I have a problem, there is a specific water phenomenon

我對水的一個特殊現象有疑問

that I see happening all around me

常常可以在我身邊看到

but I have no idea how it works

但我不知道水這樣運動的原理

I've been trying to figure it out for

多年來我一直想要了解為什麼

years, in fact i put a video on this

事實上在 2011 年我就把影片放在這個頻道

channel in 2011, asking people to help me

要求人們幫我想辦法！

figure it out!

00:00:16,470 --> 00:00:17,940 還有一些有趣的事情發生

there's something interesting happening

在這裡我不明白它看起來像

here I don't understand it it looks like

水滴站在水滴

water droplets are standing on water

它看起來像水排開了水

droplets. It looks like water is

它看起來也像水珠

hydrophobic it looks like when a bead of

在燒熱的鍋子上滾動

water skates across the hot griddle it

創造了一層水氣在它下面

creates a layer of water vapor underneath it

我就是不明白它是什麼

only that's not what it is

如果您有任何信息，請讓我知道

If you have any information please let me know

我會很感激

I'd appreciate it

你看過這個影片嗎？如果你看

you've seen this right? If you watch the

世界的眼睛像我一樣

world with a critical eye like I do

你會隨處可見這個現象

you'll see this everywhere for example

例如讓你自己去看看

if you've ever allowed yourself to watch

咖啡機滴漏的條件

a drip coffeemaker when the conditions

都恰到好處，你會發現，咖啡

are just right you'll notice that coffee

水珠在咖啡水面上

beads up on top of coffee

它做了什麼事情，有時當你

what does it do that sometimes when you

打開蓮蓬頭的水會

turn the shower head on the water will

灑到桶的另一面

blast to the other side of the tub

而不是使浴缸底部

instead of making the bottom of the tub

這些水珠會在

wet these pearls of water will dance on

水面上跳舞，這已經到

top of the water that's already in the

浴缸的底部。不要讓這個（顏色）困擾你

bottom of the tub. Don't let this weird you

它只是水和食用色素

out it's just water and food coloring

但有趣的是，如果你發射

but the interesting thing is if you get

水柱在恰到好處的位置

the stream in just the right location

並用在瓷器上

and interacts with a porcelain and the

水在廁所裡有恰到好處的方式

water that's in the toilet and just the

你會得到這些水珠

right fashion you'll get these little drops

我不明白什麼必要條件

that bead up. I don't understand what the

產生了這種現象

conditions required to make it happen

但我非常興奮

are, but I get really excited about it and I

我想搞清楚。

want to understand.

認真的說，有一次我們在工作的時候，阿帕奇直升機的降落墊

Seriously one time we landed an Apache helicopter on the pad

和環境控制系統

at work, and the environmental control system

曾經被漏出的冷凝水滴到柏油上

was leaking condensate down onto the

而且水珠就在那裡發生了一樣的現象

asphalt, and the beads were happening there

就在那一刻，我了解我必須

that was the moment I realized i have to

知道為什麼會這樣。

know why this is happening. In order to

為了弄清楚我們要前往科學車庫

figure it out we're going to Science Garage

拜訪我的朋友 Don Pettit

to see my friend Don Pettit who

對於這種表面化學的現象

has out-of-this-world experience in the

他有在這個世界以外的經驗

area of surface chemistry

讓我們每一天更加聰明（Smarter Every Day）。

let's go get Smarter Every Day.

這是水在水面上跳舞的現象，但我們要在地球上實現這一點

its water dancing on water, but we're gonna do it

然後再到外太空，這樣進行可以嗎？

here on earth, and then in space, that OK?

是啊，我們要先讓水珠落在這裡！

Yeah, and we're going to water down this one!

（笑）這是很糟糕。

Yeah, and we're going to water down this one! [laughs] that's bad.

如果你知道 Don Pettit 是誰，你會明白為什麼我要來找他

if you know who Don Pettit is you understand why I came to him

這是難得找到一個人

it's rare to find a person that not only

他不僅知道如何拍攝美麗的照片

understands how to capture beautiful photos

又懂

but also understands the

每個照片背後的基礎科學

fundamental science behind each image

認真來說，你還知道

seriously who else do you know that

誰會蒐集表面化學的書籍和

collects books on surface chemistry and

結合現象，你擁有這些

wedding phenomena you own these

參考？

references?

