時(shí)差N小時(shí):每年400天 400 Days Per Year

Yael, do you notice the days changing length overthe course of the year?

雅埃爾，你有沒(méi)有注意到一年中每一天的長(zhǎng)度在改變么?

Sure, Don, it stays light later in the summer andgets dark earlier in the winter.

當(dāng)然了，唐，夏天白天長(zhǎng)些，冬天天黑得早些。

No, that's not it. I mean the whole day feels longer.

不，我說(shuō)的不是這件事。我的意思是一整天感覺(jué)變長(zhǎng)了些。

I'm not sure that's possible, Don aren't days always24 hours long?

我不確定它是不是真的，難道一天不總是24個(gè)小時(shí)么?

Well, it actually takes 23 hours, 56 minutes, and 4 seconds for the Earth to rotate on its axis.

其實(shí)，實(shí)際上，地球繞地軸自轉(zhuǎn)一周需要23小時(shí)56分零4秒。

But in fact the Earth's rotation is slowing down all the time because of the gravitational pullof the moon.

但實(shí)際上，因?yàn)橛性虑虻娜f(wàn)有引力作用，地球自轉(zhuǎn)一直在變慢。

Does this mean that the days really do feel longer?

這就意味著一天真讓人覺(jué)得變長(zhǎng)了?

Nope. The moon slows us down byabout two milliseconds a century, so that even 1 million years ago days were only twentyseconds shorter.

不。每過(guò)一個(gè)世紀(jì)，月球使我們慢了2毫秒。因此，即使比起一百萬(wàn)年前的某一天，現(xiàn)在也僅僅慢了20秒。

I doubt I would have noticed that.

人們會(huì)注意到么?

Maybe not a million years ago. But 400 million years ago days were 21 and a half hours long,which you would have noticed.

可能不是一百萬(wàn)年前，而是4億年前的某一天，當(dāng)時(shí)一天長(zhǎng)21.5小時(shí)，這樣你可能就能注意到。

What you really would have noticed is that the time it takes the Earth to get around the sunhasn't changed, so that back then there were 400 days a year.

你真正能意識(shí)到的是：地球繞著太陽(yáng)公轉(zhuǎn)的時(shí)間沒(méi)有改變，所以那時(shí)一年有400天。

Scientists have found fossil evidence from tropical corals that existed at that time, and theyhave about 400 daily growth rings per year.

從存活在那時(shí)的熱帶珊瑚中，科學(xué)家已經(jīng)發(fā)現(xiàn)了化石證據(jù)。它們每年大約有400個(gè)生長(zhǎng)日輪。

So someone was enjoying all those extra sunny days.

所以過(guò)去的人能享受這些多出來(lái)的日子。