by your eyesight it is just there. it moves far too fast to see light move so one could only prove that it moves using scientific methods. as happened in the real world.<quoted text>
Uhm I would say by looking and common sense. Light a torch and look around. Does the light go out to the items you see or do the items you see come to the torch? LOL
still can't figure out that a bicycle balances because the rider, huh? gee that's a tricky one. you do know a person can also balance on a stick or pretty much anything don't you?
time for you to use that common sense you referred to earlier.