Sheila Patek: Measuring the fastest animal on earth

137,745 views ・ 2007-05-17

TED


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譯者: Meg Lee 審譯者: Joan Liu
00:25
If you'd like to learn how to play the lobster, we have some here.
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如果你想要學習如何扮演龍蝦,我們這裡準備了一些。
00:28
And that's not a joke, we really do.
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這不是在開玩笑的,我們真的準備了。
00:30
So come up afterwards and I'll show you how to play a lobster.
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所以演講結束之後各位可以到台前來,我會示範如何扮演龍蝦。
00:33
So, actually, I started working on what's called the mantis shrimp
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好的,實際上,我大約從幾年前
00:37
a few years ago because they make sound.
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開始研究所謂的螳螂蝦,因為他們會製造聲音。
00:40
This is a recording I made of a mantis shrimp
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這是我曾經錄製的螳螂蝦的聲音,
00:42
that's found off the coast of California.
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就在加州沿海。
00:55
And while that's an absolutely fascinating sound,
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雖然這絕對是一種令人徹底驚嘆的聲音,
00:58
it actually turns out to be a very difficult project.
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實際要去研究卻非常困難。
01:01
And while I was struggling to figure out how and why mantis shrimp,
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而當我掙扎著想要弄清楚螳螂蝦,或稱蝦蛄,
01:06
or stomatopods, make sound, I started to think about their appendages.
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到底怎麼發出聲音,我開始注意到牠們的附屬枝
01:10
And mantis shrimp are called "mantis shrimp" after the praying mantises,
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螳螂蝦這名字是由螳螂而來
01:13
which also have a fast feeding appendage. And I started to think,
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螳螂也有類似這樣可以快速移動捕食的前附屬枝。所以我開始想
01:17
well, maybe it will be interesting, while listening to their sounds,
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邊聽著牠們的聲音,我想著,這可能會非常有趣
01:20
to figure out how these animals generate very fast feeding strikes.
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要是我可以弄清楚這些動物怎麼產生這樣非常快速的出擊行動。
01:23
And so today I'll talk about the extreme stomatopod strike,
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所以今天我要談論的,就是關於螳螂蝦這樣急速的出擊捕食行為。
01:27
work that I've done in collaboration with Wyatt Korff and Roy Caldwell.
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這是我和Wyatt Korff和Roy Caldwell一起進行的研究。
01:30
So, mantis shrimp come in two varieties:
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好的,螳螂蝦可以分成兩種類型。
01:33
there are spearers and smashers.
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穿刺型和粉碎型。
01:35
And this is a spearing mantis shrimp, or stomatopod.
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這個是穿刺型的螳螂蝦,或蝦蛄
01:38
And he lives in the sand, and he catches things that go by overhead.
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牠住在沙地裡,捕捉那些從牠頭上經過的動物。
01:43
So, a quick strike like that. And if we slow it down a bit,
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就像是這樣快速的出擊,所以如果我們把這個速度放慢
01:48
this is the mantis shrimp -- the same species --
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這是螳螂蝦,同樣的物種
01:50
recorded at 1,000 frames a second,
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用每秒一千幅的速度錄製
01:52
played back at 15 frames per second.
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用每秒15幅的慢速播放
01:54
And you can see it's just a really spectacular extension of the limbs,
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你們可以看到,那只是個非常令人嘆為觀止的上臂延伸
02:00
exploding upward to actually just catch
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爆炸性地向上,然後真的就接住
02:03
a dead piece of shrimp that I had offered it.
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我為牠準備的蝦子碎片
02:05
Now, the other type of mantis shrimp is the smasher stomatopod,
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現在,另外一種螳螂蝦則是粉碎型蝦蛄
02:10
and these guys open up snails for a living.
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這些傢伙靠著拆開螺維生。
02:13
And so this guy gets the snail all set up and gives it a good whack.
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所以這個傢伙,把螺擺好,接著給了牠一個重擊。
02:18
(Laughter)
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(聽眾大笑)
02:19
So, I'll play it one more time.
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我現在把這段影片再播一次
02:21
He wiggles it in place, tugs it with his nose, and smash.
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牠把螺扭動到定點,用鼻子推,然後將之粉碎。
02:25
And a few smashes later, the snail is broken open, and he's got a good dinner.
