哇!多么美麗的夕陽(yáng)啊!
Enjoy it while it lasts, the sun won't be aroundforever, you know.
盡情欣賞吧,太陽(yáng)不會(huì)永遠(yuǎn)存在的。
You mean, one day the sun will disappear?
你的意思是,有朝一日太陽(yáng)會(huì)消失?
Not exactly disappear, but the sun will eventuallyburn out and die.
不是完全消失,太陽(yáng)的能量最后會(huì)耗盡并枯竭。
Won't that make things really cold down here?
那樣的話,地球就會(huì)變得很冷了。
Actually, there won't be any here, here.
實(shí)際上,那時(shí)地球就不存在了。
When the sun dies,the earth will be destroy too.
沒(méi)有了太陽(yáng),地球也將毀滅。
Wow, hold on, start from the beginning.
等一下,你從頭開(kāi)始說(shuō)。
Okay. Like all stars, the sun is basically a giant nuclear reactor that burns hydrogen tocreateenergy.
好的。像所有的行星一樣,太陽(yáng)從根本上說(shuō),是一個(gè)巨型核反應(yīng)堆,通過(guò)燃燒氫氣產(chǎn)生能量。
But like any reactor, the sun needs fuel to keep going.
但是,就像任一反應(yīng)堆,太陽(yáng)需要燃料來(lái)保持運(yùn)作。
It's been going strong for around four-point-five billion years, and will probably keep burning forabout five billion more.
它已經(jīng)良好運(yùn)作大約45億年了,并且將會(huì)持續(xù)燃燒50億年左右。
But then, the fuel will run out?
到那時(shí),燃料就會(huì)耗盡。
Exactly. When it does, gravity will cause the sun's core to contract.
是的。當(dāng)太陽(yáng)能量耗盡,地心引力會(huì)使得太陽(yáng)核心縮小。
When it contracts the corewill get hotter, which will heat up the sun's upper layers and makethem expand.
縮小地同時(shí)溫度變得更得高,這樣就加劇了太陽(yáng)外層的燃燒并使其膨脹。
The sun will then become what's called a red giant, and its radius will reach just past the orbitof Venus.
太陽(yáng)就變成了所謂哦紅巨星,它的半徑將會(huì)達(dá)到以前金星的運(yùn)行軌道。
Which is bad for us.
那樣會(huì)對(duì)我們有害。
We'll be burned to a crisp.
我們會(huì)被燒成土豆片的。
That's sounds painful.
聽(tīng)起來(lái)很痛苦。
After a few billion years the core will begin to cool and expand.
數(shù)十億年后太陽(yáng)中心開(kāi)始冷卻并擴(kuò)大。
The sun's upper layers will expand and lose material, and eventually the core will cool enoughto become a white dwarf star,and finally a black dwarf.
太陽(yáng)的上層也將擴(kuò)大,失去物質(zhì)重量,最后中心冷卻到一定程度就成了白矮星,最終成黑矮星。
So, we're pretty much doomed.
那時(shí),我們就注定要完蛋了。
Yes, but not for billions of years.
是的。但那是幾十億年以后的事了。
Who knows? By then, human's might been living on anotherplanet.
誰(shuí)知道呢?到那時(shí),人類(lèi)也許已經(jīng)生活在另一個(gè)星球上了。