I need a demonstration for the following topics: Time Dilation Special Theory of Relativity Twin Paradox So far, I plan on explaining the twin paradox by starting off with rolling a ball off the table and have my teacher catch it. Then I'll question him why he caught it and would it have fall to the ground if he didn't interefere. Basically, that will be able to introduce the class to the idea of a paradox. How should I start with a demonstartion for time dilation and theory of relativity? Something along the lines of the twin paradox is perfect.