Your reminder to get the perfect gift this holiday season.

提醒您在這個節日裡獲得完美的禮物。

There might be an object so indestructible, extreme and brutal, that it could kill black holes.

可能有一種物體如此堅不可摧、極端殘酷，以至於可以殺死黑洞。

Gravastars.

重力星

Cosmic soap bubbles filled with pure energy and with a shell made of the weirdest material that's possible in nature.

宇宙肥皂泡充滿了純淨的能量，外殼由自然界中最奇特的材料製成。

What are they?

它們是什麼？

What do they look like?

它們看起來像什麼？

And are they just a theoretical fever dream?

它們只是理論上的狂熱夢想嗎？

Or will they change our understanding of the universe forever?

還是它們將永遠改變我們對宇宙的認識？

Very massive stars die in the most dramatic way possible.

大品質恆星以最戲劇化的方式死亡。

A supernova.

一顆超新星

We've explained this process in detail before.

我們之前已經詳細介紹過這一過程。

But in a nutshell, in less than a second, their cords collapse, crushed under their extreme gravity.

但總而言之，在不到一秒鐘的時間裡，它們的繩索就會崩潰，在極強的重力下被壓斷。

The star's shell rushes in, bounces against the collapsing core, and explodes, shining brighter than whole galaxies.

恆星的外殼衝進來，撞擊坍塌的內核，然後爆炸，發出比整個星系還要耀眼的光芒。

Depending on how massive the star was, there are two possible outcomes.

根據恆星的品質，有兩種可能的結果。

Either the core compresses into a super-dense neutron star, or it kind of breaks reality and collapses into a singularity.

要麼核心壓縮成一顆超密集的中子星，要麼它就會打破現實，坍縮成一個奇點。

An infinitely dense point with no signs or dimensions at all.

一個無限密集的點，沒有任何符號或維度。

A place where the laws of the universe stop making sense, and time and space are reversed.

在這裡，宇宙法則不再有意義，時間和空間被顛倒。

A black hole.

黑洞

Gravastars are a third, even weirder option.

重力星是第三種更奇怪的選擇。

Instead of collapsing into an infinitely dense point, the core is kind of ground down, like a rock pulverized to dust by a cosmic hydraulic press.

核心並沒有坍縮成一個無限緻密的點，而是被磨碎了，就像一塊被宇宙液壓機粉碎成粉末的岩石。

Atoms and particles are crushed so hard that they transform into pure energy.

原子和粒子被狠狠碾碎，轉化為純能量。

A sort of mini-universe, if you want.

如果你願意的話，這就是一個小型宇宙。

And just like our universe, this bubble violently wants to expand and grow.

就像我們的宇宙一樣，這個氣泡劇烈地想要膨脹和成長。

In a fraction of a second, the bubble smashes into the collapsing star around it.

幾分之一秒後，氣泡就撞上了周圍正在坍縮的恆星。

The unspeakable mass of the star collapsing under its own gravity meets the titanic violence of the expanding energy bubble.

恆星在自身引力的作用下坍塌，其品質之大難以言表，而不斷膨脹的能量氣泡則帶來了巨大的衝擊力。

Like an ancient god hammering on its anvil, matter is trapped between an immovable object and an unstoppable force.

就像遠古之神敲打鐵砧一樣，物質被困在一個不可移動的物體和一股不可阻擋的力量之間。

Forging a new kind of material that we've never seen before, but that we know is physically possible.

鍛造一種我們從未見過的新型材料，但我們知道這種材料在物理上是可行的。

And then, it suddenly stops.

然後，它突然停止了。

A gravastar is born.

重力星誕生了

What does it look like?

它看起來像什麼？

Cosmic soap bubbles.

宇宙肥皂泡

Just like black holes, a gravastar can have any mass, but a typical one would be about the size of the London metropolitan area, and as massive as ten suns.

就像黑洞一樣，重力星的品質可以是任何品質，但典型的重力星的大小與倫敦市區差不多，品質相當於 10 個太陽。

The shell of the gravastar is utterly dark, and the coldest thing in the universe.

引力星的外殼漆黑一片，是宇宙中最冷的東西。

Only a billionth of a degree above absolute zero.

只比絕對零度高出十億分之一。

If we look at it in deep infrared, even the cosmic microwave background glows bright in comparison.

