這個世界上真有第二個你 機率是……

Most of us have, at some point in time, been told we have a doppelgänger - someone out there who looks just like us. But what are the chances, scientifically speaking, of that happening?

我們大多數人都曾在某個時間點被告知，自己有一個二重身——那兒有個人看上去很像我們。但從科學的角度來講，發生這種事的可能性有多大？

According to the research, having an exact doppelgänger is less likely than you might think. A study crunched the numbers and investigated the probability of two people matching up exactly in eight key facial features.

研究指出，擁有一模一樣的二重身的可能性比你想象中的要小。一項研究處理了大量數據信息，探討了兩個人在8個關鍵面部特徵上完全吻合的可能性。

They found that there's about a one in 135 chance that a pair of complete doppelgängers exist somewhere in the world. But the likelihood of someone walking around looking identical to you, specifically, in all eight facial features is only one in 1 trillion. Creepy, but not very likely.

他們發現在世界上的某個地方存在一對完美的二重身的可能性大約爲1/135。但是走在路上的某個人看上去跟你一樣的可能性，特別是8個面部特徵都相同的人，這種可能性只有萬億分之一。聽上去挺恐怖的，但卻不太可能。

So why do people keep telling you they saw someone that looks "just like you" if that's so statistically unlikely?

那麼，既然從統計學的角度來講，這是不可能的，爲什麼人們還是不斷告訴你他們看到了一個“看上去很像你”的人呢？

The issue here is that people can perceive faces differently. This means that – even though a person might not be a true doppelgänger – we might think they are because we cannot calculate the minuscule measurements of their facial features.

這兒的問題就是人們對面孔的感知是不同的。這意味着，儘管一個人可能不是一個真正的二重身，但是我們可能會認爲他們是，因爲我們無法估量出他們面部特徵的細微尺寸。

In other words, it's quite likely to have a doppelgänger out there that your friends think looks exactly the same as you, but if you were to analyse their features scientifically, it's unlikely they'd be a true match.

換句話說，很可能那兒有一個二重身，你朋友認爲看上去跟你一模一樣，但如果你科學地分析一下他們的特徵的話，他們不可能跟你一模一樣。

While the findings are just plain cool to think about, the team also says that they suggest that facial recognition might be as good as fingerprinting or DNA in catching wanted criminals.

這個發現想想還是很酷炫的，同時，研究團隊還指出，他們認爲在追捕通緝犯的時候，面部識別也許與指紋或DNA識別一樣管用。