
Heat energy can travel through empty space - stambros
https://phys.org/news/2019-12-energy-space-quantum-weirdness.html
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eesmith
"Heat energy" here means "phonons", not "infrared light."

> for many years, textbooks told us that phonons cannot travel through a
> vacuum," said Xiang Zhang, the professor of mechanical engineering at UC
> Berkeley who guided the study. "What we discovered, surprisingly, is that
> phonons can indeed be transferred across a vacuum by invisible quantum
> fluctuations."

It's due to Casimir interactions.

