In our water cycle workshop we talk about 'Supercooled Water'

在今天的水循環工坊，我們要討論的是 「超冷卻水」

I've got a demo here for you that's great to try at home.

我會做個示範，你也可以在家試試看

So, you may notice on those cold winter evenings people place salt

在冬天晚上，你或許看過有人把鹽巴

out on the streets and pavements, because salty water can go well below zero degrees

撒在街上或人行道，這樣做是因為鹽水在攝氏零下

and remain liquid it freezes.

仍然不會結冰

We're going to try and get a bottle of fresh water to get well below zero degrees C

我們也來試試看，讓一瓶水在攝氏零度以下

but still remain a liquid.

仍然處在液體狀態

For your super cooled water demo

超冷卻水的實驗

you need lots and lots of crushed ice,

你需要很多很多的碎冰和

a small bottle of water

一小瓶水

a beaker with round about 100ml of tapwater

一個燒杯，裡面裝100毫升的自來水

plenty of table salt,

大量的食鹽

teaspoon, and a metal cylinder to place all of your ingredients inside.

茶匙、還有用來裝所有東西的鋼瓶

First thing I'm going to do is to pour plenty of crushed ice

現在我要把大量的碎冰

into the bottom of my metal cylinder then

倒進鋼瓶底部，然後

I need five teaspoons salt to sprinkle around

再把五茶匙的鹽撒在上面

I'm going to now place my small water bottle inside

現在我把這瓶水放進去

Around that water bottle now i need to pack in

在這瓶水的周圍，盡可能地

as much ice as possible.

把大量的碎冰塞進去

Now, another 5 spoons of salt

現在，再放五茶匙的鹽巴

Next, i'm going to take 100ml of water

再來，準備好100毫升的水

and add 5 teaspoons of salt to this

把五茶匙的鹽巴加進去

Stir the mixture around

攪一攪

Now i'm going to pour this salty water all around the ice

現在我把鹽水倒進碎冰的周圍

around my bottle

還有水瓶周圍

Now, if you've got any room

如果空間還夠

add some more ice on top

再放些碎冰在頂部

What we do now is just sit and wait for a good 30 minutes

大約靜置個30分鐘

and then our supercooled water should be ready

我們的超級冷卻水就完成了

The reason why i can get a bottle of fresh water below zero degrees without freezing

這瓶純水在攝氏零下不會結冰的原因

is because in our bottled water,

是因為瓶裝水裡面

we have nonucleation points. A nucleation point is simply

沒有凝結核；凝結核就是

any impurities inside that bottle of water which is going to allow

在瓶裝水裡頭的雜質

ice crystals to form around it. Now when I have my bottle of fresh water that is

這些雜質會讓冰晶形成在周圍。當我把零度以下的純水

liquid but below zero degrees, if i cause a disturbance

给它一些干擾因子

like pouring that water over an ice cube, I'm going to create many nucleation sites

例如: 把它倒在冰塊上，那麼就會有需多的凝結核

and that liquid will turn to ice instantly.

如此一來，零度以下的純水就會瞬間結冰

it's been about 30 minutes now, so let's see if our super cooled water

30分鐘到了，讓我們用我們的超冷卻水

is ready to make some instant ice

來做超急凍的冰塊

So there you go. Instant ice, fantastic experiment.

你看到了嗎?急凍冰塊馬上就出來了，超完美的實驗

Why don't you try at home?

在家你也來試試看!