液氮冻结你的皮肤需要多快？：英语精读讲义

If we dumped a puddle of liquid nitrogen straight into the palm of our hand,

如果我们把一滩液氮直接倒进手心，

how long do you think it would take for the skin to cool down enough 語法

你认为皮肤需要多久才会降温到

to where the nitrogen could latch on and bite it? 習語

能让液氮附着并咬上一口的程度？

Now, in previous videos,

在之前的视频中，

I've showed you that you can take liquid nitrogen and splash it in your face

我向大家展示过，你可以把液氮泼到脸上，

or roll it off your hands with little to no effect. 短語搭配

或者让它从手上滚落，几乎不会有任何影响。

And that's because the Leidenfrost effect basically vaporizes the nitrogen into a gas, 文化背景

这是因为莱顿弗罗斯特效应基本上把液氮蒸发成了气体，

which shields you from the intense cold of this liquid.

在你和这种液体的极度严寒之间形成了一层保护罩。

But what do you think would happen

但你觉得会发生什么，

if we left the nitrogen in one place for a little bit too long?

如果我们让液氮在一个地方停留的时间稍微长一点？

For example, what if we poured this into our hands

例如，如果我们把它倒在手上，

and just let it sit?

就任由它留在那儿？

Now, if we were to take a little bit of this liquid 語法

现在，如果我们取一点这种液体，

and just pour it in the palm of our hand,

直接倒在手心里，

but we keep our hand moving fast enough,

只要我们的手保持足够快的移动，

you can see the liquid doesn't actually do any damage.

你可以看到这液体实际上并没有造成任何伤害。

It just skittles around kind of like playing a game of air hockey 用詞

它只是像玩空气曲棍球一样在上面滑来滑去，

until the nitrogen completely evaporates.

直到液氮完全蒸发。

But what would happen if we stopped moving our hand

但如果我们停止移动手，

and let the liquid nitrogen settle down 短語動詞

让液氮稳定下来，

and stay in one place for a little bit longer?

并在一个地方停留稍微长一点，会发生什么呢？

Okay, so this is where I start getting a little bit more nervous. 表達脈絡

好了，现在我开始有点紧张了。

I don't want to stop moving my hand

我不想停下我的手，

because I know what's going to happen.

因为我知道会发生什么。

But watch this.

但看好了。

If I do stop for a second, watch right there.

如果我确实停顿一秒钟，看这里。

You can see it actually instantly frostbites the skin.

你可以看到它瞬间就把皮肤冻伤了。

Let's do that again with a little bit more liquid.

我们用多一点液体再试一次。

That's quite a bit.

这挺多的了。

I'm just going to

我只是要

Whoa!

哇哦！

You can see immediately it starts frostbiting me.

你马上就能看到它开始冻伤我了。

And, uh, as it warms up,

然后，呃，随着它变暖，

it disappears as quickly as it came. 語法

它消失得和来时一样快。

Now, to me this feels like a little bit of a bee sting.

现在，对我来说，这感觉就像有点被蜜蜂蛰了。

Almost like I got stung,

几乎就像我被蛰了一下，

and the pain lingers for about 10 to 20 seconds.

疼痛持续了大约10到20秒。

You can see the skin is turning a little bit red there.

你可以看到那里的皮肤变红了一点。

It's not to the point of where it'll be a first degree burn just yet.

还没到一度烧伤的程度。

But it would be if we left it exposed a little bit longer.

但如果我们让它暴露的时间再长一点，就会的。

Let's try a smaller bead here.

让我们在这里试一小滴。

Let that settle down.

让它稳定下来。

Boom!

砰！

Ooh!

噢！

Okay, I chickened out. 短語動詞

好了，我退缩了。

I don't really want to keep this going much longer.

我真的不想让这持续太久。

I'm going to try one little bead

我打算试一小滴，

and see if I can make it all the way through. 習語

看看我能不能坚持到底。

This may not be the smartest idea,

这可能不是最聪明的想法，

but I'm doing this for you.

但我是为了你们才这么做的。

There we go.

好了。

There's a nice little bead.

这是一颗漂亮的小液滴。

We'll let it settle down and

我们让它稳定下来，然后

Oh, man, that kind of actually hurt. 語氣意圖

哎呀，天哪，这还真有点疼。

So, you can see it's turned my skin completely white.

