The most detailed map of galaxies, black holes and stars ever made | Juna Kollmeier

譯者: Amanda Zhu 審譯者: Bruce Sung

When I was a kid, I was afraid of the dark.

我小時候很怕黑。

The darkness is where the monsters are.

黑暗是怪獸出沒的地方。

And I had this little night light outside of my bedroom

我的臥室外有盞小夜燈，

so that it would never get too dark.

這樣房間裡就不會一片漆黑。

But over time, my fear of the dark turned to curiosity.

但隨時間過去， 我對黑暗的恐懼變成了好奇。

What is out there in the "dark-dark?"

「暗暗」中有些什麼？

And it turns out

結果發現，

that trying to understand the darkness is something that's fascinated humans

數千年來，也許更久， 人類一直在試圖了解黑暗，

for thousands of years, maybe forever.

對於黑暗深深的著迷。

And we know this

我們會知道這點，

because we find their ancient relics of their attempts to map the sky.

是因為我們在古老的遺跡中 發現先民嘗試繪製的天空圖。

This tusk is over 30,000 years old.

這個長毛象牙殘片 有 3 萬多年歷史。

Some people think that it's a carving of Orion

有些人認為上面刻的是獵戶座，

or maybe a calendar.

或是日曆。

We don't know.

我們不確定。

The Fuxi star map is over 6,000 years old,

伏羲星圖有 6000 多年的歷史，

and it's from a neolithic tomb in ancient China.

發現於古中國的新石器時代墳墓。

And that little pile of clamshells

在中間死人的腳下方有一堆蛤蠣殼——

underneath the dead guy's foot in the middle --

that's supposed to be the Big Dipper.

那應該是北斗七星。

Maybe.

可能是吧。

The Nebra disk is uncontroversial.

內布拉星象盤更是一目了然。

You don't have to be an astronomer to know that you're looking at the Moon phases

就算不是天文學家， 也能認出這是月相，

or the Sun in eclipse.

或是日蝕。

And that little group of seven stars, that's the Pleiades, the Seven Sisters.

成簇的那七顆星是金牛座的 昴宿星團，又稱七姊妹星。

But in any case, the point is clear:

無論如何，重點很清楚：

astronomers have been mapping the sky for a long time.

長久以來，天文學家 一直試圖描繪天空。

Why?

為什麼？

It's our calling card as a species in the galaxy

因為身為銀河系中的物種， 我們人類的特點就是理解事物。

to figure things out.

We know our planet,

我們了解我們的星球，

we cure our diseases,

能治癒我們的疾病，

we cook our food,

會烹煮我們的食物，

we leave our planet.

甚至能離開我們的星球。

But it's not easy.

但這並不容易。

Understanding the universe is battle.

探索宇宙是一場戰鬥。

It is unrelenting, it is time-varying,

這場戰鬥是無情的，而且變幻無窮，

and it is one we are all in together.

我們所有人都置身其中。

It is a battle in the darkness against the darkness.

這是一場在黑暗中對抗黑暗的戰鬥。

Which is why Orion has weapons.

這就是獵戶座有武器的原因。

In any case, if you're going to engage in this battle,

無論如何，如果你要參戰，

you need to know the battlefield.

就需要了解戰場。

So at its core,

所以核心概念是，

mapping the sky involves three essential elements.

繪製天空圖有三個必要元素：

You've got objects that are giving off light,

要有發出光的觀測物，

you've got telescopes that are collecting that light,

要有收集光的望遠鏡，

and you've got instruments

還要有儀器

that are helping you understand what that light is.

來幫你了解那些光是什麼。

Many of you have mapped the Moon phases over time

很多人都用肉眼觀測過月相，

with your eyes, your eyes being your more basic telescope.

肉眼是最基本的望遠鏡。

And you've understood what that means with your brains,

你也能用大腦理解那是什麼意思，

your brains being one of your more basic instruments.

