I have never in my life taken a physics course, so this may be obvious to other people who have. Parts of this article explaining relativity using only words with four or fewer words make sense to me and parts don’t. The stuff near the end is really hard for me to understand, but I figure it’s hard for most people to understand. What frustrates me though is the bit about Bert and Dana (when Bert is on the bus). I don’t understand the declaration that, since he’s moving, Bert would see the rocks come down at different times if they appeared to come down at the same time from Dana’s perspective. Maybe it’s true, but I have zero real-world experience of anything like that so I don’t get it. Does that really happen? Is there a way to experience it?