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  • This is the first live cat recorded on film, and it's being dropped to solve a physics problem: Why do cats always land on their feet?

    這是第一個活著的貓的影像紀錄,他被高高丟下的畫面解決了一個物理難題:為什麼貓咪總是可以四腳落地?

  • It's a question that was driving 19th century scientists nuts.

    這個問題真的快把 19 世紀的科學家逼瘋了。

  • Until one of them used an unexpected tool to solve the mystery: a camera.

    直到他們其中一人用了讓人意想不到工具才解決這個謎:相機。

  • Étienne-Jules Marey was an obsessive scientist and inventor who analyzed how things moved.

    艾蒂安.朱爾.馬雷對科學及發明很著迷,他喜歡分析物體如何運動。

  • And he started experimenting with photography at a time when the medium was mostly used to document static subjects.

    當大多數的人都還在以靜物作為研究媒介時,他已經開始用攝影來設計實驗了。

  • But his goal was to capture motion.

    他的目標是捕獲那些物體的運動。

  • And he did that by building on a basic principle of photography: exposing a photosensitive material to light and then covering it in darkness.

    他以攝影的基本原則為基礎,先將感光材料曝露在燈光下,再將之罩起。

  • So his way of creating this darkness and light was to have a disc with slots in it.

    為了要製造明暗,他的做法是在圓盤上面挖出狹縫。

  • By controlling the light as the subject moved across the frame, Marey was able to record movement onto a single glass plate.

    當物體在鏡頭前移動時,馬雷藉由控制光線將運動過程記錄在單片玻璃上。

  • Essentially, all he does is block that light intermittently.

    基本上,他做的就是間歇性的阻擋光線。

  • A slot from the disc opens, and then there's darkness as the man moves, opens, darkness.

    光線進入狹縫時會製造出影像,接著人移動時光線便被阻擋,一明一暗不斷交錯。

  • This technique is called chronophotography, and the results show something human eyes will never see on their own: individual stages of motion.

    這種技術叫定時攝影,它可以讓我們看見人眼看不到的東西:物體的個別運動階段。

  • A couple of years later, Kodak introduced celluloid film and Marey updated his slot camera in a crucial way.

    幾年後,柯達採用賽璐珞底片,馬雷隨後也將他的插槽式相機升級,這個轉變十分關鍵。

  • He swapped the single glass plate with a roll of film that moved in between exposures.

    他改用一捲底片代替單片玻璃來曝光。

  • So, light: an image is made.

    有光的時候,就會顯現影像。

  • Darkness, the film moves on.

    暗的時候底片就會轉動。

  • Light, an imageso it's a movie camera, is what it is.

    有光又出現影像,這就是電影照相機。

  • Marey made a lot of films for research purposes.

    為了研究,馬雷拍攝了許多影片。

  • And even tried dropping other animals to see if they'd land on their feet, specifically this rabbit and this chicken.

    甚至嘗試讓其它動物落下,看他們能不能以腳著地,像是這隻兔子和這隻雞。

  • Which brings us back to the cat.

    這也讓我們的主題回到貓咪。

  • It seems to be able to right itself by flipping in the air without pushing off anything first, which would contradict the law of conservation of angular momentum.

    貓咪似乎可以不用對任何東西施力就在空中翻轉身體,但這樣會跟角動量守恆定律相衝突。

  • Sounds scary, but stick with me here.

    聽起來有點可怕,但請繼續聽我解釋。

  • One of Newton's laws of motion says that something in motion can't just stop itself unless an opposing force acts upon it.

    其中一個牛頓運動定律說到:一個移動中的物體無法自己停下來,除非有反方向的力作用於他身上。

  • Basically, you can't just change direction midair, Wile E. Coyote style.

    基本上你不能像威利狼與嗶嗶鳥一樣在半空中改變方向。

  • But to the naked eye, it looks like a cat can.

