Name: 銀河系裡有一隻鴯鶓？釐清銀河究竟是如何誕生的 (The Milky Way: Dark Constellations, A Black Hole & Our Galaxy)
Uploaded: 2021-10-17T21:01:10.000Z
Duration: 6 min 10 s

The Milky Way is perhaps one of the most striking features in the night sky, especially if you're someplace really dark, during the right season, and even better if you're in the southern hemisphere.

銀河估計是夜空中最引人矚目的景緻了，特別是當你在對的季節身處在非常昏暗的環境下時，而如果你人在南半球的話甚至還會更美。

And long before humans knew what they were looking at was actually our home galaxy, they used their imagination to comprehend this bright band stretching across the sky.

早在人類尚未知曉自己在欣賞的其實是我們做為家園的銀河系之前，他們便已經利用想像力來解釋這一條在天空中璀璨亮眼的光條。

進階被動語態

While we may typically be drawn to the bright lights in the Milky Way, in the past, some cultures paid more attention to the darkness.

雖然我們通常是被銀河的光亮所吸引，但在過去，有些文化則對點綴其中的黑暗更感興趣。

And it turns out that focusing on the dark in the Milky Way is a pretty good place to start to figure out what our galaxy is made of. 

而仔細觀察銀河中潛藏的黑暗，其實是個開始瞭解我們星系是如何組成的好方法。

Among those who embrace the dark dusty lanes of the Milky Way, rather than the bright spots, were Aboriginal Australians.

其中一群擁抱銀河之中的黑暗而非光亮的人，便是澳洲原住民。

They saw the Milky Way as a river in the sky, filled with black water holes filled with fish, or evil spirits.

他們將銀河視為天空中的一條河，而黑色的水坑中充滿著魚群或是惡靈。

The areas they identified are known as dark constellations.

One of the most well known dark constellations is the emu in the sky.

而其中最為知名的黑暗星座便是「空中鴯鶓」。

Its body is outlined by the bulge in the constellation Scorpius and Sagittarius.

它的身體輪廓由天蠍座與射手座所勾勒出來。

Its head is formed by a massive dark nebula closer to the Southern Cross known as the Coalsack.

而它的頭則是由靠近南十字星，被稱為煤袋星雲的暗星雲所構成。

And the Australians weren't alone; all the way across the world, the Incans thought that Earth was floating in a massive cosmic ocean, and that the Milky Way was a connecting river.

不只澳洲人這麼想；遠在地球的另一端，印加人認為地球漂浮在一片廣闊的星際海洋中，而銀河則是連結的河流。

What's fascinating is that many of the dark areas that attracted these ancient astronomers actually tell us a lot about the makeup of our galaxy.

令人讚嘆的是，這些吸引了古代天文學家們目光的黑暗區域，其實能告訴我們許多關於銀河究竟是如何組成的資訊。

The name "Milky Way" has origins in both Ancient Latin and Greek, both referencing its milky quality.

「銀河 (Milky Way)」來自古拉丁文與古希臘文，指的都是其如牛奶般的特質。

That milky quality comes partly from the billions of stars that stretch out so far in one direction, that it's difficult for our eyes to pick them out individually.

這種乳白色的外表部份來自於數以十億計的恆星們在同一個方向上延伸出去，距離遠到讓我們的眼睛難以一顆顆分開來辨別。

This perspective of the Milky Way is actually what helped astronomers figure out what the galaxy looks like, and where we're sitting in it.

而銀河的這個特點正是幫助天文學家們瞭解銀河看起來是什麼樣子，還有我們其實正身處其中的原因。

By measuring the distance to a bunch of these stars and seeing how some move toward us, and others away, we can see that the stars are moving in an overall rotational motion.

通過測量與這些恆星間的距離並觀察這些恆星如何移動的，我們可以看到部分的恆星正在靠近我們，其他的恆星則在遠離我們，並藉此發現所有的恆星整體來說正在以一種不斷繞著圈的方式移動。

This tells us that the entire galaxy is rotating in a big uniform spiral.

這讓我們得知整個銀河系其實正在一起螺旋旋轉著。

We also know that our sun sits on the edge of one minor arm of the spiral.

我們還瞭解到我們的太陽就坐落在螺旋當中，一個長臂上的邊緣位置。

And the fact that we can see the Milky Way from Earth as a straight line across the sky, with a heavy concentration of stars in the center, means that we're looking at it from just inside the far side.

而我們能從地球的天空上看到呈直線，且大部分恆星在中央部分的銀河，代表我們正在從銀河內部，靠近邊緣的遠處往中間看去。

The center of our galaxy is actually something that you can see with the naked eye—just look at the part of the Milky Way right between Sagittarius and Scorpius.

而你其實用肉眼就可以看到銀河的中心－就在摩羯座與天蠍座之間之間。

Then there are a few layers in the Milky Way: chocolate, caramel, nougat....

銀河裡分成了幾層：巧克力、焦糖、牛軋糖......

