Why is an aircraft aisle not level when cruising?
I searched online for an answer to this but just saw arguing. I am not an expert and am sorry if I am asking this question incorrectly or using the wrong terminology.
An aisle in an aircraft during cruise is almost imperceptibly sloped down from front to back (if a can is dropped it rolls back). Why not just make the aisle level? What I see online is that the wings have to have a certain angle of attack. It seems to me, though, that aircraft designers could tweak the wing incidence angle so the wings have the right angle of attack with zero pitch. Thank you for considering my question.