Hi We've just begun studying magnetic force in school. Our teacher told us to explore the possibility of a paradoxical situation as F=qBv From different inertial frames, the apparent force will be different, won't it ? Our teacher told us that Einstein's theory of relativity solved the paradox, but it's not in our syllabus. So can you guys tell me how theory of relativity solves the paradox by including the actual details of the theory as little as possible ? And while you're at it, can you tell me why does a magnetic bottle cause reversal of the direction of helical motion ? Thanks a lot.