Yeah, in the real world there is no upside down in space.
But if you look at Star Wars or especially Star Trek, you will notice that the ships always are like horizontally aligned. It is a normal thing in movies to make “it look good”.
Yeah, I’ve noticed that. It’s become a pet peeve of mine.
Why?
Can you imagine how hard it would be to tell a story if spaceships didn’t stay “upright” most of the time. It’d also be very disorientating to watch. It would make scientific sense, but in cinematically it would be an absolute mess.
(Also SW is basically just Middle-Earth in space. It’s not exactly known for its scientific accuracy.)
It would be nice to see them play with the idea in Star Wars once in a while though.
If you’ve never seen First Contact, Picard and company are walking on the underside of the saucer section.
The starbase in the new Trek movie really plays with the idea that up and down are all dependent on where you’re standing. The final fight at the end had me wondering what a zero gravity lightsaber battle could be like.