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幾次重擊之後,螺的殼被打開,他於是享用豐盛晚餐。
02:32
So, the smasher raptorial appendage can stab with a point at the end,
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所以粉碎型蝦蛄可靠前枝末端穿刺。
02:36
or it can smash with the heel.
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或著利用後跟粉碎。
02:38
And today I'll talk about the smashing type of strike.
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今天我要談論的,主要是關於像這樣粉碎性的攻擊。
02:41
And so the first question that came to mind was,
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所以我當時第一個想到的問題是,
02:43
well, how fast does this limb move?
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恩,那麼牠的枝節可以移動的多快?
02:46
Because it's moving pretty darn fast on that video.
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因為在那個影片中,它們移動得可還真快。
02:49
And I immediately came upon a problem.
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接著我立刻遇到一個難題,
02:52
Every single high-speed video system in the biology department
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柏克萊大學生物系裡頭每一台高速錄影機
02:55
at Berkeley wasn't fast enough to catch this movement.
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都沒有快到可以捕捉這個動作
02:59
We simply couldn't capture it on video.
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我們基本上沒辦法錄到這個行為。
03:01
And so this had me stymied for quite a long period of time.
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這個問題,阻礙了我的研究很長一段時間。
03:04
And then a BBC crew came cruising through the biology department,
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接著某天,有個英國廣播公司的工作人員來訪我們生物系,
03:07
looking for a story to do about new technologies in biology.
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找尋適合拍攝「高科技在生物學的應用」這樣主題的故事。
03:12
And so we struck up a deal.
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所以我們談了一個合作案,
03:14
I said, "Well, if you guys rent the high-speed video system
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我說:「如果你們把可以捕捉到這些行為的
03:16
that could capture these movements,
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高速錄影系統租給我們,
03:18
you guys can film us collecting the data."
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你們可以側錄我們收集資料的過程。」
03:21
And believe it or not, they went for it. (Laughter)
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相不相信?!他們竟然同意了。
03:23
So we got this incredible video system. It's very new technology --
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所以我們得到了這個非常了不起的錄影系統。是非常新的技術,
03:27
it just came out about a year ago --
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大約一年前才上市。
03:29
that allows you to film at extremely high speeds in low light.
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它可以讓你在非常微弱的光線中,以極高的速度來錄影。
03:34
And low light is a critical issue with filming animals,
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微弱的光線經常是錄製動物行為的關鍵問題,
03:36
because if it's too high, you fry them. (Laughter)
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因為如果溫度太高,你會炸了這些動物。
03:39
So this is a mantis shrimp. There are the eyes up here,
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這是螳螂蝦,牠們的眼睛在上面,
03:44
and there's that raptorial appendage, and there's the heel.
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這就是掠食的副肢,這是足跟
03:47
And that thing's going to swing around and smash the snail.
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那就是會來回擺動粉碎螺著東西
03:50
And the snail's wired to a stick,
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這是一個附著在一個棒子上的螺
03:51
so he's a little bit easier to set up the shot. And -- yeah.
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所以他比較容易架設錄影機,接著,對。
03:55
(Laughter)
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(聽眾笑聲)
03:57
I hope there aren't any snail rights activists around here.
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我希望這裡沒有推廣「螺權」的激進份子,
04:00
(Laughter)
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(聽眾笑聲)
04:02
So this was filmed at 5,000 frames per second,
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這是以每秒五千畫幅拍攝的短片
04:07
and I'm playing it back at 15. And so this is slowed down 333 times.
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而我是用每秒十五畫幅的速度在播放。所以這大概是333倍慢速。
04:12
And as you'll notice, it's still pretty gosh darn fast
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你們會注意到,牠的動作其實還是驚人的快速。
04:15
slowed down 333 times. It's an incredibly powerful movement.
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即使放慢了333倍速。這一就是個非常強而有力的動作。
04:19
The whole limb extends out. The body flexes backwards --
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整個肢體往外延伸;身體向後彎曲,
04:22
just a spectacular movement.
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相當引人入勝的一個動作。
04:25
And so what we did is, we took a look at these videos,
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所以我們當時就是研究這些影片,
04:27
and we measured how fast the limb was moving
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測量這枝節移動的速度有多快
04:29
to get back to that original question.
