No blue bats, no blue squirrels, no blue dogs.

沒有藍色的蝙蝠、藍色的松鼠、藍色的狗。

Even blue whales aren't that blue.

甚至藍鯨也沒有那麼藍。

Animals come in pretty much every color, but blue seems to be the rarest.

動物有各種顏色，但藍色感覺是最稀有的。

What's cool, though, is when we do find a blue animal, they're awesome looking.

不過很酷的是，藍色的動物都長的非常好看。

Nature doesn't do halfway with blue.

大自然在製作藍色的時候沒有偷懶。

To understand why this is, we're gonna journey through evolution, chemistry, and some very cool physics.

為了理解這背後的原因，我們將進行一次演化、化學和一些非常酷的物理學之旅。

But, first, we're gonna need to understand why animals are any color at all,

但首先，我們需要理解為什麼動物會有各種不同的顏色，

and to do that, we need to go look at some butterflies, because butterflies are awesome.

為了理解這一點，我們需要去觀察一些蝴蝶，因為蝴蝶真的很棒。

And if you don't think so, you're wrong.

如果不這麼覺得，你就錯了。

This is Bob Robbins.

這位是 Bob Robbins。

He's curator of Lepidoptera at the National Museum of Natural History in Washington D.C.

他是華盛頓特區國家自然歷史博物館的鱗翅目動物學館長。

Butterflies are awesome.

蝴蝶超讚的。

Make no mistake about it.

毫無疑問。

They're a group of moths that evolved to be active during the day,

它們是一群進化為在白天活動的蛾類，

and if you're active during the day, that means you have an advantage; you can use light to communicate.

如果你在白天活動，這意味著你具有優勢；你可以利用光來進行溝通。

You probably realize this, but out of all insects, butterflies display the brightest and most detailed patterns.

你可能已經意識到了，但在所有昆蟲中，蝴蝶展示出最明亮和最詳細的圖案。

And there's a good reason for that:

這其中有一個很好的原因：

The colors in butterfly wings deliver messages, like "I'm toxic", or "I'm a male and this is my territory",

蝴蝶翅膀上的顏色傳遞信息，比如「我有毒」或「我是公蝴蝶，這是我的領土」，

but not all butterfly colors are created equal.

但並非所有蝴蝶的顏色都是相等的。

If we zoom way in on a butterfly wing, we see the colors come from tiny scales.

如果我們對蝴蝶翅膀進行放大觀察，就會看到這些顏色來自微小的鱗片。

It's actually how moths and butterflies get their scientific name.

這其實就是蛾和蝴蝶得到它們的學名的方式。

Oranges, reds, yellows browns… those scales all contain pigments, organic molecules that absorb every color except what we see.

橙色、紅色、黃色、棕色... 這些鱗片都包含著顏料，有機分子吸收除我們所看到的顏色以外的每種顏色。

Black scales absorb all colors.

黑色的鱗片吸收所有顏色。

Animals, from butterflies to birds to you and me, don't make these pigments from scratch, they're made from ingredients in our diet.

動物，從蝴蝶到鳥類再到我們，不會從頭開始製造這些顏料，它們是由我們飲食中的成分製成的。

You might know this thanks to flamingos.

你可能因紅鶴而知道這件事。

They're born gray, but turn pink thanks to pigments called carotenoids in crustaceans they eat.

它們出生時是灰色的，但因為它們食用的甲殼類動物中含有的類胡蘿蔔素顏料而變成粉紅色。

So when it comes to these colors, you are what you eat.

因此，當涉及到這些顏色時，可以說你是你所吃的東西。

But not so for blue.

但藍色並不是這樣。

Blue is different.

藍色不一樣。

If you move the camera, if you can see that the color changes as you move the camera.

如果你移動相機，你可以看到隨著相機的移動，顏色也會改變。

It does. It's like a hologram thing.

確實如此，它就像一個全息影像一樣。

Yeah, and this is because there's no blue pigment in these butterflies

是的，這是因為這些蝴蝶中沒有藍色的顏料。

Wait… so they're blue, but they're not really blue?

等等，所以他們是藍色的，但又不是真的藍色？

That's correct! Yes.

沒錯！

You're lying to me, butterflies!

蝴蝶們，你們騙我！

These are Blue Morpho butterflies, maybe the prettiest butterflies of all.

