NOTES
Newton's gravity is a theory about the interaction between two particles; the electric and magnetic forces were initially described the same way. Faraday, however, came up with a model of electromagnetism as lines of force pervading space. Though this model was flawed (space is not filled with gears), it inspired Maxwell's invention of a completely new way of modeling interactions - the field concept, which is the basis of all modern physics theories, from general relativity to quantum mechanics.