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  • It’s hard to imagine just how tiny atoms are.

    很難去想像究竟原子有多小

  • One sheet of paper is roughly half a million atoms thick.

    比一張紙大約薄了五十萬分之一

  • Volume-wise, one atom is as small compared

    體積觀點來看,把一個原子比喻成一顆蘋果

  • to an apple as that apple is to the entire earth.

    如同一顆蘋果對比於整個地球

  • So you might be surprised to learn that

    所以你應該會訝異得知

  • chemists can actually see atoms.

    化學家能確實看到原子

  • Not with their eyes.

    不是透過他們的雙眼

  • With incredibly precise tools.

    而是令人難以置信地精密工具

  • [Legends of Chemistry intro]

    [化學傳奇介紹]

  • The idea of atoms stretches back to ancient Greece,

    原子這個想法可以延伸到古希臘

  • when the philosopher Democritus declared that

    當哲學家德謨克利特宣稱

  • all matter is made of tiny particles.

    所有事物都由微小粒子所組成的

  • The philosopher Plato even decidedwronglythat

    哲學家柏拉圖甚至無疑(現在看來是錯誤)地說

  • different substances had differently

    不同物質擁有不同

  • shaped atoms, like pyramids or cubes.

    形狀的原子,像是三角錐體或立方體

  • The first modern evidence for atoms appeared

    第一個原子的近代證據發現

  • in the early 1800s, when British chemist

    於1800年早期,當時還是大不列顛的化學家

  • John Dalton discovered that chemicals always

    約翰.道耳頓發現化合物總是

  • contain whole-number ratios of elements.

    含有整數倍比例的元素

  • That’s why it’s H2O and not H2.4O or H√17O.

    這就是為什麼它是H2O而不是H2.4O或H√17O

  • The reason for these whole numbers, Dalton

    由於這些都是整數,道耳頓

  • suggested, was because you can’t have a half

    認為,因為你無法找到半顆原子

  • an atom or point-two atoms, only whole atoms.

    或0.2顆原子,只有完整的原子

  • It’s hard to imagine chemistry today without Dalton’s insight.

    難以想像現今化學沒有道耳頓的觀點

  • But it was actually controversial in its day.

    但它實際上爭論了好些日子

  • Why?

    這是為何?

  • Because chemists couldn’t see atoms.

    因為化學家無法用雙眼看到原子

  • Many considered them like negative numbers

    有很多值得考慮的,像是負整數

  • or ideal gases: useful for calculating things,

    或理想氣體:計算東西能幫上忙

  • but not existing in the real world.

    但是不存在於真實世界

  • Even Dmitri Mendeleev, father of the periodic table,

    甚至元素週期表之父:德米特里.門得列夫

  • refused to believe in atoms for many years.

    拒絕去相信原子論很多年

  • Why didn’t chemists just look for atoms under microscopes?

    為何化學家不把原子放到顯微鏡下觀察就好?

  • To see something under a microscope, the wavelength

    在顯微鏡下想看見東西,

  • of light youre shining through the microscope

    透過顯微鏡觀看物體發出的光波長

  • can't be larger than whatever youre looking at.

    無論你看的是什麼要落於可見光波長

  • Unfortunately, visible light is thousands of times bigger than atoms.

    不幸地,可見光的波長比原子大了千倍以上

  • So chemists had to wait for light with

    所以化學家必須直到光有

  • shorter wavelengths, like x-rays.

    更短的波長,像是X射線

  • X-rays were discovered in the 1890s by

    X射線在1890年被發現,由

  • German scientist Wilhelmntgen, who

    德國科學家威廉.倫琴

  • realized that photographs taken with x-rays

    他明白了使用X射線攝影的方法

  • allowed him to see through objects.

    能讓他看穿透物體

  • Roentgen thought he’d gone insane when

    當倫琴看見這個,為之瘋狂

  • he saw this, but today were all familiar with

    但是在今天的我們都熟悉

  • x-rays from trips to the dentist and doctor.

    X射線,透過看牙醫和醫生

  • Chemists don’t use x-rays to see through things.

    化學家們不是使用X射線去看穿東西

  • Instead, they bounce x-rays off things like crystals,

    反而,他們對東西彈射X射線像水晶

  • which are solids with layers of atoms. When x-rays

    晶體是一層層原子的固體。當X射線

  • hit an atom in a crystal, they bounce back.

    打中一個水晶中的原子,他們彈射回去

  • Others slip through and bounce off the second layer down.

    其它的滑行穿過,在第二層反彈

  • Or the third layer, or deeper.

    或第三層,或更深入的層

  • After being reflected, these x-rays strike a detector

    反射過後,這些X射線擊中偵測器的

  • screen, like the ball bouncing back in Pong.

    螢幕,像是在乓(桌球遊戲)中彈回來的球

  • And based on where the x-rays came from

    基於X射線照射到的地方

  • and how they interacted with each other,

    和他們如何互相影響彼此

  • scientists can work backward and figure out

    科學家能反推和找出

  • the arrangement of atoms in the crystal.

    水晶中的原子排列

  • This reflection and interaction of light rays is called diffraction.

    這個反射和光射線的相互作用稱為繞射

  • X-ray diffraction, sometimes called x-ray

    X射線繞射,有時候稱為X射線

  • crystallography, has led to dozens of

    晶體學,從1920年開始導致一大堆的

  • Nobel Prizes for chemists since the 1920s.