這些是藍色變形蝴蝶，也許世界上數一數二漂亮的蝴蝶。

I mean… they did make it the butterfly emoji.

我是說...它們漂亮到有表情符號。

The blue color isn't from a pigment.

他們的藍色並不是來自顏料。

The blue comes from the shape of the wing scale itself, and when I learned how this works, it kinda blew my mind.

這種藍色來自翅膀鱗片本身的形狀，當我學到這是如何運作的時候，感到相當驚訝。

If we zoom way in on a blue wing scale, we see these little ridges.

如果我們對藍色翅膀鱗片進行放大觀察，我們會看到這些小的脊紋。

We slice across the scale and look closer, we see those ridges are shaped like tiny Christmas trees.

如果我們切割穿過這個鱗片並更仔細地觀察，我們會看到這些脊紋的形狀就像小聖誕樹一樣。

The arrangement of the branches is what gives Morpho wings their blue color.

分支的排列方式決定了藍變形蝴蝶翅膀的顏色。

When light comes in, some bounces off the top surface.

當光線進入時，一些光線會反射出來，擊中翅膀鱗片的最外層。

But some light passes into the layer and reflects off the bottom surface.

但有些光線穿透到了這一層，然後反射到底層。

For most colors of light, waves reflecting from the top and bottom will be out of phase,

對於大多數光的顏色，從頂部和底部反射的波將處於不同相位，

they'll be canceled out, and that light is removed.

它們將被抵消，並且那些光被消除。

But blue light has just the right wavelength; the reflected light waves are in sync, and that color makes it to our eye.

但藍光具有正確的波長；反射的光波同步，這種顏色進入我們的眼睛。

This hall of mirrors only lets blue light escape.

這個鏡子之廳只允許藍光逃逸。

There's even a pigment at the base that absorbs stray red and green light to make the blue even more pure.

甚至在基部有一種顏料，吸收雜散的紅光和綠光，使藍色更純淨。

That's how we get this awesome iridescent blue.

這就是我們得到這種令人驚嘆的彩虹般的藍色的方式。

The microscopic structure of the wing itself.

這是由翅膀本身的微觀結構所決定的。

All of this happens because of the way light bends when it moves from air into another material.

所有這些都是因為光線從空氣進入另一種材料時彎曲的方式。

So if we fill all those tiny gaps with something other than air, like alcohol, the blue disappears.

因此，如果我們用除了空氣以外的材料，比如酒精，來填滿所有這些微小的間隙，藍色就會消失。

Technically, this "changes the index of refraction", but in plain English, that means blue light is no longer bent the right way.

技術上，這種情況下會「改變折射率」，但用簡單的詞語來說，就是藍光不再以正確的方式彎曲。

The microscopic light filter is broken until the alcohol evaporates, and the color returns.

微觀級的光濾鏡在酒精蒸發之前被破壞，然後顏色會恢復。

But these butterflies live in the rainforest.

但這些蝴蝶生活在熱帶雨林中。

You think they'd lose their color any time they got wet, right?

你認為它們在濕了的時候會失去顏色，對

Well, watch this.

看看這個。

These wing scales are made of a material that's naturally water-resistant.

這些翅膀鱗片由一種天然具有防水性的材料製成。

They stay blue in any weather.

無論天氣如何，它們的顏色都保持藍色。

So what about this blue jay feather?

那麼這根藍松鳥羽毛呢？

If we look through it, the color completely disappears. No blue pigment.

如果我們透過它看，顏色完全消失了，沒有藍色的顏料。

Each feather bristle contains light-scattering microscopic beads, spaced so everything but blue light is canceled out.

每根羽毛的刷子都包含著微觀的散射光微粒，它們的間距使除藍光以外的所有光都被抵消掉。

Unlike the highly-ordered structures we find in butterfly wings, these feather structures are more messy, like a foam,

不同於蝴蝶翅膀上的高度有序結構，這些羽毛結構更加雜亂，就像泡沫一樣，

so instead of changing as we move, the color's more even from every direction.

因此，顏色不會隨著我們移動而改變，而是從每個方向看更加均勻。

Peacock tail feathers?

孔雀尾羽？

Again, it's the shape of the feather, not pigment.

再次強調，這是由於羽毛的形狀而不是色素。

But the light-reflecting structures here are more ordered, like a crystal, so it's brighter from certain angles.

