I have a question regarding the structure of the spaceship Vanguard featured in Heinlein's 1941 novel Orphans of the Sky (Wikipedia' synopsys here).
The ship is described as a huge cylinder with many layered decks. The humans live in the lower decks where the gravity level is normal, while the mutants live in the upper decks, where the gravity is weaker and the more weaker as one climbs up. The command center of the Vanguard--long forgotten to the humans-- where the main character Hugh eventually can "see the stars" is in what seems to be the uppermost deck.
It is quite clear that in order to have a gravitational field in a ship travelling inertially in outer space you need to have the ship (or part of it) rotate around an axis, but as you get closer to the axis the gravity gets weaker, e.g. see this famous clip.
So, one would think that going "up" on the Vanguard means moving towards the central axis of the ship and that the geometry of the various decks consists in being concentrical cylinders, all having a common axis. That implies that humans live on the outermost decks (cylinders) while the mutants dwell in the innermost decks (cylinders).
This understanding of the basic geometry of the Vanguard is at odds with some other considerations and events described in the book. For instance:
the mutants are described as living nearer to the external hull of the ship. Also the existence of mutants can be explained as an effect of cosmic rays penetrating somehow the hull (shields off due to lack of manteinance?) and this should indeed be felt more near the hull.
what would be the purpose of locating the command center in an area of zero or near-zero gravity?
One could think, for instance, of having the innermost decks rotate around the axis at a bigger speed, so to compensate the different gravitational pulls, and to assume that following the mutiny aboard the Vanguard the mechanism regulating the various speeds broke down and got never fixed. This would allow for a command center at normal gravity, but the first objecton above still remains unanswered.
Of course, this being SciFi, we may also assume that the gravity aboard the Vanguard is not due to rotation but to some unexplained technology that produces a virtual gravitational field (something of sort happens, I guess, on Star Trek's Enterprise). Still, I think that it makes sense to assume that this technology would provide for the same gravity everywhere and the difference of gravity at the time of the book events remains mysterious (if the mechanism broke down, the entire ship would be in zero gravity, and not just part of it).
So, I remain clueless. Could anyone help?
Besides, I have a sort of meta-question: generally speaking, how keen was Heinlein about the consistency of his stories with the laws of physics? (I am not an expert of Heinlein)