How can something that is frozen keep you warm?

冰凍的東西怎麼能取暖？

But countless animals burrow into the snow to keep warm.

但無數動物都鑽進雪地裡取暖。

And Inuits have been making igloos for centuries.

幾個世紀以來，因紐特人一直在製作冰屋。

The question is, how can frozen water actually keep you warm?

問題是，冰凍的水究竟如何取暖？

OK, full disclosure, I've never actually built a igloo before, and from everything that I'm reading online, they actually seem pretty difficult to build.

好吧，坦白說，我以前從沒真正建過冰屋，而且從我在網上讀到的所有資訊來看，冰屋似乎很難建造。

So what I'm building right now is actually a quinzee, which is slightly different.

是以，我現在正在建造的實際上是一個昆蟲，這兩者略有不同。

A true igloo is made by stacking snow blocks that are cut from the existing snow pack.

真正的冰屋是從現有雪堆上切割下來的雪塊堆疊而成。

The blocks are stacked in an upward spiral, forming the walls of an igloo.

積木呈螺旋狀向上堆疊，形成冰屋的牆壁。

The key to the whole structure.

整個結構的關鍵。

A quinzee is more like a snow cave, but instead of digging into the existing snow pack, snow is piled up and packed down before digging it out.

昆茲更像是一個雪洞，但不是挖現有的雪堆，而是先把雪堆起來，然後再挖出來。

And both keep you warm using the same thermodynamic principles.

兩者都利用相同的熱力學原理為你保暖。

But to understand that, we first need to understand that cold doesn't really exist.

但要理解這一點，我們首先需要理解寒冷其實並不存在。

Everything, regardless of how solid it feels, is actually comprised of billions of tiny particles that can move around and jiggle with energy.

萬事萬物，無論感覺有多堅固，實際上都是由數十億微小的粒子組成的，這些粒子可以四處移動，並隨著能量而抖動。

That jiggling is what we feel as heat.

這種抖動就是我們感覺到的熱量。

The faster particles jiggle, the hotter it feels.

顆粒抖動得越快，感覺就越熱。

And the slower particles jiggle, the colder it feels, all the way down until particles stop moving altogether, which is called absolute zero.

粒子抖動得越慢，感覺就越冷，一直到粒子完全停止運動，這就是所謂的絕對零度。

Your body produces heat by turning calories into energy.

人體通過將熱量轉化為能量來產生熱量。

And when you feel cold, it's because heat is leaving your body faster than your body can produce it.

當你感到寒冷時，是因為熱量離開身體的速度快於身體產生熱量的速度。

Heat is transferred in three different ways.

熱量有三種不同的傳遞方式。

Radiation, convection and conduction, all of which are happening inside an igloo.

輻射、對流和傳導，所有這些都在冰屋裡發生。

Heat radiates off your body, moves around inside the igloo through convection and eventually is lost to the walls with conduction.

熱量從身體散發出來，通過對流在冰屋裡移動，最後通過傳導流失到牆壁上。

To prevent heat from leaving, you need a way to stop or slow down the transmission of heat.

要防止熱量散失，就必須設法阻止或減緩熱量的傳播。

And typically we do this with some type of insulation, either down or synthetic, that works by trapping millions of tiny little air pockets.

一般來說，我們使用某種類型的保溫材料（羽絨或合成材料）來實現這一目的，這種材料的作用是捕捉數以百萬計的微小氣孔。

But how do air pockets keep heat from leaving?

但是，氣穴是如何阻止熱量散失的呢？

Well, it all comes back to that jiggling.

這一切都要歸功於抖動。

In solid objects, when one or two particles are heated and start to jiggle, they bump into the others, transferring their energy and moving heat through an object.

在固體物體中，當一個或兩個粒子受熱並開始抖動時，它們就會撞擊其他粒子，從而傳遞能量並使熱量在物體中流動。

This is called conduction.

這就是所謂的傳導。

But air is different.

但空氣不同。

Air particles are spaced farther apart.

空氣微粒之間的距離更遠。

And so when those particles jiggle, they don't influence the particles around them as easily.

是以，當這些粒子抖動時，它們不會輕易影響周圍的粒子。

Instead, heat moves through air by convection.

相反，熱量是通過對流在空氣中移動的。

Warm air molecules are less dense.

暖空氣分子的密度較低。

And so they float upward until they cool off, causing them to sink.

