Reading the Arthur C. Clarke novel: "Rendezvous with Rama"; something keeps nagging me about the descriptions of their experience inside the ship they encounter, which is a huge, rotating, hollow cylinder. It's rotation makes a sort of "pseudo-gravity" by way of centrifugal force. The issue I'm having relates to this "gravity" being described as gradually increasing the further you get from the axis of spin. My mind keeps telling me that, in space, you would be weightless anywhere within the hollow parts of the cylinder (spinning or not), and only if you made yourself a part of it's matter (by holding onto the sides and adopting the spin, for instance) would you experience the "gravity". The ship has an atmosphere built up inside it, though, which would provide some matter that would eventually adopt the spin and therefore be thrust from the center axis. But I would think the forces you experience having just left the weightlessness of the axis would be limited to what little of the spin you would adopt based on the friction of the air around you - until you reached the spinning outer wall, that is. Am I totally off base? If so, why would you feel the centrifugal pull of a spinning body you weren't actually touching? The main thing that caused me to wonder is the flying bicycle trip one of the crew takes to the other side of Rama. He experiences a greater centrifugal pull/push the further he gets from the axis (the only place he is said to experience actual weightlessness). But, without being a part of the spin (which you wouldn't be unless pushed by some form of matter already spinning - correct?) why would this happen? Would just the air of an atmosphere be enough to act on you in this manner?