大腦是最基本的儀器。

Now, if you and a buddy get together,

如果你和一位夥伴合作，

you would spend over 30 years,

費時三十年多年，

you would map 1,000 stars extremely precisely.

你就能非常精確地繪製出 一千顆恆星的地圖。

You would move the front line to the battle.

你就能把前線推到戰場上。

And that's what Tycho Brahe and his buddy, or his assistant, really,

那正是在 17 世紀 泰谷．布拉赫和他的夥伴，

或應該說是他的助手 約翰尼斯．克卜勒做的事。

Johannes Kepler did back in the 1600s.

And they moved the line,

他們將前線往前推進，

figured out how planets worked,

想通了行星如何運作、

how they moved around the Sun.

行星如何繞著太陽運轉。

But it wasn't until about 100 years ago

但直到大約 100 年前，

that we realized

我們才知道，

it's a big universe.

宇宙其實很大。

It seems like the universe is just infinite, which it is,

宇宙似乎沒有邊際， 事實也的確如此，

but the observable universe is finite.

但能觀測到的宇宙是有限的。

Which means we can win the battle.

也就是說，我們可以 在有限的範圍打贏這場仗。

But if you're going to map the universe,

但如果你要繪製宇宙圖，

you're not going to do it with one or two of your besties.

和一兩位好友合作是不夠的。

Mapping the universe takes an army,

繪製宇宙圖需要一支軍隊，

an army of curious, creative, craftspeople

一支充滿好奇心和創意， 而且技藝精湛的軍隊，

who, working together, can accomplish the extraordinary.

同心協力他們就能夠 完成非凡的任務。

I lead this army of creatives,

我領導一支這樣的創意大軍，

in the fifth generation of the Sloan Digital Sky Survey, SDSS.

參與了第五代史隆數位 巡天專案，簡稱 SDSS。

And this is how astronomers have managed to shepherd individual curiosity

在工業時代的考驗下， 天文學家們就藉此

引導個人的好奇心，

through its industrial age,

preserving the individual ability to make discoveries

保存了個人的能力，用於探索發現；

but putting into place mega machinery to truly advance the frontier.

同時投入巨型機器 來真正地擴展疆界。

In SDSS, we divide the sky into three mappers:

在 SDSS，我們將天空 分割成三個區域來探索：

one for the stars, one for the black holes

一個探索恆星，一個探索黑洞，

and one for the galaxies.

一個探索星系。

My survey has two hemispheres,

我的觀測範圍包括兩個半球，

five telescopes, or 11, depending on how you count,

使用 5 個望遠鏡—— 換個算法可能變成 11 個、

10 spectrographs

10 個攝譜儀，

and millions of objects.

以及數百萬個觀測物件。

It's a monster.

這是個龐大的計劃。

So let's go through the mappers.

接著我們來看這些區域。

The Milky Way galaxy has 250 billion plus or minus a few hundred billion stars.

銀河系有 2500 億顆恒星， 誤差可能就有幾千億。

That is not a number that you hold in your head.

這個數字大到難以想像。

That is a number that doesn't make practical sense

這個數字對任何人來說 都沒有實際的意義。

to pretty much anybody.

You never get 250 billion jelly beans in your hand. You know?

沒有人會在手裡握著 2500 億顆糖，對吧？

We're nowhere near mapping all of those stars yet.

要繪製所有恆星的圖， 我們還差得很遠。

So we have to choose the most interesting ones.

所以我們只能挑選最有趣的來做。

In SDSS-V, we're mapping six million stars

在 SDSS-V，我們要繪製 6 百萬顆恆星的位置。

where we think we can measure their age.

我們認為可以測出它們的年齡。

Because if you can measure the age of a star,

如果你能測出恆星的年齡，

that's like having six million clocks spread all throughout the Milky Way.

就好像銀河系中有 6 百萬個時鐘。

And with that information,

有了這些資訊，

we can unravel the history and fossil record of our galaxy

我們就可以解讀 銀河系的歷史和化石記錄。

and learn how it formed.

