Like other great inventions, the discovery of electricity took thousands of years, as it was difficult to develop the right theory to explain the phenomenon. Physicists have combined magnetism with electricity, trying to figure out how these forces can attract objects, cause numbness in body parts and even cause fires. There were three main facts of the electrical forces that led scientists to invent electricity: Ancient Egyptian doctors knew about the electrical discharges that were generated by the Nile catfish...