    但就肉眼看來,貓咪好像就是可以做到。

  • Most people assumed the cat was "cheating" by kicking off the hands of the person dropping it.

    多數人認為貓咪是用腳蹬人的手來做弊的。

  • But Marey's film showed what's actually happening.

    馬雷的影像說明了這段過程中到底發生什麼事。

  • The first few frames prove right away that the cat doesn't start its rotation from a kick.

    前面幾幀照片就證實了,貓咪一開始並沒有用踢的方式來旋轉方向。

  • But what it does do is arch its back.

    但牠弓起了牠的背部。

  • And by arching its back, it's divided its body into a front part and a back part, and the two parts can work independently.

    弓起背部後,牠將身體分為前半部與後半部,這兩部分可以分開來活動。

  • You know how a figure skater pulls their arms in to rotate faster?

    你知道花式滑冰員是如何藉由收攏雙臂來越轉越快的嗎?

  • That's whats happening here, too.

    貓咪旋轉的原理也是這樣。

  • Early in the rotation, the cat pulls its front legs in and leaves the back splayed out.

    剛開始旋轉時,貓咪會將前腳收起,背部維持伸展的樣子。

  • So the front half can rotate quickly while the back half stays relatively still.

    所以牠的前半部就可以快速轉動,而後半部可以保持靜止。

  • Then halfway through, it does the opposite.

    要轉動身體後半部時則相反。

  • Front legs stretched out, back ones tucked in to flip the other half of its body around.

    牠會將前腳身直、後腳縮起來,好讓後半部的身體轉向。

  • And you notice by the time the cat is landing, all four legs are stretched out as far as they can be, which means slow rotation.

    你會注意到當貓咪落地時,牠們的四隻腳會盡可能地伸直,讓身體能夠轉得較慢。

  • So the cat has rotated itself, but not overall; the two halves are working in opposite ways.

    所以貓咪的確可以靠自己在空中旋轉,但是是將身體分成兩半部,以相反方向來運作。

  • It uses the inertia of its own bodyweight to spin each side.

    牠利用自身體重的慣性來旋轉。

  • And because the two spins operate separately in opposing directions, they cancel each other out.

    因為前、後半部的旋轉方向恰恰相反,因此兩個力就可以互相抵銷。

  • So Newton's law isn't broken.

    所以牛頓的定律並沒有被打破。

  • Marey published his findings in Nature in 1894, breaking down the falling cat problem for the first time.

    馬雷將牠的發現刊登在 1894 年的《自然》期刊上,第一次解開了「為何貓咪可以穩穩落地」的問題。

  • His work remains an early example of using photography for scientific discovery.

    他的這項成果便是早期運用攝影來挖掘科學真相的實例。

  • What does photography do for science?

    攝影技術對科學做出了什麼貢獻呢?

  • It records something and it makes it permanent so you can analyze it later, or so you can share it.

    它可以記錄下某件事,讓那一刻永久保存,所以我們就可以加以分析或分享給別人。

  • But what Marey did was show something that the eye could not possibly seeever.

    但馬雷所做出的貢獻是讓我們看見人眼永遠無法看見的事物。

  • You might have seen another famous early example of motion photography.

    你可能看過早期另一個很有名的例子,也是拍攝物體的運動。

  • In 1878, Eadweard Muybridge used 12 cameras connected to tripwires to prove that a horse lifts all four feet off the ground at some point in a gallop.

    1878 年,埃德沃德.邁布里奇用導線將 12 台相機連接在一起,最後證明馬隻有時在急速奔馳時會四蹄騰空。

This is the first live cat recorded on film, and it's being dropped to solve a physics problem: Why do cats always land on their feet?

這是第一個活著的貓的影像紀錄,他被高高丟下的畫面解決了一個物理難題:為什麼貓咪總是可以四腳落地?

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你的腳底有磁鐵吧!為什麼貓貓總是能安全落地? (Why a cat always lands on its feet)

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    Vivian Chen 發佈於 2019 年 06 月 21 日
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