了解它的起源。

I'm just going to cut right to the chase here.

我現在要直接切入主題。

Black holes are among the most perplexing objects in the universe.

黑洞是宇宙中最令人困惑的物質之一。

Why?

為什麼?

Because they are literally just math incarnate, in a physical form,

因為它們其實就是數學的化身， 然後以實體的形式存在。

that we barely understand.

這是我們幾乎無法理解的。

It's like the number zero being animated and walking around the corridors here.

就像數字「0」變成有生命的東西， 在這裡的走廊走來走去。

That would be super weird.

超詭異的。

These are weirder.

黑洞更詭異。

And it's not just like a basketball

它不像是把一個籃球 擠壓成一個小點，密度變得很大，

that you smoosh down into a little point and it's super dense and that's weird.

也是有點詭異。

No, smooshed basketballs have a surface.

但被壓縮的籃球還是有表面。

These things don't have surfaces, and we know that now.

我們已經知道黑洞是沒有表面的。

Because we've seen it.

因為我們看過黑洞了，

Or the lack of it.

或應該說，一個沒有東西的東西。

What's really interesting about black holes

黑洞有趣的地方在於，

is that we can learn a lot about them by studying the material

透過研究物質穿過 黑洞一去不返的「極限點」，

just as it passes through that point of no information return.

我們能更了解黑洞。

Because at that point,

因為在那個點，

it's emitting lots of X-rays and optical and UV and radio waves.

該物質會釋放出大量 X 射線、 可見光、紫外線和無線電波。

We can actually learn how these objects grow.

我們可以得知黑洞如何變大。

And in SDSS, we're looking at over half a million supermassive black holes,

在 SDSS，我們觀測了 超過 50 萬個超大黑洞。

to try to understand how they formed.

來試圖了解它們如何形成。

Like I said,

我說過了，

we live in the Milky Way, you guys are all familiar with that.

我們生活在銀河系，大家都很熟悉。

The Milky Way is a completely average galaxy.

銀河系是個很普通的星系。

Nothing funny going on.

沒有甚麼奇怪的現象。

But it's ours, which is great.

但這是我們的家，很棒啊！

We think that the Milky Way, and all the Milky Ways,

我們認為銀河系， 以及所有的銀河系，

have this really disturbing past

都有一段駭人的過去，

of literally blowing themselves apart.

它們都曾把自己炸開來。

It's like every average guy you know

好比是你認識的每個普通人，

has a history as a punk rock teenager.

都曾是龐克搖滾的叛逆少年。

That's very bizarre.

這是很怪異的。

Stars are blowing up in these systems,

恆星在這些系統中爆炸，

black holes are growing at their centers

中心形成黑洞，

and emitting a tremendous amount of energy.

並釋放出巨大的能量。

How does that happen, how does this transformation happen?

這是怎麼發生的？ 這種變化是怎麼發生的?

And at SDSS, we're going to the bellies of the beast

在 SDSS，我們要深入 這個怪物的內部，

and zooming way in,

把近距離畫面放到最大，

to look at these processes where they are occurring

來觀察這些過程發生在哪裡，

in order to understand how Sid Vicious grows up into Ward Cleaver.

以便了解叛逆少年 如何變成普通人。

My arsenal.

這些是我的裝備。

These are my two big telescopes.

這是我的兩個大望遠鏡：

The Apache Point Observatory hosts the Sloan telescope in New Mexico,

新墨西哥州的阿帕奇點天文臺 設置的史隆望遠鏡，

and the Las Campanas Observatory in Chile

以及智利的拉斯坎帕納斯天文臺

hosts the two-and-a-half-meter telescope, the du Pont.

設置了 2.5 米的杜邦望遠鏡。

Two and a half meters is the size of our mirror,

2.5 米是鏡子的大小，

which was huge for Tycho and Kepler.

這對泰谷和克卜勒來說是很大的，

But it's actually not so big today.

