Diamond Lake

I'm reading A Fire Upon the Deep by Vernor Vinge (Goodreads) and in Chapter 35, page 365, they are talking about setting up a park inside a 200 meter diameter cavern that they have carved out of a giant diamond. The diamond is roughly cubical and measures about a thousand meters on a side. Don't ask me where they got it, probably found it out wandering around in the asteroid belt of the On-Off star system. This diamond rock, along with all their stuff, is floating around in space at L1 which sits them hanging in limbo between the planet and the star.

Now they are talking about putting a lake in this park, a park that will only have microgravity at best and I'm thinking how could this possibly work? If you leave it undisturbed and there is the least hint of gravity or centrifugal force, it should form a pool on one side of the cavern, but you so much as breath on it you're liable to get Tsunami. Mr. Vinge wants them to drop a bunch of micro-widgets into the lake and the, through the power of modern computers, will counteract all the wrong impulses in the water and force it to behave. Okay, Vern, I think you've stepped over the line here.

Maybe I'm being too hasty. Every seen the ripples generated in water when a strong audio sound is applied? So maybe having a battalion of micro-actuators could be made to counteract any activity on the surface. But we've still only got micro-gravity to pull the water back down. I could see this quickly getting out of control. The only solution I see is start pushing this giant rock with a rocket, which could happen, they have some big rockets in this story. Well, that is until someone invents some kind of gravity control, which I don't think is ever going to happen. Centrifuges, rockets and mass are going to remain the sole methods of affecting gravity now, forever and always.