I have heard several times of the concept of "thermal superconductivity" (As opposed to "electrical superconductivity"), but I am unclear on exactly what that could mean. It turns out to be really hard to google, since everything comes up with thermal effects on electrical superconductivity (critical temperature and all that).
So, given that electrical superconductivity is when electrical current can flow without energy loss, what exactly is the corresponding concept for thermal superconductivity? Given that flows of heat are, well, already composed entirely of heat, what energy-loss mechanism is there that could be minimized? Or am I just completely missing the point?