Well, not really, but I am really struggling with understanding the motivation for its inclusion in the Standard Model; I'm hoping someone here might provide some guidance. My understanding of General Relativity is that gravitation is a purely local phenomenon; i.e. two massive entities in some sense 'appear' to be attracted to each other because the manifold upon which they reside is in fact curved. So it is really not a force at all but only an apparent one, and one which can be roughly described in most cases by Newtonian mechanics. But the graviton seems to be just an analogue of the photon; a mediating particle that (I assume) travels at the speed of light and is therefore not local at all, and in fact suggests that the gravitational 'force' would not be instantaneously 'felt', as it would be if it were a phenomenological manifestation of a local property. What gives here? Why introduce a particle without cause? William of Occam warned us against this sort of thing, didn't he? I'm just confused. Thanks!