fallsfromtrees wrote:JeffEngel wrote:I seem to recall that the access tunnel is normally kept full of nitrogen too. So you'd have to hold your breath, and that's quite a hike.
So yeah, who goes there, stays there.
I believe that is a reference to the fact that the cave was filled with nitrogen until Nimue awoke for the first time. I don't think we have any textev either way since that time.
Actually, Merlin didn't see any reason to pump in
any oxygen until Sharleyan made her visit to the cave so the medical computer could make sure her pregnancy was going well.
“Anyway,” Merlin went on after a moment, his tone deliberately brighter, “after they tucked me away, they filled the entire complex with an inert atmosphere. Which means there wasn’t really anything down here that a flesh-and-blood human being could have breathed. But Owl’s got the environmental plant up and running, so there’s going to be plenty of air when we get there.”
“Well, that’s a relief,” Sharleyan said dryly, wondering exactly what an “inert atmosphere” was.There's certainly no reason to
keep oxygen around, giving it the opportunity to oxidize anything it can nibble on, so I've always assumed that Merlin had OWL expel the oxygen from the cave after Sharley's visit, so it's had an inert atmosphere ever since. Granted, that's quite a
lot of atmosphere to scrub given the size of the cave, but the equipment to do it is already there, so there's been no reason to maintain a breathable (and corrosive) atmosphere when there's no one there who needs it.
The tunnel is separated from the cave by airlocks on both ends. As far as we know the tunnel's atmosphere continues to have a nitrogen atmosphere, which is easy enough to maintain by having it over-pressurized.