What really is the electrical charge? Where did it come from?
The standard model of particle physics offers no answers about the causes of anything. Instead, it only offers a mathematical model of the effects. The same goes for string theory. My own Fractal Foam Model of Universes is not yet fully developed. It offers a basic framework in which all the forces may some day be fully explained. It gives a framework for explaining why each of the fundamental particles is what it is, but the specifics are beyond my meager mathematical ability. The underlying cause is that the ether has a foamy structure which is filled with a uniform background noise of pressure waves (aka dark energy). The pressure waves impart momentum to shear waves, and the shear waves either brighten or dim the background of pressure waves from the perspective of other shear waves. Consequently, shear waves can attract or repel one another and even orbit one another, thus converting their energy to rest mass. The forces between shear waves depend on their distance, phase, polarit