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  • One of the most amazing facts in physics is this:

    在物理學最令人驚訝的事實就是:

  • everything in the universe, from light to electrons to atoms,

    宇宙中的一切,從光到電子、原子,

  • behaves like both a particle and a wave at the same time.

    其行為同時具備粒子及波動的特性,

  • All of the other weird stuff you might have heard about quantum physics,

    所有其他怪異的東西, 你可能在量子物理中聽過,

  • Schrodinger's Cat, God playing dice, spooky action at a distance,

    「薛丁格的貓」、「上帝玩骰子」 及「鬼魅般的交互作用」

  • all of it follows directly from the fact

    這一切皆因

  • that everything has both particle and wave nature.

    萬物同時具備粒子及波動的特性而來。

  • This might sound crazy.

    這聽起來似乎很瘋狂,

  • If you look around, you'll see waves in water and particles of rock,

    如果環顧四周,你看到 海浪與岩石上的顆粒,

  • and they're nothing alike.

    兩者之間沒有一絲相似之處,

  • So why would you think to combine them?

    那麼,為什麼會把它們混為一談?

  • Physicists didn't just decide to mash these things together out of no where.

    物理學家並不是隨隨便便 就將這些東西混在一起看,

  • Rather, they were led to the dual nature of the universe

    相反的,通過簡單的步驟,

  • through a process of small steps,

    它們被推導到宇宙的雙重性。

  • fitting together lots of bits of evidence, like pieces in a puzzle.

    配合上大量的證據,就像一個拼圖。

  • The first person to seriously suggest the dual nature of light

    第一個認真看待雙重性的人

  • was Albert Einstein in 1905,

    是1905年的愛因斯坦,

  • but he was picking up an earlier idea from Max Planck.

    但他的理論源於 馬克斯•普朗克早期的想法。

  • Planck explained the colors of light emitted by hot objects,

    普朗克嘗試解釋高溫物體發出的色光,

  • like the filament in a light bulb,

    像是燈泡的燈絲,

  • but to do it, he needed a desperate trick:

    但要做到這一點,他運用 一招看似無望的絕招:

  • he said the object was made up of oscillators

    他說物體是由振盪的粒子組成,

  • that could only emit light in discrete chunks,

    振盪的粒子只會發出特定顏色的光,

  • units of energy that depend on the frequency of the light.

    能量的大小由光的頻率決定。

  • Planck was never really happy with this, but Einstein picked it up and ran with it.

    普朗克從來沒有對這點高興過, 但愛因斯坦將它拿來運用並發揚光大。

  • He applied Planck's idea to light itself, saying that light,

    他運用普朗克的想法,認為光本身,

  • which everybody knew was a wave, is really a stream of photons,

    這大家都知道是一個波,其實是光子流,

  • each with a discrete amount of energy.

    愛因斯坦宣稱每個光子 都有一個單獨的能量。

  • Einstein himself called this the only truly revolutionary thing he did,

    愛因斯坦本人宣稱這是他 唯一真正做到的科學革命,

  • but it explains the way light shining on a metal surface knocks loose electrons.

    但它可解釋可光照射金屬表面 產生電子的現象(光電效應)。

  • Even people who hated the idea had to agree that it works brilliantly.

    即使憎恨這種想法的人 都不得不承認,它真的很管用。

  • The next puzzle piece came from Ernest Rutherford in England.

    接下來的拼圖來自英國的拉塞福。

  • In 1909, Ernest Marsden and Hans Geiger, working for Rutherford,

    1909年,歐內斯特•馬士登 與漢斯•蓋革為拉塞福工作,

  • shot alpha particles at gold atoms

    他們對金原子發射α粒子,

  • and were stunned to find that some bounced straight backwards.

    並震驚地發現, 一些α粒子會反彈向後飛。

  • This showed that most of the mass of the atom is concentrated in a tiny nucleus.

    這顯示,原子的質量集中 在一個很小的核中。

  • The cartoon atom you learn in grade school,

    在小學你看到原子卡通影片,

  • with electrons orbiting like a miniature solar system,

    原子的電子軌道就像一個微型的太陽系,

  • that's Rutherford's.

    這是拉塞福的原子模型。

  • There's one little problem with Rutherford's atom: it can't work.

    拉塞福的原子模型還有一個小問題: 它不能持續運轉。

  • Classical physics tells us that an electron

    古典物理學告訴我們,

  • whipping around in a circle emits light,

    繞圈運動的電子必定發出光(電磁波),

  • and we use this all the time to generate radio waves and X-rays.