如果我們用深紅外光觀測它，即使是宇宙微波背景也會發出耀眼的光芒。

How can anything made of matter be that cold?

由物質構成的東西怎麼會那麼冷？

Don't all atoms jiggle back and forth?

所有原子不都是來回晃動的嗎？

The thing is, the shell's not made out of atoms.

問題是，外殼不是由原子構成的。

It's made from an entirely new, unique, and extreme matter that doesn't have a name yet, and that's at the very limit of what's physically possible in nature.

它是由一種全新的、獨特的、極端的物質製成的，這種物質還沒有名字，而且是自然界中物理可能性的極限。

Actually, the shell is so incredibly thin, that atoms seem truly gigantic next to it.

實際上，外殼薄得令人難以置信，原子在它旁邊顯得非常巨大。

And yet, despite being ultra-thin, because it's been forged by two impossibly extreme forces, the shell is incredibly tight.

然而，儘管超薄，但由於它是由兩種不可能達到的極端力量鍛造而成，外殼的緊密程度令人難以置信。

So tight, that if you wanted to stretch the whole shell by just one meter, you'd need the energy of an entire supernova.

如此緊密，如果你想把整個外殼拉伸一米，就需要整個超新星的能量。

What about the inside?

內部情況如何？

Well, it only gets weirder.

好吧，事情只會變得更奇怪。

The interior of a gravastar is perfectly simple, because it's sort of empty.

重力星的內部結構非常簡單，因為它是空的。

Completely empty.

完全空空如也。

A perfect vacuum without a single atom, particle, or wave.

沒有任何原子、粒子或波的完美真空。

But despite being as empty as it gets, this vacuum is boiling with the most primitive and fundamental kind of energy in the universe.

然而，儘管真空中空空如也，卻沸騰著宇宙中最原始、最基本的能量。

We need a detour to explain how any of this makes sense.

我們需要繞個彎來解釋這一切有什麼意義。

The fundamental nothingness at the core of it all.

一切的核心是根本的虛無。

The inside of a gravastar breaks our brains a bit, because it's a sort of super-condensed nothingness.

重力星的內部讓我們的大腦有點崩潰，因為它是一種超級濃縮的虛無。

What does this even mean?

這到底是什麼意思？

We'll have to simplify and use metaphors to make sense of what scientists measure and calculate.

我們必須化繁為簡，使用隱喻來理解科學家測量和計算的結果。

According to our current understanding of physics, particles like quarks, electrons, photons, and so on, are not really solid objects, but sort of waves in an ocean.

根據我們目前對物理學的理解，夸克、電子、光子等粒子並不是真正的固體物體，而是海洋中的波浪。

In our human world, you can't have waves without water.

在我們人類的世界裡，沒有水就沒有波浪。

And in the smallest world, you also can't have particle waves without some kind of underlying, omnipresent cosmic fluid.

而在最小的世界裡，如果沒有某種潛在的、無所不在的宇宙流體，也就不可能有粒子波。

This fluid is the vacuum, what we perceive as nothingness.

這種液體就是真空，也就是我們眼中的虛無。

It's the fundamental ocean at the bottom of reality.

這是現實底層的基本海洋。

The waves of this vacuum ocean are the particles that make up you and everything else.

真空海洋的波浪就是構成你和其他一切的粒子。

But even when there are no waves or particles traveling through it, the fluid is still there.

但即使沒有波或粒子通過，流體仍然存在。

And, like any fluid we know, it has inherent energy.

而且，就像我們所知的任何流體一樣，它具有固有的能量。

Vacuum fluid is everywhere in the universe.

真空流體在宇宙中無處不在。

The room you're in is 99.98% vacuum between the air particles bouncing around.

你所處的房間裡，空氣微粒之間 99.98% 是真空狀態。

Between the trillions of particles making up your cells, there's vacuum.

在構成細胞的數以萬億計的微粒之間，存在著真空。

But it's different inside a gravassar.

但在 gravassar 內就不一樣了。

When our star collapsed and condensed so violently, it was as if the universe took a cosmic pump and compressed as much vacuum fluid as physics allows.

當我們的恆星如此劇烈地坍塌和凝結時，就好像宇宙用一個宇宙泵，在物理學允許的範圍內壓縮了儘可能多的真空流體。

Into a kind of super-dense nothingness.

