To illustrate this quantitative relationship: imagine a positive charge carrying 1 coulomb of electricity moving along the positive x-axis at velocity V. How much magnetic field and gravitational field does it produce? How are these fields distributed, and in which direction do they point? If we place an insulating object with a mass of 1 gram 1 centimeter away from the charge, how much force does it experience? If we move this object, does the force change? If the force matches our theoretical predictions, the experiment succeeds, and the theory is validated.