The answer is: we don’t know.

答案是：無法得知

You’re probably thinking: how can we not know? I mean, we’ve all got water.

你們可能會想：我們怎麼可能會不知道？我的意思是，我們有的就只是水而已

Most of us have a freezer. This seems like a pretty simple experiment.

大多數的我們都有冰箱。這實驗似乎相當簡單

Well you’re right, it is… it also isn’t.

恩，你們是對的。但，也不是件簡單的實驗

The experiment has been performed, by brilliant people all over the world.

這個實驗已經被許多世界各地的優秀人才所實踐過

And in those experiments, SOMETIMES hot water freezes faster than cold water. And sometimes it doesn’t.

而在這些實驗中，「有時」熱水比冷水更快結冰。但，有時卻沒有

And either way, the results of the experiment are not reproducible.

不管怎麼樣，這實驗的結果不是可再現的

The observation that hot water will freeze faster than cold water is called the Mpemba Effect.

觀察之下，熱水會比冷水更快結冰的現象名為「彭巴效應」

It’s named after Erasto Mpemba, who noticed the effect in 1963

是1963年，由一位Erasto Mpemba（坦尚尼亞的一位中學生）所提出與命名的

when he was just thirteen years old and making ice cream with his classmates.

13歲時，他與同學一起做冰淇淋

He noticed that the ice cream mixture made with hot milk froze faster than the mixture made with cold milk.

他發現，用熱牛奶做的冰淇淋比起冷牛奶更快結冰

However, he wasn’t the first person to make this claim. Aristotle said the same thing in the year 4 BCE.

但是，他並非第一位提出來的人。在西元前4年，亞里斯多德也曾提出相同的理論

Just, you know, not about ice cream. René Descartes and Francis Bacon

只不過不是你們所認知的冰淇淋。勒內．笛卡兒和法蘭西斯．培根

also believed that hot water froze faster than cold water.

也深信熱水能比冷水更快結冰

But scientists aren’t convinced that the Mpemba Effect is actually a thing.

但，科學家們卻不認為這樣的彭巴效應是個理論

Here’s the problem. When you have ANY two samples of water - that’s just ordinary tap water -

這裡有個質疑。你們有「任何」兩種類的水－常見的水龍頭水－

one of them will ALWAYS freeze first. That’s because the mixture of impurities in the water will be slightly different.

他們其中一個「總是」會先結冰，那是因為每個水中的雜質會有所不同

And differences in the composition, size, and position of those impurities can make the freezing point of water vary by several degrees.

像是雜質的成分、容量、與狀態會使得水的結冰點會有所變化

Hot tap water will freeze before cold distilled water, if you control for all other conditions,

如果你們有控制可能會影響的因素，熱的水龍頭水比蒸餾冷水更快結冰

because the impurities in the tap water mean that it just...freezes at a higher temperature.

因為水龍頭水的雜質需要較高的溫度來結冰

So in that case, the hot water will freeze first, but not because it’s hot.

所以，那樣的情況下，熱水會先結冰。但，不是因為他是熱水的原因（雜質因素）

If the Mpemba Effect IS a thing, and warmer water really DOES freeze faster, there are a lot of theories for why that might happen.

如果彭巴效應「是」個理論，熱水「真的」更快結冰的話，那有許多種可能的解釋方式

Evaporation is the simplest and probably the best one. Some of the hot water will evaporate as it cools,

蒸發是最簡單常見的解釋現象。有些熱水冷卻後，會因而蒸發

meaning there’s just less water to freeze, so it doesn’t take as much time.

指的是剩下較少的水能結冰。所以，相較而言不用花太多時間（來結冰）

But the Mpemba Effect has been observed while using sealed containers, which prevented evaporated water from escaping.

但，為了要應證這樣的彭巴效應，也使用過完全密閉的容器，來防止水分蒸發的情況

Other researchers who have looked into the Mpemba Effect claim is has to do with convection currents

其他的研究員也研究這個彭巴效應，而提出對流的解釋

-- the way the water moves around as it heats. Or covalent bonds.

－－加熱過程中的熱水流動方式。或是相互作用

Or how hot water holds less dissolved gas, which maybe does...something. They’re not really sure.

經過沸騰，熱水怎麼保有較少的溶解氣體。但，他們都沒有確切的解釋

Want to test it yourself? Stick some water in your freezer and see if you notice something weird.

想要自己實驗看看？放些水到你們的冰箱中，自己看看會有哪些奇特的事情發生！

Who knows, maybe you’ll get an effect named after you.

誰知道，說不定之後某效應會由你們的名字來命名

Thanks for asking, and thanks to all of our patrons on Patreon who keep these answers coming.

謝謝你們提出的疑問，也謝謝贊助Patreon的贊助商，能讓我們持續地得到答案

If you’d like to submit questions to be answered,

如果你們想提出問題並且得到答案

or get these Quick Questions a few days before everyone else, go to patreon.com/scishow.

或是想比別人更早一些看到這些問題，歡迎來到patreon.com/scishow.

And don’t forget to go to youtube.com/scishow and subscribe!

也歡迎來看看我們的頻道youtube.com/scishow，並且訂閱哦！