    諾貝爾化學獎得主產生

  • It also led to one of the biggest discoveries in science

    它也導致科學史上最重大的發現

  • history, the structure of DNA. James Watson and

    DNA的結構,詹姆斯.華生和

  • Francis Crick get credit nowadays, but they based

    佛朗西斯.克里克得到當今榮譽,但是他們是基於

  • their work on the work of Rosalind Franklin,

    他們是在研究羅莎琳.富蘭克林的研究成果

  • a crystallographer in England.

    她是一位在英格蘭的晶體學家

  • She began taking x-ray pictures of DNA in 1952,

    在1952年,她開始拍攝DNA的X射線照片

  • and Watson’s glimpse of one picturephotograph 51.

    華生瞥見其中一張照片-照片51

  • was the vital clue in determining that

    它是重大線索決定了

  • DNA was a double helix.

    DNA是一個雙螺旋結構

  • This incident remains controversial today

    今天這個意外至今仍然爭論

  • Because Franklin never gave Watson

    因為富蘭克林從未給予沃森

  • permission to view photograph 51.

    許可去查看照片51(實際是他同事給他看的)

  • If x-rays let chemists peer at the structure of atoms,

    如果X射線能讓化學家們看到原子的結構

  • scanning tunneling microscopes

    掃描式通道顯微鏡

  • finally revealed atoms themselves.

    終於讓原子顯現出他們自己

  • Rather than bounce light off something,

    而不是光線彈跳在某個東西

  • an STM runs a sharp needle over its surface.

    一台掃描式通道顯微鏡驅動一根尖的針狀物在它的表面

  • It’s like chemical Braille, except

    它就像化學版布拉耶點字法(盲文)

  • the tip never quite touches.

    尖端從不完全接觸

  • As the tip moves along the surface, scientists

    當尖端沿著表面移動,科學家們

  • can reconstruct the atomic landscapemaking

    能重建原子的圖像

  • individual atoms visible at last in the early 1980s.

    讓個別的原子可被看見,至少在1980年早期

  • Lo and behold, the atoms weren’t Plato’s cubes

    你瞧,原子形狀不是柏拉圖的立方體

  • and pyramids, but spheres of different sizes.

    和三角錐體,而是不同大小的球體

  • By 1989 a few scientists had even adapted

    在1989年,一些科學家開始採用

  • STM technology to manipulate single

    掃描式通道顯微鏡技術運用在單一

  • xenon atoms and spell out words.

    氙原子和拼寫出來單字

  • Well let you guess what company they worked for.

    我們讓你猜猜他們為哪個公司工作

  • Also in 1989, the chemist Ahmed Zewail moved

    也再1989年,化學家亞米德·齊威爾

  • beyond looking at stationary atoms and

    進一步超過觀看靜態的原子

  • developed tools to see atoms in action.

    開發工具去觀察原子的活動

  • Zewail wanted to study how atoms break bonds

    齊威爾想要研究原子如何突破束縛

  • and swap partners during reactions.

    在化學反應時交換原子

  • So he developed the world’s fastest camera,

    所以他開發出世界上最快的照相機

  • which shoots pulses of laser light a few femtoseconds

    發射雷射脈波在幾個飛秒長的時間

  • long—a few billionths of a microsecond.

    是幾個毫秒的十億分之一

  • If you stretched one femtosecond to a full second,

    如果你展開一飛秒到一秒上

  • it would be like stretching a single

    它就像是展開一秒

  • second out to 32 million years.

    對三千二百萬年

  • While Zewail’s laser flashed like a strobe, his camera snapped pictures.

    當齊威爾的雷射閃光像閃控,透過相機用快照拍攝照片

  • Zewail then ran the pictures together

    齊威爾將相片收集在一起

  • like a slow-motion replay.

    像慢動作重播

  • Since then femtochemistry had provided insight into

    從那時以來飛秒化學提供洞察力在

  • everything from ozone depletion to the workings

    每件事情上,從臭氧用盡到

  • of the human retina. Zewail won a Nobel Prize

    人類視網膜的活動。在1999年,齊威爾獲得諾貝爾獎

  • in chemistry for his work in 1999.

    紀念他在化學的成就

  • The ancient Greeks dreamed up fanciful shapes for atoms.

    古希臘對於原子的形狀充滿幻想

  • But it took 2,400 years before scientists could see

    但它花了二千四百年的時間,直到科學家能夠真實看見

  • them for real and study their behavior.

    他們和研究它們的行為

  • Seeing truly is believing for human beings, and it was

    對人類來說眼見為憑,它是

  • chemists and other scientists who fulfilled this need

    化學家和其它科學家實現這個需求

  • and finally revealed what our universe is made of.

    最後展示我們的宇宙是由什麼組成

  • Thanks for watching chemheads.

    感謝你收看chemheads

  • Be sure to check out other videos in the

    你也可以收看其它的影片在

  • Legends of Chemistry series, Like the Woman

    化學傳奇系列,像

  • Who Saved the U.S. Space Program, and

    拯救美國的太空計劃的女人和

  • the crafty scientists who tricked the Nazis.

    欺詐納粹的狡猾科學家

  • Don’t forget to hit the subscribe button

    別忘了去點擊訂閱按鈕

  • for weekly chemistry awesomeness.

    收看每週的化學大驚奇

It’s hard to imagine just how tiny atoms are.

很難去想像究竟原子有多小

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你怎麼能看到一個原子? (How Can You See an Atom?)

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    Nina 發佈於 2021 年 01 月 14 日
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