怪，

but we've got a high speed camera set up 片語動詞

但我們架設了一台高速攝影機，

and we are going to show you something called the liquid rope coil effect. 用詞

我們要向你展示一種叫做「液體繩捲繞效應」的現象。

This is how it works.

它是這樣運作的。

You just put some of the honey on this chopstick here

你只要把一些蜂蜜挑在這根筷子上，

and just drip it down

然後讓它滴下來，

and look at this.

看看這個。

Check out that.

仔細看看。

How cool is that? 語氣意圖

這有多酷？

It has to do with the viscosity of the fluid

這與流體的黏度有關，

and basically the liquid is piling up. 片語動詞

簡單來說就是液體在不斷堆積。

So, I think this is really really neat.

所以，我覺得這真的非常非常巧妙。

So, we're going to get a little bit of high speed of it

接下來我們要用高速攝影機拍一下，

and then after that

然後在那之後，

we're going to discuss this

我們將討論這個現象，

in uh more detail.

了解它的更多細節。

Fluid dynamics are awesome.

流體力學太棒了。

It's tempting to think that this would be an easy math problem, 表達脈絡

人們很容易認為這是一個簡單的數學問題，

but it turns out people have been studying this for 50 years. 文法

但事實上，人們已經對此研究了50年。

To explain, 表達脈絡

為了解釋清楚，

let me show you the variables.

讓我給你看看這些變數。

This section is called the coil

這一部份叫做捲繞區，

and this section is called the tail.

這一部份叫做尾部區。

The coil and the tail together make up the total height h. 片語動詞

捲繞區和尾部區加起來就是總高度 h。

The mass flow rate of the material is q 用詞

物質的質量流量是 q，

and the initial radius at the top of the tail is called a sub zero.

尾部頂端的初始半徑被稱為 a0。

We'll call the radius at the bottom a sub one

我們把底部的半徑稱為 a1，

and the exciting part is the angular coiling frequency,

最令人興奮的部份是角捲繞頻率，

which is omega.

也就是 omega。

The fluid itself also has internal properties that we have to consider.

流體本身也有我們必須考慮的內部特性。

Density is rho

密度是 rho，

and the surface tension coefficient is gamma.

表面張力係數是 gamma。

The kinematic viscosity is nu.

運動黏度是 nu。

Okay,

好了，

simply put viscosity is the measure of the thickness of a fluid. 表達脈絡

簡而言之，黏度是衡量流體濃稠度的指標。

Viscosity is the measure of a fluid to resist a shear or tensile stress.

黏度是流體抵抗剪切或拉伸應力的量度。

Dynamic viscosity is measured in poise,

動力黏度的單位是泊（poise），

whereas kinematic viscosity is measured in stokes. 文法

而運動黏度的單位是斯托克斯（stokes）。

Kinematic viscosity is also referred to as the diffusivity of momentum 片語搭配

運動黏度也被稱為動量擴散率，

and that makes sense if you think about it,

仔細想一下，這是有道理的，

to diffuse momentum throughout a fluid.

也就是將動量擴散到整個流體中。

As you can see here,

正如你在這裡看到的，

obviously the molasses honey mixture is the most viscous.

顯然糖蜜和蜂蜜的混合物是最黏稠的。

Okay,

好了，

if these big words are boring you,

如果這些生僻字眼讓你覺得無聊，

just wait.

稍等一下。

There's a shower scene for you.

馬上就有一場沐浴戲要上演了。

But if you're like me and you want to understand what's going on 片語動詞

但如果你和我一樣，想要理解發生了什麼，

and you want to know the math,

並且想了解其中的數學原理，

let's do this.

那我們開始吧。

What you're looking at here are the four different types of flow

你現在看到的是四種不同類型的流動狀態，

that scientists can describe using the variables that we defined earlier.

科學家可以用我們剛才定義的變數來描述它們。

Let's start here with this one.

我們從這個開始。

This is the viscous flow regime.

這是黏性流動狀態。

The way it works is as h or the height that the fluid is dropped from is relatively small,

它的原理是，當 h（流體滴落的高度）相對較小時，

the flow has to naturally go into a spiral

液流必然會自然形成螺旋狀，

because the fluid has to get out of the way of itself. 慣用語

因為流體必須給自己讓路。

Now,

那麼，

the interesting thing about the equation used to define the coiling frequency 文法

用來定義捲繞頻率的方程式中，有趣的地方在於，

is that it doesn't even include the kinematic viscosity of the fluid.

