理想的な黒体はまっくろくろで放射率が1だよ。https://ja.wikipedia.org/wiki/%E9%BB%92%E4%BD%93
まっくろくろは語弊がある。室温の理想的な黒体は可視光線で見るとだいたいまっくろだよ (むずかしくなった)
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