變成一種超密集的虛無。

As said before, even without any waves, the nothingness vacuum ocean of the universe has energy.

如前所述，即使沒有任何波浪，宇宙的虛無真空海洋也具有能量。

But the super-dense vacuum inside a gravassar has almost a billion, trillion, trillion, trillion times more energy per cubic centimeter than the vacuum outside the star.

但是重力星內部的超高密度真空每立方厘米的能量幾乎是恆星外部真空的十億、萬億、萬億、萬億倍。

This is an unbelievable amount of energy and mass in a tiny space.

在如此狹小的空間內，能量和品質之大令人難以置信。

Just like, you may have guessed it, black holes.

就像你可能已經猜到的，黑洞。

This intensely compressed vacuum ocean can't be compressed any further.

這個高度壓縮的真空海洋已經無法再壓縮了。

It's at the absolute physical limit of anything that could be squeezed together without breaking physics like black holes do.

它處於任何東西的絕對物理極限，可以被擠壓在一起而不會像黑洞那樣破壞物理學。

The ocean would love to stop being so tight.

海洋也希望不再那麼緊繃。

It wants to stretch out and flow back into the ocean that surrounds the star.

它想伸展開來，流回環繞恆星的海洋。

But it's trapped in the safest prison possible.

但它被困在最安全的監獄裡。

The shell, which itself is right at the edge of the physical limit of any material possible.

外殼本身就處於任何可能材料的物理極限邊緣。

An eternal stalemate between two limits of the universe.

宇宙兩個極限之間永恆的僵局。

Let's leave this world of metaphors and get back to our world that feels more real.

讓我們離開這個充滿隱喻的世界，回到我們感覺更真實的世界。

In our world, gravastars are perfectly black eternal objects with borderline insane amounts of mass.

在我們的世界裡，引力星是完美的黑色永恆物體，其品質近乎瘋狂。

Because they're so cold, dark, and massive, from the outside, gravastars look and behave exactly like black holes.

由於它們是如此寒冷、黑暗和巨大，從外表上看，引力星的外觀和行為都與黑洞一模一樣。

Both massively curve space around them and create all the fun effects we love black holes for.

兩者都會使其周圍的空間發生巨大的彎曲，併產生我們所喜愛的黑洞的所有有趣效果。

From trapping mass and light in accretion disks or slowing down time as you get closer.

從在吸積盤中捕獲品質和光，到隨著距離的接近而減慢時間。

For details, we've made one or two videos on black holes before.

關於細節，我們以前製作過一兩個關於黑洞的視頻。

If you fell into a gravastar, you'd be extremely dead before you even hit the surface.

如果你掉進重力星裡，還沒到地面就已經死得不能再死了。

Ripped apart and ground down by the gravitational forces.

被引力撕裂、磨碎。

And once your scattered remains touch the shell, the atoms you were once made of would probably break down and dissolve completely.

一旦你散落的殘骸接觸到外殼，你曾經由之構成的原子很可能就會分解並完全溶解。

Only to be converted into the vacuum energy of the interior.

只能轉化為內部的真空能量。

Making the gravastar an infinitesimal bit bigger and an infinitesimal bit more massive.

使重力星的體積增大無限小，品質增大無限大。

Okay, this was fun and all, but what exactly is the point?

好吧，這很有趣，但到底有什麼意義呢？

Isn't this just another video of wild scientific speculation just for the sake of it?

這不又是一段為了科學而科學的胡亂猜測嗎？

The point.

重點是

Black holes were suggested more than a century ago as an abstract solution to equations of gravity.

一個多世紀前，黑洞作為萬有引力方程的抽象解決方案被提出。

For more than 50 years, they were considered mathematically valid, but too absurd to be real.

50 多年來，人們一直認為它們在數學上是正確的，但太荒謬而不真實。

Few believed they actually existed.

很少有人相信它們真的存在。

But scientists kept working on paper and looking at weird things.

但是，科學家們一直在紙上工作，研究一些奇怪的東西。

And then we saw stars being thrown around by invisible titans.

然後，我們看到星星被無形的巨人拋來拋去。

We saw light stretching around invisible gaps in the sky.

我們看到光線在天空無形的縫隙中延伸。

And as our technology and theories improved, we even sort of took a picture of them.

