system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does the body vomit when spatially disoriented? What benefit is there from losing your lunch when the floor is moving?
gpt
The sensation of "motion sickness" is really just your brain getting conflicting information from your sense of sight and your sense of balance. Surprisingly we use our sight quite a bit to help our inner ear. For example, think of how it's harder to balance a bicycle if you look down rather than straight ahead.   One theory I've heard as to why this causes us to vomit is that this motion sickness, or the sensation that the room is spinning, is a common side effect from eating toxic materials and poisons. For our evolutionary ancestors, they might accidentally eat something like poisonous mushrooms. The toxins cause motion sickened and throwing up may be your body trying to get rid of something dangerous you ate.