Corrected entry: The spacecraft Discovery has a rotating centrifuge-room that the astronauts use to avoid the detrimental effects of prolonged weightlessness. We see the rotation when Dave first enters the room and again later when he and Frank re-enter the room after inspecting the AE-35 Unit. But by Newton's laws the torque on the centrifuge must be countered by an equal anti-torque, so the surrounding body of the ship ought to be counter-rotating to conserve angular momentum.
Corrected entry: While Dave Bowman & Frank Poole are in the pod bay they lean against the workbench much as anyone would on Earth, yet the pod bay is a weightless environment.
Correction: Already posted and corrected. Microgravity doesn't paralyse your muscles. You'd lean on things just the way you do under normal gravity.
Corrected entry: The first time Dave is shown running around the room on the ship, in the roomwide shot he runs past the three hibernating crew, then the two empty beds. In the following chase shot on his back, he passes them in reverse order.
Correction: The scenes aren't necessarily continuous time, but a collage of shots of his exercise period. He even reverses direction between two of the shots so where the pair of sleeping crew was on his left, they are now on his right.
Corrected entry: During the trip to the Moon, the spacecraft's captain makes a friendly call on his passenger, Dr. Floyd. Although they are weightless, the captain leans onto Floyd's chair under his full body weight.
Correction: Microgravity doesn't paralyse your muscles. Someone used to 'weightlessness' would be able to pose in such a manner simply by leaning at the right angle.
Correction: The centrifuge began rotating in earth orbit. The counter-rotation would have been corrected by whatever structure holds the ship in place while being built. If this didn't happen, then the bad momentum would be stopped by discovery's roll-mode attitude thrusters.
Faye_Kane