但是和當今的望遠鏡相比， 它其實並不大，

There are way bigger telescopes out there.

有其他望遠鏡大多了。

But in SDSS we use new instruments on these old telescopes

但在 SDSS，我們在這些 舊望遠鏡上裝了新儀器，

to make them interesting.

讓他們更厲害。

We capture light from all of those objects into our aperture,

我們把所有觀測物的光 都捕捉到光圈哩，

and that light is then focused at the focal plane,

將這些光聚集在焦點平面上，

where our instruments sit and process that light.

然後我們儀器就會處理這些光。

What's new in SDSS-V

SDSS-V 的創新之處，

is that we're making the focal plane entirely robotic.

在於把焦點平面變成 全自動化機器人。

That's right: robots.

沒錯，機器人。

(Laughter)

(笑聲)

So I'm going to show them to you,

我要秀給你們看，

but they're fierce and terrifying,

它們很兇猛可怕，

and I want you all to just take a breath.

你們要深呼吸，做好準備。

(Exhales) Trigger warning.

（呼氣）敏感內容警告!

And with no apologies to all the Blade Runners among you,

就算你是銀翼殺手也要小心，

here they are.

就是它。

(Laughter)

（笑聲）

I have 1,000 of these,

這儀器我有 1000 個，

500 in the focal plane of each telescope in each hemisphere.

南北半球每個望遠鏡的焦點平面中 都有 500 個這個儀器。

And this is how they move on the sky.

這就是它們移動的方式。

So these are our objects and a star field,

這些是我們的觀測物和一個恆星場，

so you've got stars, galaxies, black holes.

有恆星、星系、黑洞。

And our robots move to those objects as we pass over them

當望遠鏡視野經過時， 機器人移動至視野中的觀測物上，

in order to capture the light

來捕捉觀測物的光線，

from those stars and galaxies and black holes, and yes,

觀測物有恆星、星系、黑洞。

沒錯，捕捉黑洞的光線聽起來很怪，

it is weird to capture black hole light,

but we've already gone over that black holes are weird.

我剛剛就說了， 黑洞本來就是很怪的東西。

One more thing.

還有，

Stars are exploding all the time,

經常有恆星在爆炸，

like this one did back in 1987 in our cosmic backyard.

像是這顆 1987 年 在我們星系附近爆炸的恆星。

Black holes are growing all the time.

黑洞一直在變大。

There is a new sky every night.

晚上的星空每天都在變化。

Which means we can't just map the sky one time.

所以每個區域我們不能只觀測一次，

We have to map the sky multiple times.

我們必須反覆觀測。

So in SDSS-V, we're going back to each part of the sky multiple times

所以在 SDSS-V，天空的 每個部分我們都會觀測多次，

in order to see how these objects change over time.

以便觀察這些觀測物 隨著時間的變化。

Because those changes in time encode the physics,

因為這些變化中蘊藏著物理原理，

and they encode how these objects are growing and changing.

以及這些觀測物形成和變化的秘密。

Mow the sky.

望遠鏡反覆掃過天空。

OK, let me just recap.

好，我總結一下。

Global survey, two hemispheres,

全球巡視天空、兩個半球、

five telescopes, 10 spectrographs, millions of objects, mow the sky,

5 個望遠鏡、10 個攝譜儀、 數百萬個觀測物、望遠鏡掃天空、

creative army, robots, yeah.

創造性的軍隊、機器人。

So you're thinking, "Wow.

你可能會猜：「哇！她帶的 一定是個先進的大團隊，

She must have this industrial machine going,

no room for the individual, curious, lone wolf genius," right?

好奇但喜歡單打獨鬥的天才 沒甚麼發展空間。」對吧？

And you'd be 100 percent wrong.

那你就大錯特錯了。

Meet Hanny's Voorwerp.

