[9214]

There's a plethora of air-gap malware studies from Ben-Gurion university [1], abused channels range from thermal, acoustic, optical, to classic TEMPEST.

The interesting thing is that there's no escape from such covert attacks, since machines are bound by the laws of physics that demand energy dissipation and generation of noise, heat, etc. If it leaks, then it computes.

[1]: https://cyber.bgu.ac.il/air-gap/

[blacksmith_tb]

Shouldn't that be the other way around? Plenty of things leak heat (like cooking dinner) that don't do any computation?

[goldenkey]

The quantum of action, which a layperson can consider as the smallest possible state change, is actually Planck's constant.

https://en.wikipedia.org/wiki/Planck_constant

All energy refers to is an amount of state change that is occurring every second that some quantity of energy exists. That's why action has units Energy x Time. You can divide by time and you get Energy = Actions per Second, kinda like APM in Starcraft..

https://en.wikipedia.org/wiki/Action_(physics)

Principle of least action is really the principle of "least change."

In summary, computation is happening -- but most of the computation that energy does while held as mass/matter is cyclic processes (aging.) Not anything interesting, at least to me or you. Unless you like https://en.wikipedia.org/wiki/Radiometric_dating

[9214]

Maybe. Or maybe they do but we don't know it ;)