它甚至沒有包含流體的運動黏度。

That's interesting seeing how it's called the viscous flow regime. 文法

這很有趣，畢竟它被稱為黏性流動狀態。

Okay,

好了，

the second condition we're talking about here is called the gravitational flow regime.

我們要討論的第二種情況叫做重力流動狀態。

Basically,

基本上，

the way it works is as that height increases,

它的原理是，隨著高度增加，

gravity begins to take over and stretch the fluid. 片語動詞

重力開始佔據主導並拉伸流體。

So,

所以，

basically the viscosity of the fluid is resisting that stretching

基本上，流體的黏度在抵抗這種拉伸，

and that's why the equation there shows that kinematic viscosity starts to come into play. 慣用語

這就是為什麼那裡的方程式顯示，運動黏度開始起作用。

That's where the coiling becomes uniform and stable.

在這個狀態下，捲繞變得均勻且穩定。

That's the exact condition that we were filming with the high speed camera earlier.

這正是我們早些時候用高速攝影機拍攝時的條件。

The third condition we're going to talk about is called the inertial regime.

我們要討論的第三種情況叫做慣性狀態。

Now,

那麼，

as height gets very very long,

當高度變得非常非常高時，

what happens is that fluid becomes very fast and very very skinny.

發生的情況是，流體變得非常快且非常非常細。

Now,

現在，

you notice in the equation that the radius of the coil at the bottom

你會注意到在方程式中，底部捲繞的半徑

is factored into the denominator and raised to the 10th power. 用詞

被放入分母中，並提高到 10 次方。

Now,

那麼，

if you think about it,

如果你仔細想想，

that means the smaller the radius gets, 文法

這意味著半徑越小，

the higher the coiling frequency,

捲繞頻率越高，

which makes sense.

這很有道理。

Okay,

好了，

the fourth regime is why I love science.

第四種狀態是我熱愛科學的原因。

All we know is that somewhere between the gravitational regime and the inertial regime, 文法

我們只知道，在重力狀態和慣性狀態之間的某個地方，

everything goes out the window. 慣用語

一切常規都不適用了。

All of a sudden you'll go from a steady state coil 片語搭配

突然之間，你會從穩定的捲繞狀態

to some erratic figure eight pattern or something stranger.

變成不規則的 8 字形，或者更奇怪的形狀。

But if you raise it just a little bit more,

但如果你再稍微提高一點高度，

all of a sudden you're steady state again.

突然之間，它又恢復穩定狀態了。

Even more and you're back unstable.

再高一點，它又變得不穩定了。

Everything is erratic.

一切都變得不規則。

The frequency is varying wildly,

頻率變化劇烈，

but it seems to have some sort of pattern, 片語搭配

但似乎又存在某種規律，

but we don't know why.

只是我們不知道為什麼。

It's very interesting and there's been a very complex study done on it

這非常有趣，已經有一項非常複雜的研究針對它進行了探討，

and I'll leave a link in the description to that

我會在資訊欄裡留下連結，

so you can check it out yourself.

以便你可以自己去看看。

I think it's amazing that we as humans can conquer so many things about the world around us,

我覺得很神奇，作為人類我們可以征服周圍世界的這麼多事物，

but we still struggle with the smallest of things.

但我們仍然在最微小的事情上掙扎。

If you're interested in knowing why I did this video, 文法

如果你有興趣知道我為什麼做這部影片，

I'll leave that info in the description as well.

我也會把那部份資訊留在資訊欄裡。

Boy,

天哪，

that got weird in a hurry, 慣用語

畫風怎麼一下子變奇怪了，

didn't it? 文法

是吧？

Every single day you can check out the liquid rope coil effect in your own shower.

每一天你都可以在自己的淋浴間裡觀察到液體繩捲繞效應。

It's pretty easy.

這很簡單。

Just take your shampoo,

只需拿你的洗髮精，

which is a pretty viscous fluid,

那是一種相當黏稠的流體，

and throttle the flow rate and the height 用詞

控制流量和高度，

until you get the right combination

直到你找到正確的組合，

and then boom,

然後砰的一聲，

you lock in on the liquid rope coil effect. 片語動詞

你就鎖定了液體繩捲繞效應。

It's pretty cool.

這非常酷。

You can change things and see how the variables affect its action.

你可以改變條件，看看這些變數如何影響它的行為。

Anyway,

不管怎樣，

I'm not responsible for any extra shampoo you end up using. 片語動詞

我可不對你多用的洗髮精負責。

I'm Destin.

我是 Destin。

You're getting smarter every day.

你每天都在變得更聰明。

Have a good one. 語氣意圖

祝你愉快。