是啊。真的嗎？

Yeah. Really?

嗯，我的意思是，當你研究這種

Well I mean when you're into this kind of

東西時你需要它，對嗎？

stuff you need it, right?

不管怎麼說科學家在世界各地

Anyways scientists all over the world

在自己的實驗室創造了詳細裝置

have created elaborate setups in their

要試著去觀察這些跳舞的水滴

labs to try to observe these dancing

他們已經發現了真正厲害的資料

drops and they've got some really great

但我知道，如果我用了 Don 手中正確的攝影機

data but I knew if I got the right type

00:02:26,030 --> 00:02:27,400 只是把他轉開

of camera in Don's hands

我們不僅得到了資料

and just turned him loose

我們還會做的漂亮

we would not only get the data but

這是一個 Phantom v2511，這是一個非常非常

we would do it beautifully

快速的攝影機，而且真的很吵

it's a Phantom v2511 which is a very very

但我們從這裡打開科學

fast camera and its really loud but

並讓他一展身手

we're gonna turn on the science here

約一個小時後，

and give it a go

和 Don 一起用鏡頭和照明工作

after only about an hour of

他很快就想出了一個裝置

working through the lenses and lighting

來觀察美麗的一滴水低下

with Don, he quickly came up with a setup

登陸，彈跳，然後

to observe a beautiful single drop of

凝聚到大水池

water landing on, bouncing, and then

好吧，所以我們有一個下降的平衡

coalescing into a larger pool of water

還是表面的水，你會發現

alright so we have a drop balancing on a

它不是直接合併在一起。

still surface of water and you'll notice

合併（Coalescence ）是當你有兩個水在不同的地方

that it isn't coalescing.

碰到彼此，然後合併成為一個整體。

Coalescence is when you have two pieces of water that

現在，你會發現有一些延遲

touch and then merge to become one piece.

在合併之前，水滴會浮在水的表面

Now you notice there's this delay time

這就是所謂的“停留時間”（Residence Time）

where the drop is sitting there before

科學家們對到底發生了什麼事

coalescence that's called the 'Residence Time'

已經很了解了。

tand scientists have a pretty good

作為水滴接觸表面的科學家

understanding of what's going on here.

相信有空氣被困在中間

As a drop touches the surface scientists

當水滴停留，空氣開始

believe there's air trapped in-between

滲出的該縫隙

as the drop rests that air starts to

然後就開始合併了。

seep out of that gap and then

美國國立衛生研究院做了一個很酷的研究

coalescence occurs.

他們證實了空氣間隙理論

The National Institute of Health did this really cool

透過降低水面和水滴周圍

study where they verified the air gap theory

的空氣壓力

by reducing the air pressure

用你所期望的低氣壓

around coalescing water drops and as

降低的停留時間

you'd expect the lower the air pressure

這真的很酷

to lower the residence time which is

反正你可以清楚地看到這個影片

really cool

Don 拍攝到水滴降來

anyway you can plainly see on the video

直到座落在水面上時，他就慢慢彈上彈下

that Don captured that as the drop comes

然後它就像一個小水橋

to a rest it starts to slowly bob up and

放在氣隙中

down and then it's like a little water bridge

然後發生合併

is built in that air gap and then

這就是我看到同樣現象問的問題

coalescence occurs so this is my

我看到一個穩定狀態反彈的水滴

question in the phenomenon I'm seeing

這意味著有衝擊

I'm seeing a steady state bouncing of a

發生一遍又一遍

drop which means there's impacts

這是為什麼無法衝過

happening over and over

空氣間隙以及更容易與水結合

why is that not punching through that

為了了解這個

air gap and causing coalescence to

我們其實有看那個衝擊

happen easier? In order to understand this

這表示要拿到一個很棒的設備

we actually have to look at that impact

這是一個已經運到的設備

which means this is about to get awesome

從另一個 YouTube 頻道

this is a device that's been shipped to me

Ben 在 NightHawkInLight 頻道

from another youtube channel

他把水滴滴到喇叭上

Ben at NightHawkInLight and he has

所以我們基本上

drops of water that he puts on water

要重新做一個 Ben 做過的一樣裝置

which is sitting in a speaker so we're

來完全劇透一下，你已經在

about to basically recreate the setup

太空這樣做了，對不對？對

that Ben did. So full disclosure you've

但我們要利用這個高速攝影機

done this in space right? I have!

