zlacker

Probably orders of magnitude better than hard vacuum, though.

>>LeifCa+(OP)
For conductive cooling, sure.

But for radiative cooling, vacuum with a clear view of the night sky is orders of magnitude better.

>>LeifCa+(OP)
Their point is sure, you locally dump the heat. Where does it go then? There's not ground water to act as a sink so you're stuck with basically a big regolith insulator, and there's barely any atmosphere, so you're back to the black body of the ground with extra steps and a large local sink. That sink isn't infinite when you're talking even house scales, much less thermal scales of a large datacenter. Cooling works on earth because the atmosphere moves the heat.

>>LeifCa+(OP)
The regolith is 0.004W/m2K. Less than aerogel. Less than an open vacuum! Ouch!

Although the regolith is only 4-5 meters thick, so you could probably just go under it and see what the subsurface is like with regards to conductivity.