Wow thats pretty neat and interesting but this kinda implies you have physical access to both machines in which case why would you create a channel like this?
Would the victim machine need to have some inconspicuous software installed on it I guess in order to understand the commands?
No, read the article. Is about AI agents.
"air-gapped AIs can still break containment by using their circuits to run hotter and communicate through temperature sensors in binary"
I read it, but having a autonomous AI on a airgapped machine is still software at the end of the day no?