隨著技術和理論的進步，我們甚至給它們拍了照片。

We have evidence for them, and they fit our theories.

我們有證據，它們符合我們的理論。

And nowadays, it's kind of common sense to accept them as real.

如今，接受它們是真實的，已經成為一種常識。

Black holes are extremely elegant and fascinating.

黑洞極其優雅迷人。

But they also created a lot of questions that have traumatized physicists for decades.

但它們也產生了許多問題，幾十年來一直困擾著物理學家。

Singularities literally break our best understanding of physics.

奇點從字面上打破了我們對物理學的最佳理解。

They seem to delete information which shouldn't be possible.

他們似乎刪除了本不可能刪除的資訊。

Gravastars are a relatively new idea without any of those problems.

重力星是一個相對較新的想法，不存在這些問題。

They don't need singularities that break physics or delete information.

它們不需要破壞物理學或刪除資訊的奇點。

They solve the puzzles of black holes.

他們解開了黑洞之謎。

But they too create new problems.

但它們也會帶來新的問題。

Like weird exotic matter for their incredibly cold and tight shell.

就像奇怪的外來物質一樣，它們的外殼無比冰冷而嚴密。

Super dense nothing to make a supermassive empty core.

超大密度的空心什麼都沒有。

But just like black holes, they do work on paper and fit what we see in the sky.

但就像黑洞一樣，它們在紙面上確實有效，也符合我們在天空中看到的情況。

So, are they real?

那麼，它們是真的嗎？

And will we ever know?

我們會知道嗎？

Actually, there is a way to find out.

其實，有一種方法可以找出答案。

Black holes have an event horizon, while gravastars have a physical shell made of matter.

黑洞有一個事件視界，而引力星則有一個由物質構成的物理外殼。

Which means that they behave very differently when they smash into each other.

這意味著，當它們相互撞擊時，它們的行為會截然不同。

The collision of two objects, as massive as they are, creates huge amounts of gravitational waves.

兩個巨大天體的碰撞會產生巨大的引力波。

Ripples in space-time that travel at the speed of light.

以光速傳播的時空波紋。

You can think of them as the music of cosmic cataclysms.

你可以把它們想象成宇宙災難的音樂。

The collision of two black holes should sound like a bass drum.

兩個黑洞碰撞的聲音應該像低音鼓。

A deep thumb that stops quickly.

拇指深陷，迅速停止。

But two gravastars colliding should sound like a gong, leaving subtle echoes behind.

但是，兩顆重力星碰撞的聲音應該像鑼聲一樣，留下微妙的回聲。

Scientists are listening for these echoes in the music of the cosmos.

科學家們正在聆聽宇宙音樂中的這些回聲。

Unfortunately, black holes and gravastars are surrounded by such strong gravity that it swamps most of the music.

不幸的是，黑洞和重力星被強大的引力包圍，淹沒了大部分音樂。

It's like trying to tell two instruments apart through a thick wall of concrete.

這就好比隔著厚厚的水泥牆分辨兩件樂器。

You need very sharp technology for that.

這需要非常先進的技術。

While we've made incredible progress in the last few years, we're not quite there yet.

雖然我們在過去幾年中取得了令人難以置信的進步，但我們還沒有完全達到目標。

So this is where we'll end this story.

故事到這裡就結束了。

Gravastars have the potential to answer some of the biggest problems in physics.

引力星有可能解答物理學中的一些重大問題。

Or they're just another idea for our discard pile.

或者，它們只是我們丟棄的另一個想法。

But this is why we do science.

但這正是我們從事科學研究的原因。

To learn that everything is different to the way we thought it is.

瞭解到一切都與我們想象的不同。

Until the day we truly understand the nature of reality.

直到有一天，我們真正理解了現實的本質。

Discovery is an ongoing process.

發現是一個持續的過程。

What you know today might be proven wrong tomorrow.

你今天所知道的也許明天就會被證明是錯誤的。

To evolve your worldview, you have to keep learning.

要發展自己的世界觀，就必須不斷學習。

And our partner Brilliant makes it easy to learn something new every day.

我們的合作伙伴 Brilliant 讓您每天都能輕鬆學到新知識。

Brilliant is designed to make you a better thinker and problem solver.

