Welcome to Life Noggin.

歡迎來到 Life Noggin。

You Earthlings are pretty attached to your sun, and for good reason.

你們地球人對太陽很有感情，這是有原因的。

It provides light and heat, drives photosynthesis that makes oxygen, and helps generate weather patterns.

它提供光和熱，驅動光合作用產生氧氣，並幫助產生天氣模式。

Without it, you wouldn't exist.

沒有它，你就不會存在。

But if the sun is so great, would it be better if there was more of it?

但是，如果太陽這麼大，是不是多一些就好了？

What if the sun has twice the mass it has now?

如果太陽的品質是現在的兩倍呢？

Too much of a good thing can be a bad thing, and in this case, it would so bad that no one would survive.

太多的好東西可能是一件壞事，在這種情況下，它會如此糟糕，以至於不一個會活下來。

But before I get to that, you have to understand why mass makes a difference.

但在我說這個之前，你得先明白為什麼品質會有差別。

As you probably know, the sun is a star, and stars come in a variety of masses.

你可能知道，太陽是一顆恆星，而恆星的品質有很多種。

Generally, a star with more mass — more matter packed into it — glows brighter and hotter than one with less.

一般來說，質量較大的恆星（其中包含的物質較多）比質量較小的恆星發出的光更亮、更熱。

The smallest stars can be less than 8 percent the mass of the sun and give off only .01 percent as much energy.

最小的恆星的品質可能不到太陽品質的8%，僅發出0.01％的能量。

The largest stars can be a hundred times more massive than the sun and emit thousands of times as much energy.

最大的恆星可以比太陽大上百倍，並發出數千顆倍的能量。

Compared to these stars, the sun is actually a pretty normal mass.

與這些恆星相比，太陽的質量其實很正常。

But that doesn't make its relationship to Earth any less special.

但這並不意味著它與地球的關係就不那麼特殊。

Many planets are either too close or too far away from their stars to support life.

許多行星要麼離恆星太近，要麼離恆星太遠，無法支持生命。

Earth is in what we call the Goldilocks Zone, or the habitable zone, where it's just far enough away from the sun to have the right temperature for life to exist.

地球位於我們所說的「宜居帶」，那裡與太陽的距離剛好，有適合生命生存的溫度。

And we're not the only planet like this.

而且我們不是唯一一個這樣的星球。

Scientists believe there are billions of Earth-like planets in habitable zones across the Milky Way!

科學家們認為，在銀河系的可居住帶中，有數十億顆類地行星！

In fact, in early 2017, NASA announced they'd found seven exoplanets 39 light years away that might have water, and three of them are in their star's habitable zone.

事實上，2017 年初，NASA 宣布他們在 39 光年之外發現了七顆可能存在水的系外行星，其中三顆位於其恆星的宜居帶內。

But all of them orbit their star closer than Mercury orbits the sun, so… why don't they burn up?

但它們的軌道都比水星繞太陽的軌道要近，所以他們為甚麼沒有燒起來？

Well, distance is only part of the equation.

嗯，距離只是等式的一部分。

These planets orbit an ultra-cool, very small dwarf star only 8 percent as massive as the sun.

這些行星圍繞著一顆超冷、非常小的矮星運行，其質量只有太陽的 8%。

It's also half as cold as the sun and less than one-thousandth as bright.

它的溫度也只有太陽的一半，亮度也不到太陽的千分之一。

Being close to this star is the only way the planets could possibly capture enough light and heat to support life.

靠近這顆恆星是行星捕捉足夠的光和熱來維持生命的唯一途徑。

If they were farther away, they would be too cold for life to exist.

如果它們離得更遠，它們就會太冷，生命就不會存在。

So, back to your solar system.

所以，回到太陽系。

If the sun were twice as massive as it is now, Earth would fall out of the habitable zone… way out.

如果太陽的質量是現在的兩倍，地球就會脫離宜居帶……完全脫離。

First off, with more mass, the sun's luminosity — the amount of energy and brightness it gives off — would increase exponentially.

首先，隨著質量的增加，太陽的光度（它發出的能量和亮度）將呈指數級增加。

To see what might happen to you, let's look at Sirius A, the brightest star in your sky.

為了看看你會發生什麼，讓我們看看天狼星A，天空中最亮的星星。

It's just about twice as massive as the sun but more than 20 times as luminous.

它的體積大約是太陽的兩倍，但光度卻是太陽的20多倍。

It's also several thousand degrees hotter — well over 9000 degrees celsius, compared to 5500 degrees for the sun.

與太陽的 5500 度相比，它的溫度也高出數千度——遠遠超過 9000 攝氏度。

If the sun was that massive and Earth kept the same distance from it, you'd be toast, maybe literally.

如果太陽那麼大，而地球與它保持同樣的距離，你就會被烤焦，就是字面上的意思。

Earth would not just get significantly hotter, but the oceans would boil away, leaving a vapor cloud that would trap even more heat.

地球不僅會變得更熱，而且海洋會沸騰，留下一個蒸汽雲，會捕捉更多的熱量。

Plus, if the sun doubled in mass, its gravitational pull would increase.

另外，如果太陽的質量增加一倍，它的引力就會增加。

All of this would not be good for you Earthlings.

這一切對你們地球人來說都不是好事。

I think it's probably better to appreciate the Sun you have now.

我想，也許還是好好珍惜現在的陽光吧。

Let us know in the comment section below what you want us to talk about next. We're taking suggestions for future videos.

請在下面的評論部分告訴我們你希望我們接下來討論什麼。我們正在聽取有關未來影片的建議。

And are you curious to know what would happen if the Earth doubled in size?

你是否想知道如果地球大小增加一倍會發生什麼？

Check out this video.

看看這個影片。

As always, my name is Blocko, this has been Life Noggin. Don't forget to keep on thinking.

一如既往，我的名字是 Blocko，這是 Life Noggin。不要忘記繼續思考。