1. The problem statement, all variables and given/known data I don't understand why it is that by rubbing things together things develop charge, whereas when you just leave them close together they become discharged. What is it about the rubbing that acts as a mechanism to allow charge to flow? Isn't it the case that when rubbing doesn't occur the charges reverse their flow? 3. The attempt at a solution I understand that by rubbing things together electrons transfer to the one with more electron affinity. I also understand that friction is primarily an electric interaction. I think it may be some sort of heat driven thing, whereby heating the surfaces you allow electrons to have more energy to liberate. However, I am not sure, and I can't seem to find anything about it in my textbooks. What confuses me most is that when not rubbing them together the charge dissipates into the air, or back between the substances.