I'm reading this dissertion (PDF) by one Ryan Jeffrey McMillen and the following lept off the page and grabbed me by the eyeballs
The last two chapters in this section examine O'Neill's colonies by looking at them as inverted or hollow earths - mini-planets turned away from the frightening reality of a vast and ancient cosmos.Which reminds me of complaints that rockets are a phallic symbol, and the rejoinder that they are only because a vagina-shaped rocket is not aerodynamic. Perhaps an O'Neill habitat willl be turned inward because a rotating habitat with people, water and shrubs on the outside doesn't work so good.