但是這裡的反射光結構更有秩序，就像水晶一樣，因此在特定角度下更加明亮。

There's even a monkey–WHOA, let's keep this PG!!–

甚至還有一隻猴子——哇，讓我們保持這個影片適合所有年齡觀眾吧——

even that color is made by the adding and subtracting of light waves thanks to structures in the skin,

甚至這種顏色也是由於皮膚中的結構對光波的添加和減少而形成的，

and yes, even your blue eyes, are colored by structures, not pigments.

是的，甚至你的藍色眼睛也是由結構而不是色素賦予顏色的。

Outside of the ocean, almost exclusively, the bluest living things make their colors with microscopic structures, and each one's a little different.

除了海洋之外，幾乎所有最藍的生物都是通過微觀結構來製造它們的顏色，而且每一個都略有不同。

No vertebrate, not a single bird or mammal or reptile that we know of, makes a blue pigment on its body.

根據我們所知，沒有一種脊椎動物，包括鳥類、哺乳動物或爬行動物，會在其身體上生成藍色色素。

In fact, there's only one known butterfly that has cracked the code for making a true blue pigment.

事實上，只有一種已知的蝴蝶破解了生成真正藍色色素的密碼。

Blue as a pigment in nature is incredibly rare.

自然界中的藍色色素極為罕見。

But there's one exception so far that we know about, and these are over here called the olivewings.

但就目前我們所知，有一個例外，那就是這些被稱為橄欖蛺蝶的蝴蝶。

They have evolved a blue pigment.

它們已經進化出了一種藍色色素。

And they're not very common and we don't know much about them, and I don't know of any other blue pigment.

它們並不常見，我們對它們了解有限，而我也不知道其他的藍色色素存在。

That's a really special butterfly.

這是一種非常特別的蝴蝶。

But why is almost all of nature's blue made from structures and not pigments like everything else?

但為什麼自然界中幾乎所有的藍色都是由結構而不是像其他顏色一樣由色素形成的呢？

I've asked this question to several scientists that study color, and here's their best theory so far:

我向幾位研究色彩的科學家提出了這個問題，以下是他們迄今為止的最佳理論：

At some point way back in time, birds and butterflies evolved the ability to see blue light.

在遙遠的過去某個時刻，鳥類和蝴蝶進化出了能夠看到藍光的能力。

But they hadn't yet evolved a way to paint their bodies that color.

但他們還沒有進化出一種方法來將自己的身體塗成那種顏色。

But if they could, it'd be like going from early Beatles to Sgt. Pepper's Beatles.

但如果他們能夠這樣做，就好比從早期的披頭四轉變為《Sgt. Pepper's》時期的披頭四。

It meant new opportunities for communicating and survival.

這意味著新的交流和生存機會。

Creating some blue pigment–out of the blue–would have required inventing new chemistry, and there was no way to just add that recipe to their genes.

創造一些藍色色素——突然之間——需要發明新的化學物質，而無法將這個配方直接添加到它們的基因中。

It was much easier for evolution to change the shape of their bodies, ever so slightly, at the most microscopic level, and create blue using physics instead.

進化通過微小地、在最微觀的水平上改變身體的形狀，並使用物理學而不是化學來創造藍色，要容易得多。

They solved a biology problem with engineering.

他們用工程學的方法解決了一個生物學問題。

What I love about this is these colors have fascinated curious people for hundreds of years.

我喜歡這一點的是，這些顏色已經吸引著好奇的人們數百年了。

After looking at peacock feathers through one of the first microscopes back in the 1600's

自17世紀早期透過其中一個最早期的顯微鏡觀察孔雀羽毛後，

Robert Hooke wrote, "These colours are onely fantastical ones."

羅伯特·胡克（Robert Hooke）在觀察後寫道："這些顏色只是幻想的。"

Even Isaac Newton noticed there was something unusual about these blues, and scientists have been studying it ever since.

甚至艾薩克·牛頓（Isaac Newton）也注意到這些藍色有些不尋常，自那時以來，科學家一直在研究它。

Not only because the science is interesting, but because it's beautiful.

不僅因為這個科學問題很有趣，而且因為它很美麗。

Thanks for watching, and stay curious.

感謝觀看，保持好奇心。