振動

• Reading: しんどう
• Romaji: shindo
• Kanji breakdown: 振 (shin) — shake, wave | 動 (do) — move, motion
• Pronunciation: /ɕin.do.ɯ/

Meaning

Vibration; oscillation; tremor. A rapid back-and-forth movement around a central point.

A versatile physics term applied to sound waves (音の振動), earthquakes (地震の振動), mechanical engineering, and quantum mechanics (零点振動). Key collocations: 固有振動数 (natural frequency), 強制振動 (forced vibration), 共振/共鳴 (resonance). Also used colloquially for a buzzing phone (スマホが振動する).

Examples

1. 地震が発生すると地面の振動が建物に伝わり、構造物に大きな力が加わる。 When an earthquake occurs, ground vibrations are transmitted to buildings, exerting great force on structures.
2. 音は空気分子の振動が波として伝わる現象であり、媒質がなければ伝播しない。 Sound is a phenomenon in which the vibration of air molecules propagates as waves; it cannot travel without a medium.
3. 橋の固有振動数と外力の振動数が一致すると、共鳴現象が起きて崩壊する危険がある。 If a bridge's natural frequency matches the frequency of an external force, resonance occurs and there is a risk of collapse.

Usage Guide

Context: physics, engineering, seismology, acoustics

Tone: technical

Origin & History

Compound of 振 (shin) meaning 'shake, wave' and 動 (do) meaning 'move, motion'. Together they describe repetitive shaking movement, mirroring the Latin vibration from vibrare (to shake).

Cultural Context

Era: Modern

Generation: All ages

Social background: Universal