If computronium is of density equal to or greater than iron, physics wouldn’t need to be changed. Remove the core, replace it with a roughly spherical wad of perfected brain-matter, plus whatever structural supports are necessary to keep the crust in place, and Newton’s Shell Theorem says gravity would be the same. Add some electromagnets for the poles, and channel waste heat from the mechanisms inside to simulate volcanism where appropriate.
Even if computronium turns out to have lower density than iron, and for whatever reason it’s unacceptable to reduce surface gravity or transplant the luddites to an otherwise earthlike planet of correspondingly greater diameter, some of the core’s mass could be converted and the remainder compressed into a black hole. Again, shell theorem means there’s no difference from the outside.
If computronium is of density equal to or greater than iron, physics wouldn’t need to be changed. Remove the core, replace it with a roughly spherical wad of perfected brain-matter, plus whatever structural supports are necessary to keep the crust in place, and Newton’s Shell Theorem says gravity would be the same. Add some electromagnets for the poles, and channel waste heat from the mechanisms inside to simulate volcanism where appropriate.
Even if computronium turns out to have lower density than iron, and for whatever reason it’s unacceptable to reduce surface gravity or transplant the luddites to an otherwise earthlike planet of correspondingly greater diameter, some of the core’s mass could be converted and the remainder compressed into a black hole. Again, shell theorem means there’s no difference from the outside.