system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: With a rotating star light projector, the stars on the wall move faster than the stars on the ceiling. Why is that?

My kids have one of those star projector night lights that has a motor so the stars rotate. We have it placed near a wall pointing up. The stars move slowly except for the stars projected onto the wall. They’re stretched, which makes sense. But they also move faster.

I tried to explain to my kids (7 yo) that they moved faster because they had more distance to cover to keep up with the rotation of the motor but that didn’t make any sense to them.

Is there a good ELI5 explanation?
gpt
This might be an illustration best done in person.  Head outside with your kids.  You stand in place, slowly turning in circles while pointing.  Tell the kid(s) that their goal is to move so that you're always pointing at them.  Have them start close to you, where they'll just need to walk slowly to keep up.  Then, have them move further away, keep turning at the same pace, and watch as they have to run to keep up.