    當我們發出無線電波和X射線時, 一直運用到此現象。

  • Rutherford's atoms should spray X-rays in all directions for a brief instant

    所以拉塞福的原子會短暫射出X射線,

  • before the electron spirals in to crash into the nucleus.

    在電子以螺線前進至 原子核之前就會崩潰。

  • But Niels Bohr, a Danish theoretical physicist working with Rutherford,

    不過,丹麥理論物理學家 尼爾斯•玻爾拉塞福與合作,

  • pointed out that atoms obviously exist,

    他指出,原子明明就存在沒有崩潰,

  • so maybe the rules of physics needed to change.

    所以也許是物理學規則需要修改。

  • Bohr proposed that an electron in certain special orbits

    玻爾提出理論指出電子 位於某些特殊的軌道,

  • doesn't emit any light at all.

    所以能不發出任何光線。

  • Atoms absorb and emit light only when electrons change orbits,

    只有當電子改變軌道時, 才會吸收和發射光,

  • and the frequency of the light depends on the energy difference

    而光的頻率則取決於軌道的能量差。

  • in just the way Planck and Einstein introduced.

    就這樣,普朗克和愛因斯坦起的頭,

  • Bohr's atom fixes Rutherford's problem

    玻爾的原子說修正了拉塞福的問題,

  • and explains why atoms emit only very specific colors of light.

    並解釋了為什麼原子 只會發出特定顏色的光。

  • Each element has its own special orbits,

    每一個元素都有其特殊的軌道,

  • and thus its own unique set of frequencies.

    因而其自身獨特的一組頻率。

  • The Bohr model has one tiny problem:

    玻爾原子模型有一個小小的問題:

  • there's no reason for those orbits to be special.

    說不出那些軌道特殊的原因是什麼。

  • But Louis de Broglie, a French PhD student,

    但法國的博士研究生路易•德布羅意,

  • brought everything full circle.

    為這一切都帶來完美的解答。

  • He pointed out that if light, which everyone knew is a wave,

    他指出如果光,這大家都知道是一種波,

  • behaves like a particle,

    行為像粒子,

  • maybe the electron, which everyone knew is a particle,

    比如說電子,這大家都知道是一個粒子,

  • behaves like a wave.

    行為也像波一般。

  • And if electrons are waves,

    如果電子也具有波動性,

  • it's easy to explain Bohr's rule for picking out the special orbits.

    就很容易解釋玻爾特殊軌道的規則了。

  • Once you have the idea that electrons behave like waves,

    一旦你想像電子的行為像波動,

  • you can go look for it.

    你就可以去尋找它的波動性。

  • And within a few years, scientists in the US and UK

    並且在幾年內,科學家在美國和英國

  • had observed wave behavior from electrons.

    都觀察到電子的波動性。

  • These days we have a wonderfully clear demonstration of this:

    至今我們已可以非常清楚的演示這一現象:

  • shooting single electrons at a barrier with slits cut in it.

    在拍攝個別電子通過狹縫的情形,

  • Each electron is detected at a specific place at a specific time,

    每個被檢測到的電子都是 在特定時間出現在特定位置,

  • like a particle.

    這像是粒子的行為。

  • But when you repeat the experiment many times,

    但是,當你多次重複實驗,

  • all the individual electrons trace out a pattern of stripes,

    所有的電子會形成干涉條紋,

  • characteristic of wave behavior.

    這是波動的行為特徵。

  • The idea that particles behave like waves, and vice versa,

    電子的行為像波又像粒子,

  • is one of the strangest and most powerful in physics.

    這是物理學中最奇特且最強大的一點。

  • Richard Feynman famously said

    理查•費曼說過一句名言:

  • that this illustrates the central mystery of quantum mechanics.

    這說明了量子力學中最神秘的核心。

  • Everything else follows from this,

    萬物皆遵循此一特點,

  • like pieces of a puzzle falling into place.

    於是最後一塊拼圖就定位。

One of the most amazing facts in physics is this:

在物理學最令人驚訝的事實就是:

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B2 中高級 中文 TED-Ed 電子 粒子 原子 軌道 發出

【TED-Ed】粒子與波。量子力學的核心奧祕--查德-奧澤爾。 (【TED-Ed】Particles and waves: The central mystery of quantum mechanics - Chad Orzel)

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    稲葉白兎 發佈於 2021 年 01 月 14 日
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