And, what I'm gonna show you today is that there are good ways and there are bad ways of cutting a cake.

今日我要跟你們說明切蛋糕的方式有好也有壞

And the classic way, the bad way, is like this, which will be normal.

最經典的方式 也就是不好的方式 就像這樣 很平常

You put the knife in the center, one bit of a slice, a bit of a slice.

你將刀切入中心 這樣一切 再一切

That's not the classic.

這不是經典的方式

It is the classic, isn't it? It's almost like a pie chart.

這是經典的方式 不是嗎？這看起來幾乎像是個圓餅圖

You know one thing about the word pie chart, in France,

你知道 在法國 「圓餅圖」這個字

they call them, Camembert, which is like a cheese.

他們叫做 卡門貝 一種起司

It actually got a cheese chart in France.

法國甚至還有一種起司圖表

Interesting cultural differences. enough speak

有趣的文化差異 說夠了

So, this is what you'll do, you take this, you'd put this over here.

所以 你要做的是 拿起這個 然後放去那邊

You eat it, and you leave this in the fridge overnight.

你吃掉它 然後將這放入冰箱過夜

And the reason why this is a really bad way of cutting a cake,

而這就是為何這是一個不好的切蛋糕方式

is that these bits here are just going to get dry.

因為這些地方就會變得乾燥

And so when you come the following day to have your cake,

所以當你隔天要享用蛋糕時

you do another one, another slice like this,

你像這樣再切一次 像這樣的另一片

This side here, lovely and soft. This will be dry and horrible.

這一邊 美好又軟綿 而這一邊 又乾又糟

You know, maximizing the amount of gastronomic pleasure that you can make from this cake

你知道 想要使這蛋糕的美味愉悅程度提昇至最高點

there is a better way. A way that is more than a hundred years old,

有更好的辦法 而這個方式有100年的歷史

and was discovered or invented by one of Britain's most famous and brilliant mathematical scientists.

是英國最知名及聰明的數學家之一所發現及發明的

This is a copy of Nature, the famous science magazine from December 20th, 1906.

這是1906年12月20號 Nature這本知名科學雜誌的複本

In the letters to the editor here it says, headline, Cutting a Round Cake on Scientific Principles

在給編輯者的信中 標題寫道 在科學的原則下切圓形蛋糕

The ordinary method of cutting out the wedge is very faulty

平常切成楔型的作法是大錯特錯的

What he suggests is, and he gave a illustration for it,

他所提議的是 並附上圖片

tha proper way, the scientific way, the mathematically perfect way of cutting a round cake, and it is as follows.

一個正當的 科學的 數學上完美的切圓形蛋糕之作法，如下

So, we have another cake. The first slice will be like this.

所以我們有另一個蛋糕 第一刀會像這樣

It's breaking all the rules of a cake etiquette. Perfect. Okay. So, this is the first one.

這是在打破蛋糕禮儀的所有原則 完美 OK 所以這是第一片

And then I need to find a way of taking it out. We can set that there.

然後我得找個方式把它拿出來 我們可以放在那

That's gotta be the prime steak of that cake, isn't it? It's the t-bone cut.

這根本是蛋糕中的頂級牛排 不是嗎？ 這是丁骨牛排

Here we need to do, we need to close the cake together like this, and it's gonna come apart.

我們需要做的是像這樣將蛋糕合起來 然後它會分離

So look what I got here, I have got some rubber bands to make sure it stays together.

所以你看我準備了些橡皮筋來讓它密合在一起

The following day, all the flesh, the sponge is going to be nice and soft.

隔天 所有的蛋糕體都會完好又柔軟

So, how do they do the second slice? The second slice, because it's not your birthday anymore,

所以如何切第二片呢？ 第二片時 因為已經不是你的生日了

so you're not gonna have this slice quite as big. Interesting to work out that actual proportion.

所以這片不會這麼大片 切出實際比例真有趣

This is, and you got a lovely break into the elastic band too. it's exciting

這 然後你也會美好的切斷橡皮筋 真的很刺激

This is slice two, or it actually is slice two which has two slices, two parts.

這是第二片 其實是有兩片 兩塊的第二塊

Good. So you put this back together. And we can keep on going,

很好 然後把這合起來 我們就可繼續

Obviously again I want to use the elastic band to put the cake together.

很明顯地 我要再用橡皮筋來密合蛋糕

That is perfect. That's gonna stay so fresh for day 3. Day 3, how should we do day 3 again?

完美 這樣第三天也會很新鮮 第三天 我們要怎麼切？

Let's, um, turn it around. I think this is gonna be the slice for day 3.

讓我們 嗯 把它轉過來 我想這會是第三天的蛋糕切片

Again, the satisfying snap of the elastic band.

再一次的 令人滿意的橡皮筋斷裂聲

I don't know if you thought of them before, but this triangular slices are really annoying anyway because it's not very satisfying.

不知道你是否曾想過 但三角形的切片不管怎麼說真的很惱人 因為這令人很不滿

Having a nice uniform slice like that is a lot better.

像這樣有完好一致的切片好多了

So, here we go again, it's the end of day 3.

所以 又來了 第三天結束了

And this is gonna be perfect, and gradually, we are slicing it. Keep on going.

這會很完美 逐漸的 我們正在切它 繼續加油

I think for the, um, mathematical loners, who don't want to share their cake, it can be useful.

我認為 這對於不想跟他人共享蛋糕 數學上的孤僻者來說 非常實用

For a bit more interview including more about the guy who came up with this cake cutting method, have a look of the extra footage over on Numberphile2.

想要了解關於這切蛋糕方法的發明者的更多訪談資訊 請看Numberphile2的其他影片

And if you just like to hear more great stories from Alex, he's got a new book out just recently,

而你若想聽更多Alex講的精采故事 他最近有新出書出版了

Alex Through the Looking Glass, How Life Reflect Numbers and Numbers Reflect Life

《艾力克斯的夢遊仙境 人生如何反應數字 數字如何反應人生》

It's really good, it's also just out in the US, but it has a different name in the US.

這真的很棒 在美國也剛上市 但書名不同

It's called, The Grapes of Math. I will put links to it in the video description.

叫做 數學的葡萄(英文音似憤怒的葡萄) 我會在影片敘述的地方放上連結