Frame of reference.... Ok here's a question inspired by relativity and frames of reference. In a funfair, there are two carousels (merry-go-rounds), each 4 meters in diameter and their centers 5 meters apart. They revolve with the same angular velocity, but in opposite directions. We have two twins P and Q on these carousels. Going round the carousels they pass each other several times. Later, when they are sitting down and enjoying their meals, P tells Q that her carousel was faster because she always seemed to overtake Q. Q said he also felt exactly the same thing - that his carousel was faster! What's happening?! Why does each one feel that he/she is faster than the other?