英語(yǔ)四級(jí)翻譯：那些復(fù)雜到讓你困惑的簡(jiǎn)單小事(9)

英語(yǔ)四級(jí)翻譯：那些復(fù)雜到讓你困惑的簡(jiǎn)單小事(9)

9.The Definition Of 'Almost Surely' Is A Mathematical Nightmare

對(duì)"幾乎必然"的定義是數(shù)學(xué)上的一個(gè)噩夢(mèng)

If we were to say that a given event was almost sure to happen, how would you explain that to a small child? Maybe you'd say that the event was practically guaranteed, but then you'd have to explain what "practically" meant in regards to that sentence, which would just confuse things further. It's a tough question because the concept of something being "almost sure" to happen is so vague in and of itself.

如果我們說(shuō)一個(gè)給定事件幾乎必然要發(fā)生，你會(huì)如何向一個(gè)小孩子解釋?也許你會(huì)說(shuō)這件事幾乎已經(jīng)確定要發(fā)生，但稍后你還得解釋在這句話中"幾乎"是什么意思，而這會(huì)使事情更難理解。這是一個(gè)很難回答的問(wèn)題，因?yàn)槟臣?幾乎必然"要發(fā)生的概念本身就是含糊不清的。

Luckily for us all, the concept exists within statistical mathematics, which explains it fully. Unluckily, it's incredibly intimidating at first glance. To quote an online math textbook on the concept:

對(duì)我們來(lái)說(shuō)幸運(yùn)地是，這一概念存在于統(tǒng)計(jì)數(shù)學(xué)中，統(tǒng)計(jì)數(shù)學(xué)充分地解釋了這一概念?？刹恍业厥牵y(tǒng)計(jì)數(shù)學(xué)對(duì)這一概念的定義乍一看卻極度讓人生畏。引用一本在線數(shù)學(xué)教科書對(duì)此概念的定義：

"In probability theory, a property is said to hold almost surely if it holds for all sample points, except possibly for some sample points forming a subset of a zero-probability event."

"在概率論中，如果除去一些可能構(gòu)成一個(gè)零概率事件子集的樣本點(diǎn)，其他的樣本點(diǎn)都具有某種特性，那么我們就說(shuō)這種特性是'幾乎必然'存在的。"

In more basic language, that essentially means that even when an event has a 100 percent chance of occurring, it won't necessarily occur. For example, if you flipped a coin a million times, statistically, the odds of the coin landing on heads at least once is essentially one. However, there is an infinitesimally small chance that the coin could land on tails every single time. So although the odds of the event happening are for all intents and purposes guaranteed, it is impossible to say that.

更通俗地來(lái)說(shuō)，上述定義本質(zhì)上意味著即使一個(gè)事件發(fā)生的幾率為百分之百，它也不一定就會(huì)發(fā)生。比如，你將一個(gè)硬幣拋一百萬(wàn)次，從統(tǒng)計(jì)學(xué)上來(lái)說(shuō)，硬幣落下時(shí)至少有一次是正面朝上的概率基本上是1。然而，每次拋硬幣時(shí)都存在極小的概率-硬幣落下時(shí)是反面朝上的。因而即使確定一個(gè)事件發(fā)生的概率為百分之百，也不可能說(shuō)它就一定會(huì)發(fā)生。

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