Brilliant 的目的是讓你成為一個更好的思考者和問題解決者。

With thousands of interactive, bite-sized lessons on just about anything you may be curious about.

數以千計的互動式小課程，內容涉及你可能好奇的任何事情。

From maths and science to data analysis, programming, even the physics of black holes.

從數學和科學到數據分析、編程，甚至黑洞物理學。

In fact, we've partnered with Brilliant on a series of courses to expand your understanding of our universe.

事實上，我們已經與 Brilliant 合作開設了一系列課程，以拓展您對我們宇宙的瞭解。

Each one is like a one-on-one version of a Kurzgesagt video that dives deeper into the topics of some of our most popular videos like Rabies, Supernova, and, you guessed it, black holes.

每個視頻都像是一對一版的 Kurzgesagt 視頻，深入探討我們最受歡迎的一些視頻的主題，如狂犬病、超新星和黑洞，你猜對了。

You'll get hands-on with an interactive model of a black hole to see how its mass affects its surroundings.

您將親手操作黑洞的互動模型，瞭解黑洞的品質如何影響周圍環境。

You'll also experience what it's like to be an astronaut floating dangerously close to one of these celestial behemoths.

您還將體驗到太空人漂浮在這些天體巨獸附近的危險感覺。

Brilliant has a huge library of other lessons to explore with new lessons added each month.

Brilliant 還有一個龐大的課程庫，每月都有新的課程加入，供您探索。

And you can get started whenever, wherever, right from whatever device you'd like.

無論何時何地，您都可以通過任何設備開始使用。

Spending just a few minutes learning on Brilliant each day helps you see the world in new ways, build powerful problem-solving skills, and end every day a little smarter.

每天只需花幾分鐘時間學習 Brilliant，就能幫助你以新的方式看待世界，培養強大的解決問題的能力，並在每天結束時變得更聰明一些。

To get hands-on with Kurzgesagt lessons and explore everything Brilliant has to offer, start your free 30-day trial by signing up at brilliant.org.

要親身體驗 Kurzgesagt 課程並探索 Brilliant 提供的一切，請在 brilliant.org 註冊，開始為期 30 天的免費試用。

There's even an extra perk for Kurzgesagt viewers.

Kurzgesagt 的觀眾甚至還有額外的福利。

Anyone signing up through our link will get 20% off an annual membership once their trial ends.

試用期結束後，通過我們的鏈接註冊的用戶可享受年度會籍八折優惠。

The 12,025 human-era calendar is here, and it's our statement about humanity. 12,000 years ago, our ancestors first started working together on a larger scale.

12025 年人類時代的日曆已經到來，它是我們對人類的宣言。12000 年前，我們的祖先第一次開始大規模合作。

This ability to collaborate and share knowledge is one of the very things that makes us human.

這種合作和分享知識的能力正是我們之所以為人的原因之一。

When our ancestors came together to build something truly great for the first time, they also created the foundation of civilization and what it means to be human today.

當我們的祖先聚集在一起，第一次創造出真正偉大的東西時，他們也創造了文明的基礎和今天作為人類的意義。

The stories we tell and metaphors we share shape our perception of the world.

我們講述的故事和分享的隱喻塑造了我們對世界的認知。

That's why the human-era calendar uses a new year zero.

這就是人類時代的日曆使用新的零年的原因。

It adds 10,000 years to the common era system to signify the true beginning of humanity.

它在公元紀年系統的基礎上增加了一萬年，以表示人類的真正開始。

Each year, we release a new edition of this very special passion project.

每年，我們都會推出這個非常特別的激情項目的新版本。

This time, it chronicles humanity's greatest journey that took our ancestors from East Africa all across the planet.

這一次，它記錄了人類最偉大的旅程，我們的祖先從東非出發，穿越整個地球。

Make 12,025 truly special and join us in celebrating this Thai modern tradition.

與我們一起慶祝這一泰國現代傳統，讓 12 025 日真正與眾不同。

The calendar is available exclusively on our shop.

該日曆僅在我們的商店出售。

We've also prepared a few bundles with some of our favorite products.

我們還準備了一些我們最喜歡的產品捆綁包。

Get your piece of shared history and an essential part of Kurzgesagt.

這將是一段共同的歷史，也是 Kurzgesagt 的重要組成部分。