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以回答我們最開始問的問題。
04:31
And we were in for our first surprise.
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而我們面對了我們的第一個驚喜。
04:34
So what we calculated was that the limbs were moving
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當時我們計算的結果,這些枝節是以
04:37
at the peak speed ranging from 10 meters per second
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可高達每秒十公尺
04:39
all the way up to 23 meters per second.
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至每秒二十三公尺的速度在運動
04:41
And for those of you who prefer miles per hour,
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而對現場那些比較熟悉以時速為單位的聽眾
04:43
that's over 45 miles per hour in water. And this is really darn fast.
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那換算起來便是以超過每小時七十公里的速度在移動。這是非常非常快的速度。
04:48
In fact, it's so fast we were able to add a new point
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事實上,這速度快到我們得新增加一個點
04:52
on the extreme animal movement spectrum.
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在動物急速運動的座標上。
04:55
And mantis shrimp are officially the fastest measured feeding strike
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螳螂蝦,正式成為,擁有最快掠食攻擊速度的物種
04:58
of any animal system. So our first surprise.
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在任何被量測過的動物系統中。所以,這是我們的第一個驚喜。
05:02
(Applause)
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(聽眾鼓掌)
05:03
So that was really cool and very unexpected.
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剛剛那個發現是出乎意料之外且非常厲害的。
05:06
So, you might be wondering, well, how do they do it?
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那麼你接著可能會想,恩,那牠們是怎麼辦到的呢?
05:09
And actually, this work was done in the 1960s
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事實上,這個問題在1960年就被研究過了
05:12
by a famous biologist named Malcolm Burrows.
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是一位非常有名的生物學家Malcolm Burrows
05:14
And what he showed in mantis shrimp is that they use
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他當時在螳螂蝦上面發現
05:17
what's called a "catch mechanism," or "click mechanism."
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牠們是使用一種叫做捕捉或點擊的機制。
05:20
And what this basically consists of is a large muscle
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這基本上包含了使用一塊大肌
05:24
that takes a good long time to contract,
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花相當長的時間收縮
05:26
and a latch that prevents anything from moving.
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還要一個插銷防止任何部位移動
05:29
So the muscle contracts, and nothing happens.
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所以只有那塊肌肉收縮,除此之外沒有其他事情發生。
05:31
And once the muscle's contracted completely, everything's stored up --
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當這塊肌肉完全收縮,所有的能量都儲存好
05:34
the latch flies upward, and you've got the movement.
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直到這個銷往上飛,這個快速的動作就出現了。
05:38
And that's basically what's called a "power amplification system."
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這個基本上稱作能量加成系統。
05:41
It takes a long time for the muscle to contract,
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肌肉花很長的時間收縮,
05:43
and a very short time for the limb to fly out.
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而枝節花了很短的時間飛出
05:45
And so I thought that this was sort of the end of the story.
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所以當時我想這大概就是故事的結局。
05:48
This was how mantis shrimps make these very fast strikes.
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這就是螳螂蝦如何快速的出擊。
05:52
But then I took a trip to the National Museum of Natural History.
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可是,我接著去造訪國家自然史博物館。
05:56
And if any of you ever have a chance,
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如果你們任何一位有機會,
05:58
backstage of the National Museum of Natural History
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去看看國家自然史博物館的後台
06:00
is one of the world's best collections of preserved mantis shrimp. And what --
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那是全世界保存螳螂蝦標本最完整個地方,然後
06:04
(Laughter)
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(聽眾笑聲)
06:05
this is serious business for me.
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這對我來說是非常嚴肅的事情。
06:07
(Laughter)
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(聽眾笑聲)
06:08
So, this -- what I saw, on every single mantis shrimp limb,
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所以,這個就是,我注意到螳螂蝦的每個枝節上
06:13
whether it's a spearer or a smasher,
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不論是穿刺型或粉碎型,
06:15
is a beautiful saddle-shaped structure
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牠們都有這個非常美麗的馬鞍型構造
06:17
right on the top surface of the limb. And you can see it right here.
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在這些枝節最頂端表面上。而你在這裡可以看到。
06:21
It just looks like a saddle you'd put on a horse.