來認識一下哈尼天體。

Hanny van Arkel was a Dutch schoolteacher

哈尼·馮·阿科爾 曾是一名荷蘭教師，

who was analyzing the public versions of the SDSS data,

她在分析 SDSS 的公開數據時，

when she found this incredibly rare type of object,

發現了這種極罕見的星體，

which is now a subject of major study.

現在成了熱門的研究對象。

She was able to do this

她之所以能夠做到這項發現，

because SDSS, since its beginning and by mandate from the Sloan Foundation,

是因為 SDSS 自成立以來， 由史隆基金會的授權，

has made its data both publicly available

強制將數據向大眾公開，

and usable to a broad range of audiences.

讓廣大的群眾都可以使用。

She's a citizen -- yeah, clap for that.

她只是個普通公民…… 對，是應該鼓掌，

Clap for that.

是應該鼓掌。

(Applause)

（掌聲）

Hanny is a citizen scientist,

哈尼是個草根科學家，

or as I like to call them,

我喜歡把他們這樣的人

"citizen warriors."

稱為「公民戰士」。

And she shows that you don't have to be a fancy astrophysicist to participate.

她的例子顯示，你不需要是個 了不起的天文物理學家也能參與。

You just have to be curious.

你只需要有好奇心。

A few years ago,

幾年前，

my four-year-old asked, "Can moons have moons?"

我四歲的小孩問： 「月亮可以有月亮嗎？」

And I set about to answer this question

從此我開始尋找答案，

because even though many four-year-olds over all of time

因為儘管許多四歲的孩子 都問過這個問題。

have probably asked this question,

many experts, including myself, didn't know the answer.

但許多專家，包括我自己， 也不知道答案。

These are the moons in our solar system that can host hypothetical submoons.

這些是我們太陽系中 理論上可能有子衛星的衛星。

And that just goes to show you that there are so many basic questions

這顯示了，還有很多 基本問題仍待回答。

left to be understood.

And this brings me to the most important point about SDSS.

這就引出了 SDSS 的重點。

Because, yeah, the stars, the galaxies, the black holes, the robots --

沒錯，恆星、星系、黑洞、機器人

that's all super cool.

都超酷的。

But the coolest thing of all

但最酷的是，

is that eensy-weensy creatures on a rubble pile

一個很普通的星系中的 一個普通的恆星，

四周圍繞著一堆石頭， 上面住著一種不起眼的生物，

around a totally average star in a totally average galaxy

can win the battle to understand their world.

他們竟能贏得這場探索宇宙的戰鬥。

Every dot in this video is a galaxy.

這個影片中的每個點都是一個星系。

Every dot.

每一個點喔。

(Cheers) (Applause)

（歡呼）（掌聲）

I'm showing here the number of galaxies

現在展示的是自 1980 年以來，

that astronomers have mapped in large surveys since about 1980.

天文學家在大型巡天過程中 所觀測到的星系數量。

You can see SDSS kick in around Y2K.

你可以看到 SDSS 在 2000 年左右啟動。

If we stay on this line,

如果我們循著這條線走，

we will map every large galaxy in the observable universe by 2060.

2060 年之前我們將繪製出 可觀測宇宙中每一個大星系的圖。

Think about that.

想想看。

Think about it: we've gone from arranging clamshells

在幾千年的時間裡， 我們已經從排列蛤殼，

to general relativity to SDSS in a few thousand years --

到廣義相對論， 再到現在的 SDSS。

and if we hang on 40 more,

如果我們再堅持 40 年，

we can map all the galaxies.

就可以畫出所有星系的圖。

But we have to stay on the line.

但我們必須循著這條線走下去。

Will that be our choice?

我們能做出這樣的選擇嗎？

There are dark forces in this world

這個世界上有一些黑暗勢力，

that will rob our entire species of our right to understand our universe.

它們將剝奪人類了解宇宙的權利。

Don't be afraid of the dark.

不要懼怕黑暗。

Fight back.

要反擊。

Join us.

加入我們的行列。

Thank you.

謝謝大家！

(Applause)

（掌聲）