"It sounded like you were saying that for weird reasons light would filter down into the caverns so plants would grow."

"Ah, no, just that it won't get unliveably hot in places on or in the side of the cylinder which the sun passes close to."

"Ah. How far down does the sun go?"

"Two surface-diameters."

"Is the bedrock unusually structurally stable for a rock, or is it holding itself together in a cylinder by special-case physics such that I still need to do all my engineering math on how big and how deep to put caverns very carefully?"

"There's a core made of indestructible celestum - or locally believed to be indestructible, anyways - running down it, so I don't think you could topple us by accident but I expect there are other outcomes worth working to avoid."

"Oh, well, how big is the celestum part, I need to know for geographical planning reasons - the other rock also matters, though, because there's a whole world on top of this thing and that is presumably pretty heavy and creating a cavity underneath I'd better be sure the ceiling will stay put under a wide range of possible stresses."

"It fluctuates by depth; there's some that sticks out a bit onto the surface at the center which is about this big."  She holds her hands at about a flagpole-sized circumference.  "But there are also less-central veins of it, some but not all of which connect back to the core.  Stars in general have mapped out a fair bit of it but not in a way I expect to be easily translated to a form useful to you."

"I guess I'll conjure whatever cross-section I have in mind..." He tries making celestum, though he expects it not to work.

It doesn't.

"There's a ring of cold celestum under Antarctica, like what Polaris is made of, so you'd probably want to start at least far enough down to be mostly out of its reach, too."

"Are there other celestum subtypes or just cold and not-especially-cold? Is it conductive? Is it nonbioreactive? Can things adhere to it if it's exposed after excavation?"

"The sun, moon, the physical components of stars, and the shell of the universe are also made of different kinds; it's more of a category than a specific substance.  I don't know most of the answers to those because I don't imagine that anyone has tried to run electricity through the sun or whatnot - well, successfully - but I don't see why you couldn't attach things to the less destructive varieties."

"Huh, okay. There were some holes in the slice I conjured before..." Let's have a plastic model of the first five thousand miles down of cylinder, translucent so he can see caverns and gaps that might not all be missing celestum.

Here is a cylinder, not quite half as tall as it is wide, with a hole down the center that starts out almost invisibly small at the top and widens greeblishly out to the width of a finger or two.  There are lots of speckly holes dotting the model, and a really big, much smoother torusish-funnelish one ringing around under Antarctica as expected.  There are also some swirl-shaped holes here and there - most smaller than the torusish; some smoother, some kind of scaly in the same way as the core; some connected to it and some separate.  The biggest one curls under much of the western part of the Pacific Ocean and the eastern part of Africa before getting cut off by the bottom of the model.

"Okay, there are existing caverns in the cylinder so I don't have to worry about excavating and whether that's safe for a while."

"Good news for the Cam Empire or the Resurrection Nation or whatever you should choose to call it."

"I don't know if that many resurrectees will choose to live there! Presumably lots of people are mostly motivated to be resurrected so they can go back to their lives and I will wind up freeing up space for them by taking immigrants from elsewhere."

"I imagine that's true of the long run, as the recently dead keep deciding not to stay that way, but in the short term I do expect a fair number of star clouds and a fairer number of star cloud bodies to want it, though maybe I'm more of an odd gull than I realize.  - It's a good thing you can do houses, now I'm imagining somestar hundreds of souls big all wanting to live in the same enormous apartment."

"Hundreds of souls would want an entire apartment building!"

"Well, it could be a duplex."

"Maybe when I next get high if I meet any clouds that are considering it I'll tell them to design themselves a home. I should probably ask Nudge for psychic course-correction soon anyway."

"Good thought.  Do you want me to come with?  At some point it would probably be good to test what happens to embodied clouds on omnilol but of course it doesn't have to be now."

"Huh, your call. Or I guess the call of how much I have on hand left." How much has he got.

Plenty!

"I believe I shall if the option's available."

"'Tis!" he says, passing her the container after pouring himself some. He settles in comfortably (lap Cricket and all), and down the hatch it goes.