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他看起來就像是那些你會放在馬匹上的馬鞍。
06:23
It's a very beautiful structure.
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是非常美麗的結構。
06:25
And it's surrounded by membranous areas. And those membranous areas
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這些馬鞍構造,被膜狀區域包圍。這些膜狀區域
06:30
suggested to me that maybe this is some kind of dynamically flexible structure.
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讓我推測這可能是一種動力彈性的構造。
06:34
And this really sort of had me scratching my head for a while.
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這的確讓我搔頭苦思了好一段時間。
06:37
And then we did a series of calculations, and what we were able to show
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然後我們做了一些計算,我們得到的結論是
06:41
is that these mantis shrimp have to have a spring.
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這些螳螂蝦一定都有彈簧。
06:45
There needs to be some kind of spring-loaded mechanism
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牠們一定要有某種類似彈簧構造的機制
06:48
in order to generate the amount of force that we observe,
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以累積我們觀察到那樣強大的能量、
06:50
and the speed that we observe, and the output of the system.
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那樣的速度、還有那樣的系統。
06:53
So we thought, OK, this must be a spring --
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所以我們想,好吧,那這個一定就是那個彈簧:
06:56
the saddle could very well be a spring.
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這個馬鞍狀的東西很有可能就是彈簧。
06:58
And we went back to those high-speed videos again,
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所以我們又把那些高速的影帶找出來,
07:00
and we could actually visualize the saddle compressing and extending.
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我們可以確實看到那些鞍部構造收縮延伸。
07:06
And I'll just do that one more time.
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我把這個片段再放一次。
07:09
And then if you take a look at the video --
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你們仔細看這個片段:
07:11
it's a little bit hard to see -- it's outlined in yellow.
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那有一點難以觀察,我用黃色標起來的區域。
07:13
The saddle is outlined in yellow. You can actually see it
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我用黃色把鞍部標記起來。你們確實可以看到
07:15
extending over the course of the strike, and actually hyperextending.
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它在出擊的過程中延展,實際上是過度伸展。
07:19
So, we've had very solid evidence showing
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所以我們有非常強而有力的證據可以證明
07:21
that that saddle-shaped structure actually compresses and extends,
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這些馬鞍形狀的構造確實會收縮延伸,
07:25
and does, in fact, function as a spring.
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而實際上,正是像彈簧一般作用。
07:27
The saddle-shaped structure is also known as a "hyperbolic paraboloid surface,"
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這個鞍型結構也被稱為一個雙曲拋物面,
07:32
or an "anticlastic surface."
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或是一個鞍型面。
07:34
And this is very well known to engineers and architects,
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這在工程或建築界裡是非常著名的,
07:36
because it's a very strong surface in compression.
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因為這在壓縮的過程中是非常強壯的介面。
07:39
It has curves in two directions,
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它有兩個方向不同的曲線,
07:41
one curve upward and opposite transverse curve down the other,
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一面彎曲向上,相反的那面彎曲向下,
07:44
so any kind of perturbation spreads the forces
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所以不管用那一搖晃
07:47
over the surface of this type of shape.
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它都能讓能量區暈分散在兩面。
07:50
So it's very well known to engineers, not as well known to biologists.
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所以在工程師界這是非常著名的,對生物學家來說卻不是。
07:54
It's also known to quite a few people who make jewelry,
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這個構造對那些製作珠寶的人來說,也是相當熟悉,
07:58
because it requires very little material
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因為製造這樣的表面,
08:01
to build this type of surface, and it's very strong.
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只需要用到非常少的原料,但他卻非常強壯。
08:04
So if you're going to build a thin gold structure,
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所以你如果要製作一個薄的黃金結構,
08:06
it's very nice to have it in a shape that's strong.
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能用有一個夠強壯的形狀是好的。
08:08
Now, it's also known to architects. One of the most famous architects
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這對建築師們來說也是非常熟悉的。非常著名的建築師之一
08:13
is Eduardo Catalano, who popularized this structure.
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Eduardo Catalano就是以使用這個架構聞名。
08:16
And what's shown here is a saddle-shaped roof that he built
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這裡顯示的,是他所建築的一個鞍型天花板
08:19
that's 87 and a half feet spanwise.
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單曲面長約26.62公尺
08:23
It's two and a half inches thick, and supported at two points.
