There are roughly 102,465 commercial flights each day which, over a year, equates to about four billion air passengers per year.
世界上每天都有大概102,465個班次的商業(yè)航班，換算成一年，差不多就是40億人次。

That's over half of the world's population who've sat on a flight, often for hours on end, and had time to think about planes and ask questions about them.
這所有坐過飛機的人已經超過地球人口的一半了，而且他們通常一坐就是幾小時，有充足的時間來思考飛機的方方面面并對它們提出問題。

If you've ever stared out the window as your plane takes off, you will have seen a tiny hole in your window.
如果你曾經在飛機起飛的時候盯著窗外看，你會發(fā)現窗子上是有小洞的。

At first, it may seem like a weird addition, especially in something that's carrying a lot of people at a great height, but they're there for a very important reason: to stop the cabin from depressuring.
乍看之下，這個細節(jié)很詭異，尤其是它還出現在一個載著這么多人、飛得這么高的東西上，但其實它是有重要作用的：防止機艙減壓。

As the plane gains altitude, the air pressure outside drops compared to the regulated air pressure inside the cabin.
隨著飛機的飛行高度增加，飛機外面的氣壓會低于飛機內收到調控的氣壓。

The difference between the two puts physical stress on the windows - made up of three panes of glass.
兩側的氣壓差會對窗戶造成物理壓力。（飛機的窗子是由3層玻璃組成的）

There's a small air gap in between the middle and outer panes and the hole is actually in the middle pane.
在中層玻璃和外層玻璃之間有一個空氣層，而這些小洞實際上是位于中層玻璃上的。

If you ever wondered what it's called - it's a "breather" or "bleed hole" - and it balances the pressure between the cabin and the air gap.
你可能好奇過它們叫什么。它們被稱為“呼吸孔”或者“出血孔”——它們能平衡機艙與空氣層之間的壓力。

The outer pane takes the pressure, whereas the middle pane acts as a fail-safe just in case that trusty outer pane fails. Perish the thought.
承受壓力的是外層玻璃，而中層玻璃則是一層保險，以防那層可靠的外層玻璃突然時效了。不過你還是打消這個想法吧。

So we now know the crucial function of those tiny holes in aeroplane windows which previously might have made you panic mildly.
好，現在我們已經知道飛機窗戶上那些小洞有多么重要的作用了，而這玩意以前可能會給你帶來點小恐慌。

And if you've ever wondered why aeroplane seats aren't always aligned with the windows, then there's an answer for that too.
不過你可能還好奇過：為什么不是所有的飛機座位都和窗子對齊？這也是有答案的。

It's nothing to do with safety either.
這個其實和安全問題無關。

While the entire design and engineering of planes is done to ensure passenger safety, this does not extend to seat alignment.
雖然整個飛機的外觀設計和工程學設計都是為了保證乘客的安全，但這并不包括飛機座位的對齊方式。

Some don't even have a window view.
有些座位甚至看不到窗子。（面壁的）

Airlines are essentially business who want to make money - and they make money by getting as many bums on seats as possible.
航空公司基本都是做生意賺錢的，而顯然，坐到他們飛機上的屁股越多，他們就越賺錢。

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（翻譯：能貓）