喜樂美語

核心畫面

One way to picture it: a single sharp push from behind. Not a steady wind, not a plan — one shove that arrives and moves you before you have decided anything. Everything this word means comes back to that one push travelling through something.

背後突然來的一下推力。不是持續吹的風，也不是想好的計畫——就是「啪」一下，推了你一把，你已經動了才回過神。這個字底下…更多收起背後突然來的一下推力。不是持續吹的風，也不是想好的計畫——就是「啪」一下，推了你一把，你已經動了才回過神。這個字底下的三個意思，說穿了都是同一下推力在不同地方跑：跑在心裡就是衝動，跑在神經或電線上就是脈衝，跑在一整個現象背後就是推動力。

From the word’s history

From Latin impulsus, the past participle of impellere 'to push against, drive forward' (in- 'against, into' + pellere 'to push, drive'). The same root sits inside impel, propel and compel — all of them are pushing words.

來自拉丁文 impulsus，是 impellere（往前推、驅使）的過去分詞：in-（向、往裡）＋ pellere（推、驅趕）。同一個 pellere 也藏在 impel（驅使）、propel（推進）、compel（迫使）裡——這一整家子都是「推」的字。知道這件事之後，impulse 三個意思就不用分開背了：它們共用同一下推力。

Wiktionary, 'impulse' / 'impel' (from Latin impulsus, past participle of impellere, from in- + pellere 'to push, drive')

Three branches

心裡那一下推力

推力發生在自己心裡：來得快，動作跑在思考前面。

sudden urge · noun · C2

A sudden strong wish to do something, without stopping to think if it is a good or sensible idea.

衝動

沿著線傳的那一下

同一下推力，但這次跑在身體或機器裡：短、有方向、一個接一個。

electrical signal · noun · C2

A short electric signal that moves in one direction along a nerve or a wire.

脈衝

背後推著事情走的力量

把推力放大到一整件事情或一整個時代背後：不是某個人一時的念頭，而是推動某類行為的那股力量。

driving force · noun · C2

A reason or aim that causes a particular kind of activity or behaviour.

動力

原始詞典資料4 筆記錄

以下是外部詞典記錄的用法，原文照列，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。

impulsenoun/ˈɪmpʌls/

  • 1

    A thrust; a push; a sudden force that impels.

    • c. 1715-1716, Samuel Clarke, letter to Gottfried Wilhelm Leibniz All spontaneous animal motion is performed by mechanical impulse.
  • 2

    A wish or urge, particularly a sudden one prompting action.

    • The impulse to learn drove me to study night and day.
    • When I saw the new book, I couldn't resist the impulse to browse through it.
  • 3

    natural-sciencesphysical-sciencesphysicsThe integral of force over time.

    • The total impulse from the impact will depend on the kinetic energy of the projectile.

impulseverb/ˈɪmpʌls/

  • 1

    To impel; to incite.

    • With that force so impulsed and prest they are carried under the deepe Ocean.

資料來源：英文維基詞典 English Wiktionary（CC BY-SA 4.0）。 原文照列，未經改寫。