在地球上了解這個現象

But we're going to use this high-speed

然後你要教我關於

camera to understand the phenomenon here

你在太空中發現了什麼

on earth and then you're going to teach

對？是的，我們會由地球上開始

me about what you discovered in space

並在太空中結束

right? Yeah we're gonna, we're gonna start

[電話鈴聲]

on earth and end up in space

你好？ 嗨 Ben，我是 Destin，你好嗎？這是 Don

[phone ringing]

我們在科學車庫這裡

Hello? Hey Ben it's Destin, how are you Yeah and this is Don

真棒， Don，聽到你的聲音真酷

we're in science garage here having fun

什麼樣的頻率和幅度

Awesome, Don it's cool to hear from you

制定出最適合你？

what frequency and amplitude

制定出最適合你。 [嘟]

worked out best for you?

如果現在把這個喇叭關閉

worked out best for you. [Beep]

他們會消失嗎？來試試看吧。好的。

if we were to turn that speaker off right now they

看到了嗎？他們在那裡，但他們很快就與水凝聚了

would go away right? Well let's see. Okay

所以，好的就繼續來做但不要

See? They're there but they coalesce very quickly

改變任何東西。我們會改變一個變量

So, okay keep doing that don't

好。這是我用喇叭開啟的振動

change anything we'll change one variable

所以，我覺得這是發生的事情

OK. That's me turning on the vibration of

水正試圖在表面上停留

the speaker. So what I think is

然後往下壓迫表面

happening is; the water is trying to

嗯，沒錯。

settle and go down and press against the surface

但他因為被振動推回

Uh-huh that's right. But because it's

它增加了能量回到這個系統

being pushed back up due to that

然後將其推走

vibration it, it adds energy back into

而我想要說，這個過程保持水滴與表面

the system and then pushes it away

小小的空氣間隙，有助於維持現象

And I'm saying that that process keeps the

你可以坐在這裡假定的東西 直到你的臉是青色的，

small air gap between the drop, it helps maintain that

直到你觀察出

You can sit here and postulate things till you're blue in the face,

背後的基礎物理學是什麼

until you make an observation to see

然後你可以了解這是怎麼回事

what that fundamental physics is, then

然後這跟高速有什麼關係

you can back out what's going on and

水滴會做很多事情來幫助回答這些問題

high-speed of what's going on with that

這是迅速成為

drop it would do a lot to help answer these questions

最真棒裝置之一

this is quickly becoming

我一直參與其中的一部分，你同意嗎？

one of the most awesome setups I've ever

是啊，這真是超讚。

been a part of, would y'agree?

但是，你去過太空！

Yeah this is just totally awesome.

好吧，我們在這裡

But you've been to space!

經過多年等待一個真相

Allright, here we are

我們終於有了一切

the moment of truth after years of waiting

我們需要來更真實的觀察

we finally have everything we

開始了。

need in order to make

它就在那裡

an actual observation. Here we go.

