Hi Robin > In order to flip the charge, you probably need to add the difference in > energy, i.e. 2 proton masses worth, or about 2 GeV. [snip]
It is very doubtful that the entire mass-energy of a proton is to be found in charge alone which is the implication of what you are saying. For instance, a neutron with no charge has about the same mass-energy as a charged proton. I suspect the energy needed to conjugate charge in the proton is about the same as the difference in mass between the neutron and proton. Far less. Jones