“pressure lower than interstellar space”
I’m intrigued by the idea that we may be creating the profoundest sustained vacuums and lowest temperatures in the entire universe, but there’s bound to be something somewhere that outdoes us humble humans even in those things. Or maybe not.
People look at those large concrete tubes sprawling over the desert and assume that the concrete is instrumental in maintaining the circular shape around the enclosed vacuum. Actually that’s not the case (except for protection from environmental impingement by things like roving vehicles and wayward bullets). Rather it is the 14 gauge (or whatever) curved stainless steel sheet metal keeping the atmosphere out.