If there were a caramel layer, it would be that super dense stripe across the middle.

如果真的要說哪一層是焦糖層的話，那一定是那個橫跨中心，超級密集的那條線。

So this is called the thin disk, and the thin disk of the Milky Way is where there's a lot more stars. 90% of the mass in the Milky Way exists in the Milky Way thin disk.

這就是所謂的薄盤，而銀河系的薄盤中有著比厚盤更多的恆星。銀河 90% 的質量都存在於薄盤中。

And this is also where gas settles and forms stars, so that's why there's the dark patches of dust. And if there's gas and dust, there's, you know, a place for possible star formation.

而這裡也是氣體停下來並形成恆星的地方，而這就是為什麼其中會有以塵埃組成的暗斑的原因。只要有氣體和塵埃，就有機會形成出新的恆星。

This is my friend Dreia Carrillo. She's a galactic archaeologist, yes, coolest title ever! Who studies what the Milky Way is made of.

這是我的朋友 Dreia Carrillo，她是一位星際考古學家。沒錯，真是史上最酷的職稱了對吧！她專門研究銀河系的組成。

And there's actually a puffier thick disk.

而其實除此之外，還有一個更蓬鬆的厚盤。

So the thin disk and the thick disk are made up of stars born in the Milky Way.

薄盤和厚盤都是由在銀河中誕生的恆星所組成的。

The thick disk, was likely thinner, but its stars were heated up and their orbits disrupted.

厚盤就像薄盤一樣，但上面的恆星們更熱，且軌道混亂。

How galaxies form is smaller galaxies get eaten up by larger galaxies, and this is called galactic cannibalism.

星系的行程方式是由較大的星系吞併較小的星系，而這個過程被稱為星際併吞。

And this disrupts the stars, making the layer puffy.

這個過程會打亂恆星軌道，並讓分層膨脹。

 And then there's an extended halo around these two layers, made up mostly of stars that were born in other galaxies, like a big stellar graveyard.

而這兩層的外圍還有一個擴展出去的光環，裡面主要是誕生自其他星系的恆星，就如同一個巨大的恆星墳場那樣。

There's also the bulge, a densely packed region of stars around the center of the galaxy.

而銀河的中央附近則有一塊許多恆星密集聚集的凸起區域。

And, of these layers, the thin disk and the bulge are all you can really see from Earth.

在這些層次中，在地球上我們僅能觀察到薄盤和中央的凸起。

Those dark spots in the thin disc that the Aboriginal Australians and the Incans focused on so long ago, are actually massive dust clouds from the formation of new stars in the galaxy.

澳洲原住民與印加人在遠古時期所觀察到的銀盤上的黑色區域，其實是銀河中有新恆星誕生時所產生的巨大塵埃雲朵。

Knowing these different components of the Milky Way is helping scientists like Dreia, figure out how the galaxy formed in the first place.

瞭解銀河中不同的組成，能夠幫助像是 Dreia 這樣的科學家釐清銀河究竟是如何誕生的。

So stars have locked into them some kind of signature of the conditions that they were born in which we see in their chemistry, and that also is different if you're in different parts of the galaxy,

我們可以藉由分析恆星的化學成分，來了解它們在誕生時便已鎖定下來，對於狀況的某種紀錄，而這樣的成分會因為恆星在星系的不同地區，

or if you're from another galaxy and got cannibalized by the Milky Way.

或是原本屬於其他星系但後來被銀河系吞併了而有所不同。

So chemistry is like a very important property that we try to measure in order to kind of backtrack, the formation and evolution of galaxies.

所以化學成分是我們去循線追回銀河的形成與演變所需的重要因素。

It's pretty amazing that we can look up at the Milky Way, from our little planet and know that we're staring at our own galaxy.

能從我們的小小星球抬頭仰望銀河，並知曉我們其實正盯著自己所處的星系看，真的是很棒的一件事。

In fact, every star you can see with the naked eye is within the Milky Way, even the ones not concentrated in the obvious stripe.

事實上，你用肉眼便能觀察到銀河系中的每一顆恆星，就連沒有明顯以條狀方式聚集在一起的星星都能看見。

If the sky is dark enough, you'll be able to pick out the center of our galaxy, the thin disk, some dark dusty nebulae, and the giant emu in the sky.

如果天色夠黑，你便能看見銀河系中心、薄盤、一些暗星雲，還有天空中巨大的鴯鶓。

And maybe one day we'll know more about how the galaxy was formed and where all its parts come from.

而或許有一天，我們能夠對星系的形成方式，以及其組成究竟從何而來瞭解得更為透徹。

I'm Sarafina Nance, and this is Seeker Constellations.

我是 Sarafina Nance，以上事 Seeker 星座節目。

We're going to be covering all kinds of topics to do with the stars and astronomy, so let us know down in the comments if there's something you want us to cover.

我們之後將會探討各式各樣有關星星與天文學的話題，所以請在下面留言中告訴我們你想要我們討論的題目吧。