We have been using binomial expansion techniques to analyze results from computation of the electric field for various charge distribution. We address, for example, the field of two point charges [each with charge q] along a line passing directly between the charges. As the distance from the charges becomes much larger than the separation between the charges, the field looks like a point charge of 2q. This reminded me of the Rayleigh Criterion for resolving two light sources and I was wondering whether a similar criterion exists for two point charges…hmmm. Is this even a reasonable question? Is there some situation in which it would be an important question?