"Why, Jubal, it wouldn't take the Old Ones to do it.  It merely takes a certain fundamental knowledge of physics, how matter is put together - and the same sort of control that you have seen me use time and again.  Simply necessary first to grok what you want to manipulate.  I can do it unassisted, right now.  Say a piece near the core of the planet about a hundred miles in diameter - much bigger than necessary but we want to make this fast and painless, if only to please Jill.  Feel out its size and place, then grok carefully how it is put together-" His face lost all expression as he talked and his eyeballs started to turn up.