完かん全ぜん真しん空くう

か

ん

ぜ

ん

し

ん

く

う

Meanings

1

Technical term in physics and engineering for a space entirely devoid of matter, or an ideal state with zero pressure.

非ひ

常じょう

に

難むずか

しい

。

Creating a perfect vacuum is technically extremely difficult.

理り論ろん上じょう、完かん全ぜん真しん空くうでは音おとは伝つたわらない。

In theory, sound does not travel in a perfect vacuum.