noun
microwave background radiation
Technical term in astronomy and cosmology, referring to the cosmic microwave background (CMB).
マイクロ波背景放射はビッグバンの名残と考えられている。
The microwave background radiation is thought to be a remnant of the Big Bang.
Longer, more explicit term for cosmic microwave background radiation; マイクロ波背景放射 is a shorter variant.
Compound of マイクロ波 (microwave) + 背景 (background) + 放射 (radiation), a calque from English 'microwave background radiation'.