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厚度只有6.35公分,就靠那兩點支撐。
08:26
And one of the reasons why he designed roofs this way is because it's --
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他選擇用這樣的結構來設計屋頂的其中一個原因,
08:31
he found it fascinating that you could build such a strong structure
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便是他驚訝的發現,你竟然可以用這樣少的材料
08:35
that's made of so few materials and can be supported by so few points.
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建造這樣強壯的結構,而且只需要靠幾個點來支撐。
08:39
And all of these are the same principles that apply
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而這些,全部都是利用同樣的原理
08:43
to the saddle-shaped spring in stomatopods.
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像螳螂蝦的鞍型彈簧那樣。
08:45
In biological systems it's important not to have a whole lot
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在生物系統裡,如果能不用多餘的原料
08:48
of extra material requirements for building it.
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去產生一個結構是非常重要的。
08:51
So, very interesting parallels between the biological
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所以,這是一個非常有趣的平行對照,
08:54
and the engineering worlds. And interestingly, this turns out --
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在生物界與工程界之間。而有趣的是,
08:58
the stomatopod saddle turns out to be the first
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結果螳螂蝦的鞍部,竟成為
09:00
described biological hyperbolic paraboloid spring.
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第一個被發現的生物雙曲面彈簧結構
09:03
That's a bit long, but it is sort of interesting.
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這故事有點長,但有些有趣。
09:06
So the next and final question was, well, how much force
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所以下一個和最後一個問題是,那麼螳螂蝦
09:09
does a mantis shrimp produce if they're able to break open snails?
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需要多少的力量才能打開一個螺?
09:13
And so I wired up what's called a load cell.
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我因此設立的一個承種傳感器。
09:15
A load cell measures forces, and this is actually
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承重傳感器,可以用來量測各種承重壓力,而這個實際上
09:17
a piezoelectronic load cell that has a little crystal in it.
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壓電的承重傳感器,裡頭有一個小小的水晶。
09:20
And when this crystal is squeezed, the electrical properties change
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當這顆水晶受到擠壓,按照不同推擠壓力的大小,
09:24
and it -- which -- in proportion to the forces that go in.
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電器性能便會改變。
09:26
So these animals are wonderfully aggressive,
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所以這些動物都具有非常美好的攻擊性,
09:29
and are really hungry all the time. And so all I had to do
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而牠們總是處於飢餓狀態。所以我要做的
09:32
was actually put a little shrimp paste on the front of the load cell,
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就只是放一點飼料在這個傳感器的前方,
09:35
and they'd smash away at it.
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牠們便會對它發動攻擊。
09:37
And so this is just a regular video of the animal
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這只是一個非常平常的短片
09:41
just smashing the heck out of this load cell.
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只是這蝦子如何瘋狂試圖擊毀傳感器。
09:44
And we were able to get some force measurements out.
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我們得以量測一些結果。
09:47
And again, we were in for a surprise.
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然後再一次,又是個驚喜。
09:49
I purchased a 100-pound load cell, thinking,
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我買了一個最高可測到一百磅(約45公斤)的傳感器,
09:51
no animal could produce more than 100 pounds at this size of an animal.
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我心裡想,沒有任何這個尺寸的動物,可以製造出高於百磅的能量。
09:55
And what do you know? They immediately overloaded the load cell.
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然而你怎麼會想到,牠們立刻就擊出超過傳感器負重的力量。
09:57
So these are actually some old data
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這些實際上是一些舊的研究數據
09:59
where I had to find the smallest animals in the lab,
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我找了一些實驗室裡最小的動物,
10:01
and we were able to measure forces of well over 100 pounds
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卻量出了超越一百磅的能量,
10:04
generated by an animal about this big.
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從這麼小的動物身上。
10:07
And actually, just last week I got a 300-pound load cell
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而實際上,就在上個禮拜,我買了最多可以測到300磅(約135公斤)的傳感器
10:09
up and running, and I've clocked these animals generating
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而我用此紀錄到這些蝦子
10:12
well over 200 pounds of force.
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製造超過200磅的能量。
10:14
And again, I think this will be a world record.