你看見了嗎？當我第一次看到這個現象

and there it is

它就在我面前像個大大的讚

did you see it? When i first saw this

不像我預料的水滴溶解

footage it stood out to me like a sore

它幾乎像

thumb instead of crashing into the drop

這些波峰和波谷像是一些

like I anticipated it's almost like

移動的捕手嘗試

those peaks and valleys make some type

捕捉水滴，輕輕地讓它下來

of moving catcher's mitt that gently

而且不會破壞該空氣層

catches the drop and lets it down gently

現在我想放大，看看我們能

without breaking that air layer

看到這個波可否捕獲水滴

now i want to zoom in and see if we can

它就在那裡，很明顯發生了什麼事情

see that wave catch the drop

想想這樣子的話

there it is it's pretty clear what's

有人把水球扔向你

going on here think about it this way if

你抬起手來想盡量快速跟他對撞

somebody threw you a water balloon would

然後風險是會衝破他的

you rush your hand up and try to meet it

表面張力？不，你會嘗試

really quickly and risk bursting that

把手盡量依照水球的速度

surface tension? No, you would try to

所以你可以降低

match the velocity of the balloon with

碰撞動能

your hands so you could decrease the

事實上有一個公式

collisional kinetic energy in fact

來計算碰撞動能，這就是

there's an equation for how to calculate

那些讓水滴能夠存在的因素

collisional kinetic energy and that's

如果液體

what factors into whether or not the

和小水滴有同樣的速度

drop survives if the velocity of the

那因素會變成0

liquid and the small drop are about the

碰撞動能迅速

same then that factor goes to 0 and the

降低到0。現在我們明白

collisional kinetic energy quickly

我們可以推斷，時間是一個巨大的

decreases to zero now that we understand

此因素，可能有一堆

this we can infer that timing is a huge

的下降，他們不會浮著，因為

factor here and there's probably a bunch

他們打錯波了

of drops that just don't survive because

事實上，這正是我們在高速攝影機看到的

they hit the wave wrong

還有一件事

in fact that's exactly what we see in

想想還有引力

the high-speed. One more thing to think

不斷把水滴拉回讓他掉下

about is the fact that gravity is

到振動表面，這意味著它

constantly pulling the drops back down

總是得找軟著陸點來

to that vibrating surface which means it

在水面降下

always has to find the soft spot to land

更大的引力就會強至他融入水中。

the larger the drop, the greater the

但是，如果你做這個實驗在

gravitational force pushing down on it.

沒有重力的地方呢？

But what if you did this somewhere where

哦，那就會反彈

there was no weight on the drop?

我有影片。我們可以看看它？

Oh, then it bounces off

當然！

I've got the video. Can we see it?

我發現了這個現象

Yeah!

就在阿拉巴馬州在2011年天然的樹林中

I discovered this phenomenon for myself

也是同一年

occurring naturally in the woods of

Don Pettit 前往國際太空站

alabama in 2011, the same year that

在那裡他意外了

Don Pettit launched to the international

重建的現象

space station where he accidentally

用非常驚人的方式。

recreated the phenomenon in a really

他進行了類似喇叭水面的實驗

remarkable way. He performed a very

不同的地方是這次是在無重力的水球中

similar water speaker experiment, except

為了讓事情更有趣，Don 把

in weightlessness the water forms a

一個空氣氣泡放到水球中

sphere. Just to make it interesting Don

然後他開始從喇叭中播放音頻

put an air bubble on the inside of that

為了要看看會發生什麼

water sphere and then he played tones

00:08:33,140 --> 00:08:37,250 [Don] ...和水球氣泡附著在圓錐喇叭

through the speaker just to see what

我目前播放是60赫茲

would happen

我要開始增加的頻率，要開始了

[Don]... and the air bubble is attached to the speaker cone, and so is

哇，所以我們會在氣泡與水的表面得到了一連串的

the water and i'm at 60 Hertz i'm going

駐波上的節點，

to start increasing the amplitude, here we go

接著，

Wow. So we're getting a series of

我要來放一個方型波

standing nodes on the interface of the

OK ...試試三角波

air bubble with the water. I'm going to

所以 Don 打了不同的頻率，幅度，

put a square wave in

他播放了不同類型的音樂，像是搖滾樂

OK... triangle wave

然後他播了大提琴

So Don played with different frequencies, amplitudes,

Don 說，每當他播放大提琴

he played different types of music like rock

水滴就會從水球中的

and roll, and then he played the cello

表面彈出

Don said whenever he played cello music specifically,

並開始在裡面四處彈跳

little drops would break off

大提琴！？

on the inside of the sphere

有一些關於大提琴！