所以，你可以看到它把我的皮肤变得完全苍白。

As it warms back up, though,

不过，随着它恢复温暖，

it starts to fade.

它开始消退。

You can see this is taking about 10 to 15 seconds.

你可以看到这大概需要10到15秒。

Now, I do feel a little bit of pain there.

现在，我确实感觉到那里有点疼。

It is a lingering sensation

这是一种挥之不去的感觉，

that feels like after you got stung by a bee.

就像被蜜蜂蛰了之后的感觉。

And you can see the coloration in the hand is a little bit more red.

而且你可以看到手上的颜色变得更红了一点。

But even at this point,

但即使到了这一步，

I wouldn't consider that a first degree burn.

我也不认为那是一度烧伤。

It might be an extreme case of frostnip, 用詞

这可能是极度表皮冻伤，

but I wouldn't expect that to blister up. 短語動詞

但我估计它不会起水泡。

You can see it only takes a fraction of a second 短語搭配

你可以看到，液氮只需要几分之一秒的时间

for nitrogen to actually grab onto your skin and start burning it.

就能抓住你的皮肤并开始灼伤它。

And the reason I say burn is because frostbite is actually very similar 語法

我之所以说是灼伤，是因为冻伤实际上非常类似于

to first, second, and third degree burns, 文化背景

一度、二度甚至三度烧伤，

depending on how long you're exposed.

取决于你暴露的时间长短。

I wanted to show you this reaction

我想向你们展示这种反应，

because I've done a lot of experiments with liquid nitrogen,

是因为我做过很多液氮实验，

and I didn't want you to get the impression 短語搭配

我不想让你们产生一种印象，

that it was super safe stuff to play with.

认为这是非常安全的可以随便玩的东西。

You can see that it will burn you,

你可以看到它会灼伤你，

and it'll burn you very quickly.

而且烧伤的速度非常快。

And it does hurt.

它确实很疼。

It leaves a mark.

会留下印记。

And you might be wondering what this feels like,

你们可能会好奇这是什么感觉，

and right now I have lingering sensations all over my hands

现在我整个手上都有那种挥之不去的感觉，

as if I was stung by bees multiple times. 語法

就像被蜜蜂蛰了很多次一样。

There is a lingering pain in that part of my hand,

我手上的那个部位有种隐隐作痛的感觉，

almost like somebody's taking a nail and pressing it down into my skin.

简直就像有人拿着钉子往下按我的皮肤。

I get an itchy, tingling sensation that makes me want to scratch it. 用詞

我有一种发痒、刺痛的感觉，让我很想去挠它。

So, if you do happen to get frostbitten, 語法

所以，如果你碰巧被冻伤了，

this is the way that you want to treat it.

这是你应该采取的治疗方法。

Get yourself a bowl of lukewarm water. 用詞

给自己弄一碗温水。

You do not want it to be hot,

你不能用热水，

and you don't want it to be cold.

也不能用冷水。

Just lukewarm or room temperature,

只要温水或室温的水，

and just soak the area for a couple of minutes 短語搭配

只要把患处浸泡几分钟，

until it starts to feel better.

直到它开始感觉好些。

Then take a warm, dry cloth

然后拿一块温暖干燥的布，

and press it to the affected area

压在患处，

and just hold it

只要按住它，

until it starts to warm back up.

直到它开始重新变暖。

Now, depending on the severity, 短語搭配

现在，根据严重程度，

you might want to go seek medical attention 短語搭配

你可能需要去就医，

and see what your doctor has to say.

看看医生怎么说。

So, how long does it take for liquid nitrogen to freeze your skin?

那么，液氮冻伤你的皮肤需要多长时间呢？

Well, according to my experiments, 短語搭配

嗯，根据我的实验，

it only takes a fraction of a second.

只需要几分之一秒。

If you leave your skin exposed any longer than that,

如果你让皮肤暴露的时间超过那个时间，

it's going to start freezing the muscles,

它就会开始冻结肌肉，

freezing the tendons,

冻结肌腱，

and you could actually get to the point 短語搭配

而且你实际上可能会达到

where you freeze your entire hand solid. 語法

把你整只手完全冻成冰块的程度。

And that would not be a very good day. 習語

那可就真是倒大霉了。

That's all I got for this experiment.

这就是我这个实验的全部内容了。

I'll see you in the next video.

下期视频见。

Talk to you then.

到时聊。