What Is a Clock?

i'm going to show you the approach of how julian barber has addressed this question of what is aclock? Ok? So, ah, so first, while going back a little bit to he john weelers er statement about time is so defined that motion looks simple. But then eimstein's generaltivity came and showed that in his theory, the everything about mercury's orbit is fully understood. So then that motion doesnt no longer look complicated. Do you see what i'm trying to saywe when i say simple verseis complicated? Yes.