Above left: Bowman moves across Discovery One's emergency airlock at a high rate of speed, after 'ejecting' into it from his EVA pod. Note the lighting in the airlock, and the alternating white-black patterns on the walls. Above right: Bowman disconnects HAL. Note the numerous, colored 'slits' of light. The point is that the patterns of light Bowman sees in these two scenes, form part of the source for what he physically sees as he moves through the stargate. It's as if while he's in the stargate, he's seeing (somewhat distorted) 'after-images' of some of the things he had seen shortly before the stargate's beginning.
Top left: Bowman, along with the alien life force inhabiting his body, is about to exit Discovery One near Jupiter. The monolith is floating nearby. Top right: Bowman's physical movement through the stargate is actually movement through a wormhole connecting Jupiter space with Earth space. A wormhole is a hypothetical feature of spacetime that would be, fundamentally, a "shortcut" through spacetime. When Bowman moves through the wormhole, he is taking a shortcut between Jupiter space and Earth space, and he is also going backward in time - the wormhole connects not only two different regions of space, but two different times as well. Evidently, the aliens have the ability to create wormholes. Above left: Once Bowman is near the Earth's surface, he sees blue sky and clouds. Above right: Shortly after this, he sees some rock formations.
