[Obiewahn (OP)]

What is the latest thoughts on what I believe is called the 'original charge' problem. That is why do fundamental particles have charge and where does it come from?

[Vern]

I don't think that question is solved in current mainstream particle theory.

Maxwell's equations describe electromagnetic fields and predict the wave action that we see. When the wave moves in a straight line, positive and negative charges balance giving a net charge of zero for a photon. I have a speculative prediction that a photon moving in a bent path would produce an electric charge. However, there is not yet experimental evidence of this.