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又一次,我想這應該破了世界紀錄。
10:17
I have to do a little bit more background reading,
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我得多讀一些背景研究的資料,
10:19
but I think this will be the largest amount of force produced
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但是我想這應該會是這個尺寸的動物
10:22
by an animal of a given -- per body mass. So, really incredible forces.
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所被記錄到製造出的最大能量。這是相當驚人的。
10:27
And again, that brings us back to the importance of that spring
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所以這又把我們帶回到彈簧的重要性
10:30
in storing up and releasing so much energy in this system.
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它在這個系統中儲存且釋放了這麼多能量。
10:34
But that was not the end of the story.
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但這並不是故事的結局。
10:36
Now, things -- I'm making this sound very easy, this is actually a lot of work.
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現在的進度是;喔,我把這講得好像很簡單,其實費了很大一段功夫。
10:39
And I got all these force measurements,
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我把這些量測到的出擊力量,
10:41
and then I went and looked at the force output of the system.
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和整個系統產出的能量相比。
10:45
And this is just very simple -- time is on the X-axis
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這部分其實非常簡單,X軸是時間
10:48
and the force is on the Y-axis. And you can see two peaks.
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能量在Y軸。你會看到有兩個高峰。
10:51
And that was what really got me puzzled.
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這就是讓我非常困惑的部分。
10:55
The first peak, obviously, is the limb hitting the load cell.
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第一個尖峰,顯然,是枝節點擊到傳感器的時候。
10:58
But there's a really large second peak half a millisecond later,
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但是在不到百萬分之一秒間,有另外一個非常顯著的高峰,
11:04
and I didn't know what that was.
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而我不知道那是什麼。
11:06
So now, you'd expect a second peak for other reasons,
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所以現在,你會預期第二個高峰,基於其他因素,
11:09
but not half a millisecond later.
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但是不是在不到百萬分之一秒之後。
11:11
Again, going back to those high-speed videos,
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所以我們再次回去看高速影帶,
11:13
there's a pretty good hint of what might be going on.
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那裡有個非常好的暗示,告訴我們可能發生了什麼事。
11:17
Here's that same orientation that we saw earlier.
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這和我們稍早看到的是同一個方向
11:19
There's that raptorial appendage -- there's the heel,
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這是攻擊用的附枝,這是後跟,
11:22
and it's going to swing around and hit the load cell.
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牠正準備要揮拳擊打傳感器。
11:25
And what I'd like you to do in this shot is keep your eye on this,
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而在這個鏡頭,我希望你們可以把注意力放在這裡,
11:28
on the surface of the load cell, as the limb comes flying through.
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傳感器的表面,當蝦子把枝節揮舞過來的時候
11:33
And I hope what you are able to see is actually a flash of light.
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我希望你們可以看到的,實際上是個閃光。
11:38
Audience: Wow.
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聽眾:哇!!
11:40
Sheila Patek: And so if we just take that one frame, what you can actually see there
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我們接著如果固定在這個畫面,你實際上可以看到
11:44
at the end of that yellow arrow is a vapor bubble.
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在那個黃色的箭頭尾端有個水氣的泡泡。
11:47
And what that is, is cavitation.
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而那其實,是個氣穴。
11:49
And cavitation is an extremely potent fluid dynamic phenomenon
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氣穴是一個極端有力的流體動力現象
11:53
which occurs when you have areas of water
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這個現象發生於一個水域中的水分子
11:56
moving at extremely different speeds.
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以各種差異極大的速度移動。
11:58
And when this happens, it can cause areas of very low pressure,
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當這個現象發生的時候,會讓這個區域產生非常低的壓力,
12:02
which results in the water literally vaporizing.
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這個低壓,會讓水蒸發。
12:05
And when that vapor bubble collapses, it emits sound, light and heat,
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當這些水氣的泡泡破掉的時候,它會發出聲音、光、和熱,
12:09
and it's a very destructive process.
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這是一個非常具有破壞性的過程。
12:11
And so here it is in the stomatopod. And again, this is a situation
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所以,這是那隻螳螂蝦。然後再一次,我們又回到同樣的情況
12:16
where engineers are very familiar with this phenomenon,
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工程師們對於這個現象非常熟悉,
12:19
because it destroys boat propellers.
