Understanding time dilation (vid) 
This is the most intuitive conceptualization of Einstein's special theory of relativity that I've seen. Random memory: I remember myself a friend trying to explain this to another friend many years ago back in high school and it wouldn't take. It was a really frustrating hour. In the end, I think he got it sooner than we realized, but he was having too much fun seeing how pissy we were getting.
http://www.wimp.com/timerelativity/
This is the most intuitive conceptualization of Einstein's special theory of relativity that I've seen. Random memory: I remember myself a friend trying to explain this to another friend many years ago back in high school and it wouldn't take. It was a really frustrating hour. In the end, I think he got it sooner than we realized, but he was having too much fun seeing how pissy we were getting.
http://www.wimp.com/timerelativity/
