暗黒エネルギー

• Reading: あんこくエネルギー
• Romaji: ankoku enerugi
• Kanji breakdown: 暗 (an) — dark, hidden; 黒 (koku/kuro) — black; エネルギー (enerugi) — energy (loanword)
• Pronunciation: /aŋ.ko.kɯ.e.neɾ.ɡiː/

Meaning

Dark energy; the hypothetical energy permeating all of space that is thought to be driving the accelerating expansion of the universe.

A hybrid compound of the Sino-Japanese 暗黒 (darkness) and the katakana loanword エネルギー (energy, from German Energie). Dark energy is estimated to constitute about 68% of the total energy content of the universe. The term entered Japanese scientific vocabulary in the late 1990s following observations of accelerating cosmic expansion. It appears alongside 暗黒物質 in cosmological discussions and is commonly explained in contrast to ordinary matter and dark matter.

Examples

1. 宇宙の膨張が加速しているという観測結果は、暗黒エネルギーの存在を示唆している。 The observational result that the expansion of the universe is accelerating suggests the existence of dark energy.
2. 暗黒エネルギーと暗黒物質を合わせると、宇宙全体の約95パーセントを占めるとされる。 Dark energy and dark matter together are said to account for approximately 95% of the entire universe.
3. 暗黒エネルギーの性質を解明することは、宇宙の最終的な運命を理解する鍵となる。 Elucidating the nature of dark energy is key to understanding the ultimate fate of the universe.

Usage Guide

Context: cosmology, astrophysics, theoretical physics, science communication

Tone: technical, academic

Origin & History

Late 20th-century scientific coinage. 暗黒 (ankoku) carries connotations of the unknown and invisible, chosen to parallel 暗黒物質 (dark matter). エネルギー is the standard Japanese rendering of the German/English 'energy'. The compound was coined as cosmologists sought terminology for the mysterious force behind cosmic acceleration.

Cultural Context

Era: Modern

Generation: Adult

Social background: Educated