decay energy

He found that the length of time it takes a sound's echo to decay is determined by the absorption of the sound's original energy by surrounding material.

他发现，声音回声衰减的时间长短取决于周围物质对声音原始能量的吸收。

"These creatures get their energy from sources we never imagined," McKay exclaims. "the South African extremophile bacteria are powered by the radioactive decay of unstable atoms in the rocks."

“这些生物从一个我们从未想到的来源获取能量，”McKay惊叹，“南非的极端微生物细菌吃的是岩石里不稳定原子衰变时的放射能。”

Hawking showed that black holes radiate energy and decay over time (the aforementioned Hawking radiation).

Hawking说明了黑洞向外辐射能量并随着时间衰减(前文提到的Hawking辐射)。