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因為氣穴現象會破壞船隻的螺旋推進器。
12:21
People have been struggling for years to try and design
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人們花了很多年努力嘗試和設計
12:24
a very fast rotating boat propeller that doesn't cavitate
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一個可以快速轉動卻不會造成氣穴現象的螺旋槳
12:28
and literally wear away the metal and put holes in it,
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一點都不誇張,氣穴會磨損金屬,在上面打出洞來,
12:30
just like these pictures show.
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就像這些照片裡面顯示的。
12:32
So this is a potent force in fluid systems, and just to sort of take it one step further,
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這是一個非常強而有力的流體系統,
12:41
I'm going to show you the mantis shrimp approaching the snail.
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我將向你們展式螳螂蝦接近螺的片段。
12:44
This is taken at 20,000 frames per second, and I have to give
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這是以每秒鐘兩萬片幅的速度拍攝,我得特別謝謝
12:48
full credit to the BBC cameraman, Tim Green, for setting this shot up,
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英國皇家廣播公司的攝影師,Tim Green,架設拍攝這段影片,
12:52
because I could never have done this in a million years --
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因為要是自己來,我一輩子都不可能完成這個影片的拍攝。
12:55
one of the benefits of working with professional cameramen.
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這是其中一個和專業攝影師工作的好處。
12:58
You can see it coming in, and an incredible flash of light,
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你可以看到有什麼正要發生,是一股令人驚嘆的閃光,
13:02
and all this cavitation spreading over the surface of the snail.
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這些氣穴遍布螺殼的表面。
13:06
So really, just an amazing image,
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所以,說真的,這純粹就是一個不可思議的畫面,
13:09
slowed down extremely, to extremely slow speeds.
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我們把速度放慢,放得極慢。
13:13
And again, we can see it in slightly different form there,
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然後,我們可以從這裡看到一些不一樣的東西,
13:16
with the bubble forming and collapsing between those two surfaces.
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這些水氣怎樣在兩個表殼上生成和瓦解。
13:20
In fact, you might have even seen some cavitation going up the edge of the limb.
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事實上,你可能已經看過這些氣穴從枝節的邊緣上升。
13:25
So to solve this quandary of the two force peaks:
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所以,解答這個兩個出力高峰的問題:
13:28
what I think was going on is: that first impact is actually
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我認為,第一個高峰,實際上
13:30
the limb hitting the load cell, and the second impact is actually
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是枝節擊中傳感器上的時候,而第二個高峰,則是
13:33
the collapse of the cavitation bubble.
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那些氣穴的水泡瓦解的時候。
13:35
And these animals may very well be making use of
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而這些動物們,很有可能
13:38
not only the force and the energy stored with that specialized spring,
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不單只是利用這個特製彈簧夾所儲存的能量,
13:42
but the extremes of the fluid dynamics. And they might actually be
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而更進一步的利用了極端的流體動力。而牠們實際上
13:46
making use of fluid dynamics as a second force for breaking the snail.
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有可能正是利用這些流體動力為牠們的第二進能量去擊毀螺殼。
13:50
So, really fascinating double whammy, so to speak, from these animals.
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換句話說,是從這些動物們發出,非常令人驚嘆的雙重攻擊,
13:56
So, one question I often get after this talk --
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有一個演講後,我經常被問到的問題,
13:58
so I figured I'd answer it now -- is, well, what happens to the animal?
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我想不如現在一起回答,這個問題是,那螳螂蝦自己呢?
14:01
Because obviously, if it's breaking snails,
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因為很明顯的,如果氣穴現象可以打破螺殼,
14:04
the poor limb must be disintegrating. And indeed it does.
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那些可憐的枝節想必也被支解了。而沒錯,正是如此。
14:07
That's the smashing part of the heel on both these images,
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這兩張照片中,都是後跟用來粉碎的部分,
14:10
and it gets worn away. In fact, I've seen them wear away
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它們會被磨損。實際上,我就看過它們被磨損
14:12
their heel all the way to the flesh.
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一路甚至可以看到肉。
14:14
But one of the convenient things about being an arthropod
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但是身為螳螂蝦,有一件非常方便的事情就是
14:17
is that you have to molt. And every three months or so
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牠們必須要蛻皮換殼。大概每三個月一次
14:20
these animals molt, and they build a new limb and it's no problem.
