[Copy pasta from IMDB]
How come when the van drives off the bridge in Level One, the dream is in zero gravity in Level Two, but the dream in Level Three has perfectly normal gravity?
Firstly, we know that the effects of one level have stronger effects on their proceeding level than any after that which is why Saito feels less pain from his gunshot wounds as he gets deeper. Level three is therefore less likely to feel the effects of level one. Secondly, the dreamers in Level one (Specifically Arthur, because Level Two is Arthur's dream) are feeling a zero-gravity drop which causes Level Two to lose gravity. However the dreamers in Level Two, (Specifically Eames because Level Three is his dream) aren't FEELING zero-gravity, they're EXPERIENCING a lack of gravity. It's the movement that affects the dreamer not the experience and thus, because the dreamers probably can't feel this weightlessness when they're asleep, it won't affect their dream.
Ok that made perfect sense! 8D