是以，它們會向上漂浮，直到冷卻下來，導致它們下沉。

So if you want to prevent heat from moving through air, all you have to do is stop air from moving.

是以，如果你想阻止熱量通過空氣流動，你所要做的就是阻止空氣流動。

And that's why even though its particles aren't moving very fast, snow is still a really good insulator because snow is comprised of almost 95% air, air that is trapped so it can't go anywhere.

這就是為什麼即使雪的顆粒移動速度並不快，雪仍然是非常好的絕緣體，因為雪幾乎由 95% 的空氣組成，空氣被困在雪中，哪裡也去不了。

And it's physically separating the snow particles so it can't conduct very well.

而且，雪粒會被物理分離，是以傳導性很差。

If you've ever tried to melt snow for drinking water, you've probably encountered this.

如果你曾嘗試融雪取水，你可能會遇到這種情況。

If you just throw a chunk of snow in a hot pot, it's not going to melt.

如果你把一大塊雪扔進熱鍋裡，它是不會融化的。

Or at least it's going to take a really long time and use a ton of fuel.

或者至少需要很長時間，耗費大量燃料。

That's because only the snow that is in direct contact with the heat is going to melt.

這是因為只有與熱量直接接觸的雪才會融化。

The rest is insulated from the heat by itself.

其餘部分則自行隔熱。

But if we add just a little bit of water to see the melting process, you'll notice it goes a whole lot faster.

但是，如果我們只加一點點水來觀察熔化過程，你會發現它的速度會快很多。

And this huge chunk of snow only makes a small amount of water.

而這一大塊雪只能製造少量的水。

That's because this huge chunk of snow is mostly air.

這是因為這一大塊雪主要是空氣。

Now, an igloo is never going to be as warm as a well insulated house, but temperatures inside an igloo can be as much as 40 to 60 degrees warmer than the outside air.

現在，冰屋永遠不會像隔熱性能良好的房屋那樣溫暖，但冰屋內的溫度可能比室外空氣溫度高出 40 到 60 度。

OK, it is about 37 inside, which may not seem all that warm until you see my Bluetooth thermometer outside, which is reading about 12 degrees.

好吧，室內溫度約為 37 度，看起來並不暖和，直到你看到我室外的藍牙溫度計，它的讀數約為 12 度。

That is a difference of about 25 degrees.

兩者相差約 25 度。

That could mean the difference between freezing to death and surviving.

這可能意味著凍死和活下來的區別。

If the temperature outside was even colder, like it is in the Arctic Circle, where Inuits first invented the igloo, the temperature difference would be even greater.

如果室外溫度更低，就像因紐特人最早發明冰屋的北極圈那樣，溫差就會更大。

But that's just one thermodynamic principle.

但這只是熱力學原理之一。

Remember how we said that hot air rises?

還記得我們說過熱空氣會上升嗎？

The way igloos are designed take advantage of this, too.

冰屋的設計也利用了這一點。

Traditional igloos have a raised platform for sleeping to take advantage of the warm rising air, while the door is set lower to trap any cold air that might make its way inside.

傳統的冰屋有一個高出地面的睡覺平臺，以利用上升的暖空氣，而門則設置得較低，以阻擋可能進入室內的冷空氣。

All of this is designed to trap heat and prevent it from escaping.

所有這些都是為了截留熱量，防止熱量外洩。

But where does the heat come from?

但熱量從何而來？

Well, as I mentioned earlier, your body is constantly radiating heat, which after a while will raise the temperature inside the igloo.

正如我前面提到的，你的身體會不斷散發熱量，一段時間後，冰屋裡的溫度就會升高。

The more people you bring in an igloo, the warmer it will be.

帶進冰屋的人越多，冰屋就越暖和。

Or you can even bring something as small as this lantern, which is enough to help bring up the temperature inside the igloo.

您甚至可以帶一盞像這樣的小燈籠，它足以幫助提高冰屋內的溫度。

It may never feel hot, but compared to the temperatures outside, it's much, much warmer.

也許永遠不會覺得熱，但與室外的溫度相比，這裡要暖和得多。

I hope you enjoyed this video.

希望你們喜歡這段視頻。

Please like, subscribe and do all those other things.

請點贊、訂閱並做其他所有事情。

And as always, thanks for watching.

一如既往，感謝您的收看。

To understand that, I just post hold.

要理解這一點，我只需按住按鈕。