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這些蝦蛄會開始蛻殼,長出新的枝節,所以沒有問題。
14:25
Very, very convenient solution to that particular problem.
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對解決這個特定問題來說,是一個非常,非常方便的方案。
14:29
So, I'd like to end on sort of a wacky note.
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所以,我想要為我的演講,下一個有點怪的結論。
14:34
(Laughter)
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(聽眾笑聲)
14:37
Maybe this is all wacky to folks like you, I don't know.
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或者整個演講對你們來說都很古怪,我不知道。
14:41
(Laughter)
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(聽眾笑聲)
14:42
So, the saddles -- that saddle-shaped spring --
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所以,鞍部,這些鞍狀的彈簧
14:45
has actually been well known to biologists for a long time,
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實際上在生物學界已廣為人知,
14:49
not as a spring but as a visual signal.
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不是以彈簧這個功用,而是視覺訊號。
14:53
And there's actually a spectacular colored dot
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在很多不同種螳螂蝦的鞍部中央
14:55
in the center of the saddles of many species of stomatopods.
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都有一個顏色引人入勝的彩色斑點。
15:01
And this is quite interesting, to find evolutionary origins
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要找到這個班點,實際上是個彈簧,的演化源頭,
15:04
of visual signals on what's really, in all species, their spring.
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是還滿有趣的一件事。
15:10
And I think one explanation for this could be
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而我想其中一個解釋的可能
15:12
going back to the molting phenomenon.
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我們得回到瞎子蛻皮的現象。
15:14
So these animals go into a molting period where they're
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當這些蝦子經歷蛻皮的階段
15:17
unable to strike -- their bodies become very soft.
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牠們沒有辦法發動攻擊,牠們的身體變得非常柔軟。
15:20
And they're literally unable to strike or they will self-destruct.
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牠們真的沒辦法攻擊,不然牠們會傷害到自己。
15:23
This is for real. And what they do is, up until that time period
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這是很嚴重的事。所以牠們解決的辦法,便是一直到
15:30
when they can't strike, they become really obnoxious and awful,
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牠們沒辦法攻擊的期間,牠們會變得非常討厭和糟糕,
15:33
and they strike everything in sight; it doesn't matter who or what.
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牠們會攻擊視野所見所有東西,不管是誰或是什麼東西。
15:37
And the second they get into that time point when they can't strike any more,
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而當牠們進入沒辦法攻擊的瞬間,
15:41
they just signal. They wave their legs around.
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牠們就發出訊號。牠們揮舞枝節。
15:44
And it's one of the classic examples in animal behavior of bluffing.
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這是動物們吹牛的一個非常經典的行為。
15:48
It's a well-established fact of these animals
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這在這個物種中已經是個建立的事實,
15:50
that they actually bluff. They can't actually strike, but they pretend to.
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牠們真的會吹牛。牠們不能攻擊,可是牠們會假裝可以。
15:54
And so I'm very curious about whether those colored dots
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所以我非常好奇那些鞍座中
15:56
in the center of the saddles are conveying some kind of information
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的彩色斑點,是不是在傳遞某種訊息
16:00
about their ability to strike, or their strike force,
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關於牠們發動突襲的能力,或強度,
16:03
and something about the time period in the molting cycle.
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還有部份關於牠們在哪個蛻皮階段的資訊。
16:06
So sort of an interesting strange fact to find a visual structure
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所以,在牠們彈簧鞍部的中間
16:11
right in the middle of their spring.
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發現這樣一個視覺結構,還滿奇怪但有趣的。
16:14
So to conclude, I mostly want to acknowledge my two collaborators,
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最後,我想要向我的兩個合作夥伴致謝,
16:19
Wyatt Korff and Roy Caldwell, who worked closely with me on this.
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Wyatt Korff和Roy Caldwell兩位和我共同完成這個研究。
16:22
And also the Miller Institute for Basic Research in Science,
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另外我也要感謝Miller Institute對基礎科學研究的資助,
16:25
which gave me three years of funding to just do science all the time,
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它們贊助了我整整三年的研究基金,讓我專心做研究,
16:29
and for that I'm very grateful. Thank you very much.
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為此,我心存感激。謝謝大家。
16:32
(Applause)
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(聽眾鼓掌)
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