真空

• Reading: しんくう
• Romaji: shinkuu
• Kanji breakdown: 真 (shin) — true, genuine | 空 (ku) — empty, void
• Pronunciation: /ɕin.kɯ.ɯ/

Meaning

Vacuum; a space devoid of matter. A state in which gas pressure is significantly lower than atmospheric pressure.

In physics, a perfect vacuum contains no matter at all, though in practice only near-vacuums are achievable. Key collocations: 真空状態 (vacuum state), 真空ポンプ (vacuum pump), 真空管 (vacuum tube). In everyday Japanese, 真空パック (vacuum pack) is a common compound. Used figuratively in 権力の真空 (power vacuum).

Examples

1. 宇宙空間はほぼ真空状態であり、音波は伝わらない。 Outer space is nearly a vacuum, and sound waves cannot propagate through it.
2. 真空ポンプを用いて容器内の気圧を下げ、沸点の変化を確認した。 A vacuum pump was used to lower the air pressure inside a container to observe changes in boiling point.
3. 真空中では空気抵抗がないため、重い物と軽い物が同時に落下する。 In a vacuum, there is no air resistance, so heavy and light objects fall simultaneously.

Usage Guide

Context: physics, engineering, space science, everyday products

Tone: technical

Origin & History

Compound of 真 (shin) meaning 'true, genuine' and 空 (ku) meaning 'empty, void'. Together they mean 'truly empty space'. The concept was introduced to Japan during the Edo period through Dutch-influenced natural philosophy.

Cultural Context

Era: Edo–Modern

Generation: All ages

Social background: Universal