Guys: as de-facto representatives of physics and scientific rationality you have a duty of responsibility to this forum and its readers & posters. It's just not good enough to taunt, you have to give sound explanations supported by logic and evidence. If the respondent refuses to accept that, you should say
sorry, I can't help further, and gracefully withdraw. If he persists with unsupported claims, you should point it out firmly. But what you shouldn't do is come across as a bunch of sneering jackals.
Hi RC, how are you doing? Can I just point out that it isn't mass per se that causes or interacts with a gravitational field, it's energy. Or more properly a
concentration of energy over and above the background. A photon is such, and whilst not practically measureable, it does have a gravitational affect, and its path is curved in a gravitational field.
bjschaeffer: I've spoken to people about the neutron being a "multipole", something like -+- rather than a bipole +-. One issue that came out of that is
positron capture, which is mentioned
here. An atomic neutron can capture a positron. However we know of no "exotic atom" consisting of a free neutron bound with a positron, which suggests that we are dealing with something which isn't electromagnetism in the usual sense.
Dhamilton: The above touches upon the nature of "the strong force" and the "residual strong force" viz-a-viz plain vanilla electromagnetism, and IMHO gives a hint as to how they are related. One of the questions I particularly like concerns low-energy proton-antiproton annihilation to gamma photons:
where did the strong force go? The answer is perhaps a surprise. Anyway, I know what gravity is, and I know what light quanta are too. And I have integrity, and I will not slam you in the face. Talk to me.