I understand the the motion of charges in a particular direction constitutes a current, and from my understanding, the more charges you have flowing in the same direction, the stronger the current. Are there significantly different properties that arise with strong current? After watching this video: http://www.youtube.com/watch?v=W1TMZASCR-I I was wondering if there is an analogous way to sync the movement of charges. It seems like the board on which the metronomes move "coaxes" the metronomes to sync up. What kind of device or naturally occurring object, if any, could do the same for charges? Magnets come to mind, since they move charges, and charges can move magnets, but I'm not sure about the relative forces that would be needed to keep in proportion. Thoughts?